https://citizendium.org/wiki/index.php?title=Wireless_telegraphy&feed=atom&action=historyWireless telegraphy - Revision history2024-03-29T11:01:07ZRevision history for this page on the wikiMediaWiki 1.39.5https://citizendium.org/wiki/index.php?title=Wireless_telegraphy&diff=21819&oldid=previmported>Ro Thorpe: /* Ground and water conduction */2017-04-09T20:17:18Z<p><span dir="auto"><span class="autocomment">Ground and water conduction</span></span></p>
<table style="background-color: #fff; color: #202122;" data-mw="interface">
<col class="diff-marker" />
<col class="diff-content" />
<col class="diff-marker" />
<col class="diff-content" />
<tr class="diff-title" lang="en">
<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 15:17, 9 April 2017</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l11">Line 11:</td>
<td colspan="2" class="diff-lineno">Line 11:</td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The earliest experiments with wireless telegraph transmissions date back to the beginnings of the electric telegraph. The original electric telegraphs employed both sending and return wires, in order to provide a complete electrical circuit for the message transmission. However, in 1837, Carl August von Steinheil of Munich, Germany found that, by connecting the terminal end of the sending wire to metal plates buried in the ground, the return wire could be eliminated, and only a single wire was needed for telegraphing. At the time, a common belief was that, with the single wire configuration, the return current was now traveling through the ground back to the sending point in order to complete the electrical circuit. This turned out to be incorrect, as the transmitted current was actually being absorbed into the earth at the receiving point, but it did lead to speculation that it might be possible to someday also eliminate the sending wire, and telegraph through the ground without using any wires at all.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The earliest experiments with wireless telegraph transmissions date back to the beginnings of the electric telegraph. The original electric telegraphs employed both sending and return wires, in order to provide a complete electrical circuit for the message transmission. However, in 1837, Carl August von Steinheil of Munich, Germany found that, by connecting the terminal end of the sending wire to metal plates buried in the ground, the return wire could be eliminated, and only a single wire was needed for telegraphing. At the time, a common belief was that, with the single wire configuration, the return current was now traveling through the ground back to the sending point in order to complete the electrical circuit. This turned out to be incorrect, as the transmitted current was actually being absorbed into the earth at the receiving point, but it did lead to speculation that it might be possible to someday also eliminate the sending wire, and telegraph through the ground without using any wires at all.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Other attempts were made to send telegraphic signals through bodies of water, for example, in order to span river crossings. Prominent experimenters along these lines included [[Samuel F. B. Morse]] in the United States and James Bowman Lindsay in Great Britain <del style="font-weight: bold; text-decoration: none;">&mdash</del>; in 1854 Lindsay demonstrated transmission across the Firth of Tay from Dundee to Woodhaven (now part of Newport-on-Tay), a distance of nearly 2 miles [3 kilometers]. However, because of the very high resistance to electrical currents, earth conductivity transmissions were found to be limited to only a few meters, and even the somewhat greater distances possible through water had little practical use.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Other attempts were made to send telegraphic signals through bodies of water, for example, in order to span river crossings. Prominent experimenters along these lines included [[Samuel F. B. Morse]] in the United States and James Bowman Lindsay in Great Britain; in 1854 Lindsay demonstrated transmission across the Firth of Tay from Dundee to Woodhaven (now part of Newport-on-Tay), a distance of nearly 2 miles [3 kilometers]. However, because of the very high resistance to electrical currents, earth conductivity transmissions were found to be limited to only a few meters, and even the somewhat greater distances possible through water had little practical use.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Electrostatic induction and electromagnetic induction==</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Electrostatic induction and electromagnetic induction==</div></td></tr>
</table>imported>Ro Thorpehttps://citizendium.org/wiki/index.php?title=Wireless_telegraphy&diff=175972&oldid=previmported>Ro Thorpe: /* Electrostatic Induction and Electromagnetic Induction */2017-04-09T20:16:09Z<p><span dir="auto"><span class="autocomment">Electrostatic Induction and Electromagnetic Induction</span></span></p>
<table style="background-color: #fff; color: #202122;" data-mw="interface">
<col class="diff-marker" />
<col class="diff-content" />
<col class="diff-marker" />
<col class="diff-content" />
<tr class="diff-title" lang="en">
<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 15:16, 9 April 2017</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l13">Line 13:</td>
<td colspan="2" class="diff-lineno">Line 13:</td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Other attempts were made to send telegraphic signals through bodies of water, for example, in order to span river crossings. Prominent experimenters along these lines included [[Samuel F. B. Morse]] in the United States and James Bowman Lindsay in Great Britain &mdash; in 1854 Lindsay demonstrated transmission across the Firth of Tay from Dundee to Woodhaven (now part of Newport-on-Tay), a distance of nearly 2 miles [3 kilometers]. However, because of the very high resistance to electrical currents, earth conductivity transmissions were found to be limited to only a few meters, and even the somewhat greater distances possible through water had little practical use.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Other attempts were made to send telegraphic signals through bodies of water, for example, in order to span river crossings. Prominent experimenters along these lines included [[Samuel F. B. Morse]] in the United States and James Bowman Lindsay in Great Britain &mdash; in 1854 Lindsay demonstrated transmission across the Firth of Tay from Dundee to Woodhaven (now part of Newport-on-Tay), a distance of nearly 2 miles [3 kilometers]. However, because of the very high resistance to electrical currents, earth conductivity transmissions were found to be limited to only a few meters, and even the somewhat greater distances possible through water had little practical use.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>==Electrostatic <del style="font-weight: bold; text-decoration: none;">Induction </del>and <del style="font-weight: bold; text-decoration: none;">Electromagnetic Induction</del>==</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>==Electrostatic <ins style="font-weight: bold; text-decoration: none;">induction </ins>and <ins style="font-weight: bold; text-decoration: none;">electromagnetic induction</ins>==</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Both electrostatic and electromagnetic induction were used to develop wireless telegraph systems that saw limited commercial application. In the United States, [[Thomas Edison]], in the mid-1880s, patented an electrostatic induction system he called "grasshopper telegraphy", which allowed telegraphic signals to jump the short distance between a running train and telegraph wires running parallel to the tracks. This system was successful technically but not economically, as there turned out to be little interest by train travelers in an on-board telegraph service. </div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Both electrostatic and electromagnetic induction were used to develop wireless telegraph systems that saw limited commercial application. In the United States, [[Thomas Edison]], in the mid-1880s, patented an electrostatic induction system he called "grasshopper telegraphy", which allowed telegraphic signals to jump the short distance between a running train and telegraph wires running parallel to the tracks. This system was successful technically but not economically, as there turned out to be little interest by train travelers in an on-board telegraph service. </div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The most successful creator of an electromagnetic induction system was William Preece in Great Britain, who began tests in 1882. By 1892 he was able to telegraph about 5 kilometers across the Bristol Channel. However, his induction system required extensive lengths of wire, many kilometers long, at both the sending and receiving ends, which made it impractical for use on ships or small islands, and the relatively short distances spanned meant it had few advantages over underwater cables.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The most successful creator of an electromagnetic induction system was William Preece in Great Britain, who began tests in 1882. By 1892 he was able to telegraph about 5 kilometers across the Bristol Channel. However, his induction system required extensive lengths of wire, many kilometers long, at both the sending and receiving ends, which made it impractical for use on ships or small islands, and the relatively short distances spanned meant it had few advantages over underwater cables.</div></td></tr>
<tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;"></ins></div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Electromagnetic radiation (radio)==</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Electromagnetic radiation (radio)==</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
</table>imported>Ro Thorpehttps://citizendium.org/wiki/index.php?title=Wireless_telegraphy&diff=175975&oldid=previmported>Ro Thorpe: /* Electromagnetic Radiation (Radio) */2017-04-09T19:57:01Z<p><span dir="auto"><span class="autocomment">Electromagnetic Radiation (Radio)</span></span></p>
<table style="background-color: #fff; color: #202122;" data-mw="interface">
<col class="diff-marker" />
<col class="diff-content" />
<col class="diff-marker" />
<col class="diff-content" />
<tr class="diff-title" lang="en">
<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 14:57, 9 April 2017</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l18">Line 18:</td>
<td colspan="2" class="diff-lineno">Line 18:</td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The most successful creator of an electromagnetic induction system was William Preece in Great Britain, who began tests in 1882. By 1892 he was able to telegraph about 5 kilometers across the Bristol Channel. However, his induction system required extensive lengths of wire, many kilometers long, at both the sending and receiving ends, which made it impractical for use on ships or small islands, and the relatively short distances spanned meant it had few advantages over underwater cables.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The most successful creator of an electromagnetic induction system was William Preece in Great Britain, who began tests in 1882. By 1892 he was able to telegraph about 5 kilometers across the Bristol Channel. However, his induction system required extensive lengths of wire, many kilometers long, at both the sending and receiving ends, which made it impractical for use on ships or small islands, and the relatively short distances spanned meant it had few advantages over underwater cables.</div></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>==Electromagnetic <del style="font-weight: bold; text-decoration: none;">Radiation </del>(<del style="font-weight: bold; text-decoration: none;">Radio</del>)==</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>==Electromagnetic <ins style="font-weight: bold; text-decoration: none;">radiation </ins>(<ins style="font-weight: bold; text-decoration: none;">radio</ins>)==</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>During the 1880s, German [[Heinrich Hertz]] demonstrated the production and reception of electromagnetic radiation (radio waves) in a series of groundbreaking experiments. This led to numerous experimenters working at using radio signals for wireless communication, initially with limited success. However, by 1897, [[Guglielmo Marconi]] had made a series of demonstrations in Great Britain which showed the practicality of using radio for signaling for far greater distances than had been achieved by any other means, which helped expand research worldwide.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>During the 1880s, German [[Heinrich Hertz]] demonstrated the production and reception of electromagnetic radiation (radio waves) in a series of groundbreaking experiments. This led to numerous experimenters working at using radio signals for wireless communication, initially with limited success. However, by 1897, [[Guglielmo Marconi]] had made a series of demonstrations in Great Britain which showed the practicality of using radio for signaling for far greater distances than had been achieved by any other means, which helped expand research worldwide.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>By the 1920s, there was a worldwide network of commercial and government radiotelegraphic stations, plus extensive use of radiotelegraphy aboard ships for navigational and commercial communication plus passenger messages. One sophisticated implementation of wireless telegraphy was telex using radio signals, developed in the 1940s, which <del style="font-weight: bold; text-decoration: none;">was </del>for many years provided the only reliable form of communication between many distant countries. The most advanced standard, CCITT R.44, automated both the routing and encoding of messages, which were transmitted using short wave radio.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>By the 1920s, there was a worldwide network of commercial and government radiotelegraphic stations, plus extensive use of radiotelegraphy aboard ships for navigational and commercial communication plus passenger messages. One sophisticated implementation of wireless telegraphy was telex using radio signals, developed in the 1940s, which for many years provided the only reliable form of communication between many distant countries. The most advanced standard, CCITT R.44, automated both the routing and encoding of messages, which were transmitted using short wave radio.</div></td></tr>
<tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Status==</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Status==</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>While radiotelegraphy had long been part of maritime safety, the requirement to monitor a Morse distress channel eventually was made obsolete in the [[Global Maritime Distress and Safety System]]. Radiotelegraphy still has limited use in some military and covert communications, and in [[amateur radio]].</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>While radiotelegraphy had long been part of maritime safety, the requirement to monitor a Morse distress channel eventually was made obsolete in the [[Global Maritime Distress and Safety System]]. Radiotelegraphy still has limited use in some military and covert communications, and in [[amateur radio]].</div></td></tr>
</table>imported>Ro Thorpehttps://citizendium.org/wiki/index.php?title=Wireless_telegraphy&diff=175966&oldid=previmported>Howard C. Berkowitz at 21:51, 17 June 20092009-06-17T21:51:55Z<p></p>
<table style="background-color: #fff; color: #202122;" data-mw="interface">
<col class="diff-marker" />
<col class="diff-content" />
<col class="diff-marker" />
<col class="diff-content" />
<tr class="diff-title" lang="en">
<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 16:51, 17 June 2009</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l1">Line 1:</td>
<td colspan="2" class="diff-lineno">Line 1:</td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>{{subpages}}</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>{{subpages}}</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>{{TOC|right}}</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>{{TOC|right}}</div></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>'''Wireless <del style="font-weight: bold; text-decoration: none;">Telegraphy</del>''' is electronic signaling through the ground, bodies of water, or the air, which does not require the direct metallic connection, from transmitter to receiver, that was needed by the original [[electric telegraph]]s. The term covers a number of related technologies developed beginning in the mid-1800s, including earth conduction, [[electrostatic induction]], [[electromagnetic induction]], and, most importantly, [[electromagnetic radiation]] ([[radio]]). In most implementations, [[Morse code]] was used for communication. </div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>'''Wireless <ins style="font-weight: bold; text-decoration: none;">telegraphy</ins>''' is electronic signaling through the ground, bodies of water, or the air, which does not require the direct metallic connection, from transmitter to receiver, that was needed by the original [[electric telegraph]]s. The term covers a number of related technologies developed beginning in the mid-1800s, including earth conduction, [[electrostatic induction]], [[electromagnetic induction]], and, most importantly, [[electromagnetic radiation]] ([[radio]]). In most implementations, [[Morse code]] was used for communication. </div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Radio proved to be by far the most efficient of these methods, so, beginning around 1900, most references to "wireless" actually mean radio transmissions, and for those purposes "wireless telegraph" was eventually supplanted by the more precise term "radiotelegraph". The term "radioteletype" emerged to describe non-Morse text transmission.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Radio proved to be by far the most efficient of these methods, so, beginning around 1900, most references to "wireless" actually mean radio transmissions, and for those purposes "wireless telegraph" was eventually supplanted by the more precise term "radiotelegraph". The term "radioteletype" emerged to describe non-Morse text transmission.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">While radiotelegraphy had long been part of maritime safety, the requirement to monitor a Morse distress channel eventually was made obsolete in the [[Global Maritime Distress and Safety System]]. Radiotelegraphy still has limited use in some military and covert communications, and in [[amateur radio]].</del></div></td><td colspan="2" class="diff-side-added"></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;"></del></div></td><td colspan="2" class="diff-side-added"></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">==History==</del></div></td><td colspan="2" class="diff-side-added"></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Multiple technologies fall under the term "wireless telegraphy", which sometimes creates confusion, as it is not always clearly stated exactly which form of "wireless" technology is being employed. For each of these technologies, signals are created by electrical currents, which, depending on the frequencies employed, produce different forms of radiation. However, often more than one type of radiation is being produced, which can make it difficult to determine which one is responsible for an observed effect. Among early experimenters, there was often significant uncertainty about exactly how they were producing their results. </div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Multiple technologies fall under the term "wireless telegraphy", which sometimes creates confusion, as it is not always clearly stated exactly which form of "wireless" technology is being employed. For each of these technologies, signals are created by electrical currents, which, depending on the frequencies employed, produce different forms of radiation. However, often more than one type of radiation is being produced, which can make it difficult to determine which one is responsible for an observed effect. Among early experimenters, there was often significant uncertainty about exactly how they were producing their results. </div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">=</del>==Ground and water conduction<del style="font-weight: bold; text-decoration: none;">=</del>==</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>==Ground and water conduction==</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The earliest experiments with wireless telegraph transmissions date back to the beginnings of the electric telegraph. The original electric telegraphs employed both sending and return wires, in order to provide a complete electrical circuit for the message transmission. However, in 1837, Carl August von Steinheil of Munich, Germany found that, by connecting the terminal end of the sending wire to metal plates buried in the ground, the return wire could be eliminated, and only a single wire was needed for telegraphing. At the time, a common belief was that, with the single wire configuration, the return current was now traveling through the ground back to the sending point in order to complete the electrical circuit. This turned out to be incorrect, as the transmitted current was actually being absorbed into the earth at the receiving point, but it did lead to speculation that it might be possible to someday also eliminate the sending wire, and telegraph through the ground without using any wires at all.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The earliest experiments with wireless telegraph transmissions date back to the beginnings of the electric telegraph. The original electric telegraphs employed both sending and return wires, in order to provide a complete electrical circuit for the message transmission. However, in 1837, Carl August von Steinheil of Munich, Germany found that, by connecting the terminal end of the sending wire to metal plates buried in the ground, the return wire could be eliminated, and only a single wire was needed for telegraphing. At the time, a common belief was that, with the single wire configuration, the return current was now traveling through the ground back to the sending point in order to complete the electrical circuit. This turned out to be incorrect, as the transmitted current was actually being absorbed into the earth at the receiving point, but it did lead to speculation that it might be possible to someday also eliminate the sending wire, and telegraph through the ground without using any wires at all.</div></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l16">Line 16:</td>
<td colspan="2" class="diff-lineno">Line 13:</td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Other attempts were made to send telegraphic signals through bodies of water, for example, in order to span river crossings. Prominent experimenters along these lines included [[Samuel F. B. Morse]] in the United States and James Bowman Lindsay in Great Britain &mdash; in 1854 Lindsay demonstrated transmission across the Firth of Tay from Dundee to Woodhaven (now part of Newport-on-Tay), a distance of nearly 2 miles [3 kilometers]. However, because of the very high resistance to electrical currents, earth conductivity transmissions were found to be limited to only a few meters, and even the somewhat greater distances possible through water had little practical use.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Other attempts were made to send telegraphic signals through bodies of water, for example, in order to span river crossings. Prominent experimenters along these lines included [[Samuel F. B. Morse]] in the United States and James Bowman Lindsay in Great Britain &mdash; in 1854 Lindsay demonstrated transmission across the Firth of Tay from Dundee to Woodhaven (now part of Newport-on-Tay), a distance of nearly 2 miles [3 kilometers]. However, because of the very high resistance to electrical currents, earth conductivity transmissions were found to be limited to only a few meters, and even the somewhat greater distances possible through water had little practical use.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">=</del>==Electrostatic Induction and Electromagnetic Induction<del style="font-weight: bold; text-decoration: none;">=</del>==</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>==Electrostatic Induction and Electromagnetic Induction==</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Both electrostatic and electromagnetic induction were used to develop wireless telegraph systems that saw limited commercial application. In the United States, [[Thomas Edison]], in the mid-1880s, patented an electrostatic induction system he called "grasshopper telegraphy", which allowed telegraphic signals to jump the short distance between a running train and telegraph wires running parallel to the tracks. This system was successful technically but not economically, as there turned out to be little interest by train travelers in an on-board telegraph service. </div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Both electrostatic and electromagnetic induction were used to develop wireless telegraph systems that saw limited commercial application. In the United States, [[Thomas Edison]], in the mid-1880s, patented an electrostatic induction system he called "grasshopper telegraphy", which allowed telegraphic signals to jump the short distance between a running train and telegraph wires running parallel to the tracks. This system was successful technically but not economically, as there turned out to be little interest by train travelers in an on-board telegraph service. </div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The most successful creator of an electromagnetic induction system was William Preece in Great Britain, who began tests in 1882. By 1892 he was able to telegraph about 5 kilometers across the Bristol Channel. However, his induction system required extensive lengths of wire, many kilometers long, at both the sending and receiving ends, which made it impractical for use on ships or small islands, and the relatively short distances spanned meant it had few advantages over underwater cables.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The most successful creator of an electromagnetic induction system was William Preece in Great Britain, who began tests in 1882. By 1892 he was able to telegraph about 5 kilometers across the Bristol Channel. However, his induction system required extensive lengths of wire, many kilometers long, at both the sending and receiving ends, which made it impractical for use on ships or small islands, and the relatively short distances spanned meant it had few advantages over underwater cables.</div></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div> </div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>==Electromagnetic Radiation (Radio)==</div></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">=</del>==Electromagnetic Radiation (Radio)<del style="font-weight: bold; text-decoration: none;">=</del>==</div></td><td colspan="2" class="diff-side-added"></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>During the 1880s, German [[Heinrich Hertz]] demonstrated the production and reception of electromagnetic radiation (radio waves) in a series of groundbreaking experiments. This led to numerous experimenters working at using radio signals for wireless communication, initially with limited success. However, by 1897, [[Guglielmo Marconi]] had made a series of demonstrations in Great Britain which showed the practicality of using radio for signaling for far greater distances than had been achieved by any other means, which helped expand research worldwide.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>During the 1880s, German [[Heinrich Hertz]] demonstrated the production and reception of electromagnetic radiation (radio waves) in a series of groundbreaking experiments. This led to numerous experimenters working at using radio signals for wireless communication, initially with limited success. However, by 1897, [[Guglielmo Marconi]] had made a series of demonstrations in Great Britain which showed the practicality of using radio for signaling for far greater distances than had been achieved by any other means, which helped expand research worldwide.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>By the 1920s, there was a worldwide network of commercial and government radiotelegraphic stations, plus extensive use of radiotelegraphy aboard ships for navigational and commercial communication plus passenger messages. One sophisticated implementation of wireless telegraphy was telex using radio signals, developed in the 1940s, which was for many years provided the only reliable form of communication between many distant countries. The most advanced standard, CCITT R.44, automated both the routing and encoding of messages, which were transmitted using short wave radio.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>By the 1920s, there was a worldwide network of commercial and government radiotelegraphic stations, plus extensive use of radiotelegraphy aboard ships for navigational and commercial communication plus passenger messages. One sophisticated implementation of wireless telegraphy was telex using radio signals, developed in the 1940s, which was for many years provided the only reliable form of communication between many distant countries. The most advanced standard, CCITT R.44, automated both the routing and encoding of messages, which were transmitted using short wave radio.</div></td></tr>
<tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">==Status==</ins></div></td></tr>
<tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">While radiotelegraphy had long been part of maritime safety, the requirement to monitor a Morse distress channel eventually was made obsolete in the [[Global Maritime Distress and Safety System]]. Radiotelegraphy still has limited use in some military and covert communications, and in [[amateur radio]].</ins></div></td></tr>
</table>imported>Howard C. Berkowitzhttps://citizendium.org/wiki/index.php?title=Wireless_telegraphy&diff=175968&oldid=previmported>Howard C. Berkowitz at 21:49, 17 June 20092009-06-17T21:49:33Z<p></p>
<table style="background-color: #fff; color: #202122;" data-mw="interface">
<col class="diff-marker" />
<col class="diff-content" />
<col class="diff-marker" />
<col class="diff-content" />
<tr class="diff-title" lang="en">
<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 16:49, 17 June 2009</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l1">Line 1:</td>
<td colspan="2" class="diff-lineno">Line 1:</td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>{{subpages}}</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>{{subpages}}</div></td></tr>
<tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">{{TOC|right}}</ins></div></td></tr>
<tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">'''Wireless Telegraphy''' is electronic signaling through the ground, bodies of water, or the air, which does not require the direct metallic connection, from transmitter to receiver, that was needed by the original [[electric telegraph]]s. The term covers a number of related technologies developed beginning in the mid-1800s, including earth conduction, [[electrostatic induction]], [[electromagnetic induction]], and, most importantly, [[electromagnetic radiation]] ([[radio]]). In most implementations, [[Morse code]] was used for communication. </ins></div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">'''Wireless Telegraphy''' is electronic signaling through </del>the <del style="font-weight: bold; text-decoration: none;">ground, bodies </del>of <del style="font-weight: bold; text-decoration: none;">water</del>, <del style="font-weight: bold; text-decoration: none;">or the air</del>, <del style="font-weight: bold; text-decoration: none;">which does not require the direct metallic connection</del>, <del style="font-weight: bold; text-decoration: none;">from transmitter </del>to <del style="font-weight: bold; text-decoration: none;">receiver</del>, <del style="font-weight: bold; text-decoration: none;">that </del>was <del style="font-weight: bold; text-decoration: none;">needed </del>by the <del style="font-weight: bold; text-decoration: none;">original [[electric telegraph]]s</del>. The term <del style="font-weight: bold; text-decoration: none;">covers a number of related technologies developed beginning in the mid</del>-<del style="font-weight: bold; text-decoration: none;">1800s, including earth conduction, [[electrostatic induction]], [[electromagnetic induction]], and, most importantly, [[electromagnetic radiation]] ([[radio]]). In most implementations, [[</del>Morse <del style="font-weight: bold; text-decoration: none;">code]] is used for communication</del>. </div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">Radio proved to be by far </ins>the <ins style="font-weight: bold; text-decoration: none;">most efficient </ins>of <ins style="font-weight: bold; text-decoration: none;">these methods</ins>, <ins style="font-weight: bold; text-decoration: none;">so</ins>, <ins style="font-weight: bold; text-decoration: none;">beginning around 1900</ins>, <ins style="font-weight: bold; text-decoration: none;">most references </ins>to <ins style="font-weight: bold; text-decoration: none;">"wireless" actually mean radio transmissions</ins>, <ins style="font-weight: bold; text-decoration: none;">and for those purposes "wireless telegraph" </ins>was <ins style="font-weight: bold; text-decoration: none;">eventually supplanted </ins>by the <ins style="font-weight: bold; text-decoration: none;">more precise term "radiotelegraph"</ins>. The term <ins style="font-weight: bold; text-decoration: none;">"radioteletype" emerged to describe non</ins>-Morse <ins style="font-weight: bold; text-decoration: none;">text transmission</ins>.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">Radio proved to be by far the most efficient </del>of <del style="font-weight: bold; text-decoration: none;">these methods</del>, <del style="font-weight: bold; text-decoration: none;">so, beginning around 1900, most references </del>to <del style="font-weight: bold; text-decoration: none;">"wireless" actually mean radio transmissions, and for those purposes "wireless telegraph" </del>was <del style="font-weight: bold; text-decoration: none;">eventually supplanted by </del>the <del style="font-weight: bold; text-decoration: none;">more precise term "radiotelegraph"</del>. <del style="font-weight: bold; text-decoration: none;">But</del>, <del style="font-weight: bold; text-decoration: none;">with the eventual near-disappearance of telegraphic signaling, even this latter term is now very rarely used, although text messaging by mobile telephone can be considered a form of radiotelegraphy</del>.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">While radiotelegraphy had long been part </ins>of <ins style="font-weight: bold; text-decoration: none;">maritime safety</ins>, <ins style="font-weight: bold; text-decoration: none;">the requirement </ins>to <ins style="font-weight: bold; text-decoration: none;">monitor a Morse distress channel eventually </ins>was <ins style="font-weight: bold; text-decoration: none;">made obsolete in </ins>the <ins style="font-weight: bold; text-decoration: none;">[[Global Maritime Distress and Safety System]]</ins>. <ins style="font-weight: bold; text-decoration: none;">Radiotelegraphy still has limited use in some military and covert communications</ins>, <ins style="font-weight: bold; text-decoration: none;">and in [[amateur radio]]</ins>.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==History==</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==History==</div></td></tr>
</table>imported>Howard C. Berkowitzhttps://citizendium.org/wiki/index.php?title=Wireless_telegraphy&diff=175970&oldid=previmported>Thomas H. White: Transfer Bibliography and External Links to subpages2007-11-17T11:55:54Z<p>Transfer Bibliography and External Links to subpages</p>
<table style="background-color: #fff; color: #202122;" data-mw="interface">
<col class="diff-marker" />
<col class="diff-content" />
<col class="diff-marker" />
<col class="diff-content" />
<tr class="diff-title" lang="en">
<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 06:55, 17 November 2007</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l24">Line 24:</td>
<td colspan="2" class="diff-lineno">Line 24:</td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>During the 1880s, German [[Heinrich Hertz]] demonstrated the production and reception of electromagnetic radiation (radio waves) in a series of groundbreaking experiments. This led to numerous experimenters working at using radio signals for wireless communication, initially with limited success. However, by 1897, [[Guglielmo Marconi]] had made a series of demonstrations in Great Britain which showed the practicality of using radio for signaling for far greater distances than had been achieved by any other means, which helped expand research worldwide.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>During the 1880s, German [[Heinrich Hertz]] demonstrated the production and reception of electromagnetic radiation (radio waves) in a series of groundbreaking experiments. This led to numerous experimenters working at using radio signals for wireless communication, initially with limited success. However, by 1897, [[Guglielmo Marconi]] had made a series of demonstrations in Great Britain which showed the practicality of using radio for signaling for far greater distances than had been achieved by any other means, which helped expand research worldwide.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>By the 1920s, there was a worldwide network of commercial and government radiotelegraphic stations, plus extensive use of radiotelegraphy aboard ships for navigational and commercial communication plus passenger messages. One sophisticated implementation of wireless telegraphy was telex using radio signals, developed in the 1940s, which was for many years provided the only reliable form of communication between many distant countries. The most advanced standard, CCITT R.44, automated both the routing and encoding of messages, which were transmitted using short wave radio. </div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>By the 1920s, there was a worldwide network of commercial and government radiotelegraphic stations, plus extensive use of radiotelegraphy aboard ships for navigational and commercial communication plus passenger messages. One sophisticated implementation of wireless telegraphy was telex using radio signals, developed in the 1940s, which was for many years provided the only reliable form of communication between many distant countries. The most advanced standard, CCITT R.44, automated both the routing and encoding of messages, which were transmitted using short wave radio.</div></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div> </div></td><td colspan="2" class="diff-side-added"></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">==Further reading==</del></div></td><td colspan="2" class="diff-side-added"></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div> </div></td><td colspan="2" class="diff-side-added"></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">* Hugh G. J. Aitken, ''Syntony and Spark: the Origins of Radio'', ISBN 0-471-01816-3.</del></div></td><td colspan="2" class="diff-side-added"></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">* Elliot N. Sivowitch, ''A Technological Survey of Broadcasting’s Pre-History,'' Journal of Broadcasting, 15:1-20 (Winter 1970-71).</del></div></td><td colspan="2" class="diff-side-added"></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div> </div></td><td colspan="2" class="diff-side-added"></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">==Online resources==</del></div></td><td colspan="2" class="diff-side-added"></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div> </div></td><td colspan="2" class="diff-side-added"></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">* John Joseph Fahie, [http://www.archive.org/details/historyofwireles00fahirich ''A History of Wireless Telegraphy, 1838-1899: including some bare-wire proposals for subaqueous telegraphs''], 1899 (first edition).</del></div></td><td colspan="2" class="diff-side-added"></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">* John Joseph Fahie, [http://www.archive.org/details/historywirelesst00fahirich ''A History of Wireless Telegraphy: including some bare-wire proposals for subaqueous telegraphs''], 1901 (second edition).</del></div></td><td colspan="2" class="diff-side-added"></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">* John Joseph Fahie, [http://earlyradiohistory.us/1901fa.htm ''A History of Wireless Telegraphy: including some bare-wire proposals for subaqueous telegraphs''], 1901 (second edition, in HTML format).</del></div></td><td colspan="2" class="diff-side-added"></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">* [http://home.frognet.net/~ejcov/lindsay3.html James Bowman Lindsay] A short biography on his efforts on electric lamps and telegraphy.</del></div></td><td colspan="2" class="diff-side-added"></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">* [http://www.zianet.com/sparks/ Sparks Telegraph Key Review]</del></div></td><td colspan="2" class="diff-side-added"></td></tr>
</table>imported>Thomas H. Whitehttps://citizendium.org/wiki/index.php?title=Wireless_telegraphy&diff=175973&oldid=previmported>Subpagination Bot: Add {{subpages}} and remove any categories (details)2007-11-16T05:54:02Z<p>Add {{subpages}} and remove any categories (<a href="/wiki/User:Subpagination_Bot/Task_1" title="User:Subpagination Bot/Task 1">details</a>)</p>
<table style="background-color: #fff; color: #202122;" data-mw="interface">
<col class="diff-marker" />
<col class="diff-content" />
<col class="diff-marker" />
<col class="diff-content" />
<tr class="diff-title" lang="en">
<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 00:54, 16 November 2007</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l1">Line 1:</td>
<td colspan="2" class="diff-lineno">Line 1:</td></tr>
<tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">{{subpages}}</ins></div></td></tr>
<tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;"></ins></div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''Wireless Telegraphy''' is electronic signaling through the ground, bodies of water, or the air, which does not require the direct metallic connection, from transmitter to receiver, that was needed by the original [[electric telegraph]]s. The term covers a number of related technologies developed beginning in the mid-1800s, including earth conduction, [[electrostatic induction]], [[electromagnetic induction]], and, most importantly, [[electromagnetic radiation]] ([[radio]]). In most implementations, [[Morse code]] is used for communication. </div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''Wireless Telegraphy''' is electronic signaling through the ground, bodies of water, or the air, which does not require the direct metallic connection, from transmitter to receiver, that was needed by the original [[electric telegraph]]s. The term covers a number of related technologies developed beginning in the mid-1800s, including earth conduction, [[electrostatic induction]], [[electromagnetic induction]], and, most importantly, [[electromagnetic radiation]] ([[radio]]). In most implementations, [[Morse code]] is used for communication. </div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l36">Line 36:</td>
<td colspan="2" class="diff-lineno">Line 38:</td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* [http://home.frognet.net/~ejcov/lindsay3.html James Bowman Lindsay] A short biography on his efforts on electric lamps and telegraphy.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* [http://home.frognet.net/~ejcov/lindsay3.html James Bowman Lindsay] A short biography on his efforts on electric lamps and telegraphy.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* [http://www.zianet.com/sparks/ Sparks Telegraph Key Review]</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* [http://www.zianet.com/sparks/ Sparks Telegraph Key Review]</div></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;"></del></div></td><td colspan="2" class="diff-side-added"></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">[[Category:CZ Live]]</del></div></td><td colspan="2" class="diff-side-added"></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">[[Category:Media Workgroup]]</del></div></td><td colspan="2" class="diff-side-added"></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">[[Category:Engineering Workgroup]]</del></div></td><td colspan="2" class="diff-side-added"></td></tr>
</table>imported>Subpagination Bothttps://citizendium.org/wiki/index.php?title=Wireless_telegraphy&diff=175974&oldid=previmported>Thomas H. White: Mainly remove links that don't exist yet2007-04-12T00:01:01Z<p>Mainly remove links that don't exist yet</p>
<table style="background-color: #fff; color: #202122;" data-mw="interface">
<col class="diff-marker" />
<col class="diff-content" />
<col class="diff-marker" />
<col class="diff-content" />
<tr class="diff-title" lang="en">
<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 19:01, 11 April 2007</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l1">Line 1:</td>
<td colspan="2" class="diff-lineno">Line 1:</td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''Wireless Telegraphy''' is electronic signaling through the ground, bodies of water, or the air, which does not require the direct metallic connection, from transmitter to receiver, that was needed by the original [[electric telegraph]]s. The term covers a number of related technologies developed beginning in the mid-1800s, including earth conduction, [[electrostatic induction]], [[electromagnetic induction]], and, most importantly, [[electromagnetic radiation]] ([[radio]]). In most implementations, [[Morse code]] is used for communication. </div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''Wireless Telegraphy''' is electronic signaling through the ground, bodies of water, or the air, which does not require the direct metallic connection, from transmitter to receiver, that was needed by the original [[electric telegraph]]s. The term covers a number of related technologies developed beginning in the mid-1800s, including earth conduction, [[electrostatic induction]], [[electromagnetic induction]], and, most importantly, [[electromagnetic radiation]] ([[radio]]). In most implementations, [[Morse code]] is used for communication. </div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Radio proved to be by far the most efficient of these methods, so, beginning around 1900, most references to "wireless" actually mean radio transmissions, and for those purposes "wireless telegraph" was eventually supplanted by the more precise term "radiotelegraph". But, with the eventual near-disappearance of telegraphic <del style="font-weight: bold; text-decoration: none;">signalling</del>, even this latter term is now very rarely used, although <del style="font-weight: bold; text-decoration: none;">[[</del>text messaging<del style="font-weight: bold; text-decoration: none;">]] </del>by <del style="font-weight: bold; text-decoration: none;">[[</del>mobile telephone<del style="font-weight: bold; text-decoration: none;">]] </del>can be considered a form of radiotelegraphy.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Radio proved to be by far the most efficient of these methods, so, beginning around 1900, most references to "wireless" actually mean radio transmissions, and for those purposes "wireless telegraph" was eventually supplanted by the more precise term "radiotelegraph". But, with the eventual near-disappearance of telegraphic <ins style="font-weight: bold; text-decoration: none;">signaling</ins>, even this latter term is now very rarely used, although text messaging by mobile telephone can be considered a form of radiotelegraphy.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==History==</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==History==</div></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l8">Line 8:</td>
<td colspan="2" class="diff-lineno">Line 8:</td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Ground and water conduction===</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Ground and water conduction===</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>The earliest experiments with wireless telegraph transmissions date back to the beginnings of the electric telegraph. The original electric telegraphs employed both sending and return wires, in order to provide a complete electrical circuit for the message transmission. However, in 1837, <del style="font-weight: bold; text-decoration: none;">[[</del>Carl August von Steinheil<del style="font-weight: bold; text-decoration: none;">]] </del>of Munich, Germany found that, by connecting the terminal end of the sending wire to metal plates buried in the ground, the return wire could be eliminated, and only a single wire was needed for telegraphing. At the time, a common belief was that, with the single wire configuration, the return current was now traveling through the ground back to the sending point in order to complete the electrical circuit. This turned out to be incorrect, as the transmitted current was actually being absorbed into the earth at the receiving point, but it did lead to speculation that it might be possible to someday also eliminate the sending wire, and telegraph through the ground without using any wires at all.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>The earliest experiments with wireless telegraph transmissions date back to the beginnings of the electric telegraph. The original electric telegraphs employed both sending and return wires, in order to provide a complete electrical circuit for the message transmission. However, in 1837, Carl August von Steinheil of Munich, Germany found that, by connecting the terminal end of the sending wire to metal plates buried in the ground, the return wire could be eliminated, and only a single wire was needed for telegraphing. At the time, a common belief was that, with the single wire configuration, the return current was now traveling through the ground back to the sending point in order to complete the electrical circuit. This turned out to be incorrect, as the transmitted current was actually being absorbed into the earth at the receiving point, but it did lead to speculation that it might be possible to someday also eliminate the sending wire, and telegraph through the ground without using any wires at all.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Other attempts were made to send telegraphic signals through bodies of water, for example, in order to span river crossings. Prominent experimenters along these lines included [[Samuel F. B. Morse]] in the United States and James Bowman Lindsay in Great Britain &mdash; in 1854 Lindsay demonstrated transmission across the Firth of Tay from Dundee to Woodhaven (now part of Newport-on-Tay), a distance of nearly 2 miles [3 kilometers]<del style="font-weight: bold; text-decoration: none;">.</del>. However, because of the very high resistance to electrical currents, earth conductivity transmissions were found to be limited to only a few meters, and even the somewhat greater distances possible through water had little practical use.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Other attempts were made to send telegraphic signals through bodies of water, for example, in order to span river crossings. Prominent experimenters along these lines included [[Samuel F. B. Morse]] in the United States and James Bowman Lindsay in Great Britain &mdash; in 1854 Lindsay demonstrated transmission across the Firth of Tay from Dundee to Woodhaven (now part of Newport-on-Tay), a distance of nearly 2 miles [3 kilometers]. However, because of the very high resistance to electrical currents, earth conductivity transmissions were found to be limited to only a few meters, and even the somewhat greater distances possible through water had little practical use.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Electrostatic Induction and Electromagnetic Induction===</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Electrostatic Induction and Electromagnetic Induction===</div></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l16">Line 16:</td>
<td colspan="2" class="diff-lineno">Line 16:</td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Both electrostatic and electromagnetic induction were used to develop wireless telegraph systems that saw limited commercial application. In the United States, [[Thomas Edison]], in the mid-1880s, patented an electrostatic induction system he called "grasshopper telegraphy", which allowed telegraphic signals to jump the short distance between a running train and telegraph wires running parallel to the tracks. This system was successful technically but not economically, as there turned out to be little interest by train travelers in an on-board telegraph service. </div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Both electrostatic and electromagnetic induction were used to develop wireless telegraph systems that saw limited commercial application. In the United States, [[Thomas Edison]], in the mid-1880s, patented an electrostatic induction system he called "grasshopper telegraphy", which allowed telegraphic signals to jump the short distance between a running train and telegraph wires running parallel to the tracks. This system was successful technically but not economically, as there turned out to be little interest by train travelers in an on-board telegraph service. </div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>The most successful creator of an electromagnetic induction system was <del style="font-weight: bold; text-decoration: none;">[[</del>William Preece<del style="font-weight: bold; text-decoration: none;">]] </del>in Great Britain, who began tests in 1882. By 1892 he was able to telegraph about 5 kilometers across the Bristol Channel. However, his induction system required extensive lengths of wire, many kilometers long, at both the sending and receiving ends, which made it impractical for use on ships or small islands, and the relatively short distances spanned meant it had few advantages over underwater cables.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>The most successful creator of an electromagnetic induction system was William Preece in Great Britain, who began tests in 1882. By 1892 he was able to telegraph about 5 kilometers across the Bristol Channel. However, his induction system required extensive lengths of wire, many kilometers long, at both the sending and receiving ends, which made it impractical for use on ships or small islands, and the relatively short distances spanned meant it had few advantages over underwater cables.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Electromagnetic Radiation (Radio)===</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Electromagnetic Radiation (Radio)===</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>During the 1880s, German [[Heinrich Hertz]] demonstrated the production and reception of electromagnetic radiation (radio waves) in a series of groundbreaking experiments. This led to numerous experimenters working at using radio signals for wireless communication, initially with limited success. However, by 1897, [[Guglielmo Marconi]] had made a series of demonstrations in Great Britain which showed the practicality of using radio for <del style="font-weight: bold; text-decoration: none;">signalling </del>for far greater distances than had been achieved by any other means, which helped expand research worldwide.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>During the 1880s, German [[Heinrich Hertz]] demonstrated the production and reception of electromagnetic radiation (radio waves) in a series of groundbreaking experiments. This led to numerous experimenters working at using radio signals for wireless communication, initially with limited success. However, by 1897, [[Guglielmo Marconi]] had made a series of demonstrations in Great Britain which showed the practicality of using radio for <ins style="font-weight: bold; text-decoration: none;">signaling </ins>for far greater distances than had been achieved by any other means, which helped expand research worldwide.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>By the 1920s, there was a worldwide network of commercial and government radiotelegraphic stations, plus extensive use of radiotelegraphy aboard ships for navigational and commercial communication plus passenger messages. One sophisticated implementation of wireless telegraphy was <del style="font-weight: bold; text-decoration: none;">[[teleprinter|</del>telex<del style="font-weight: bold; text-decoration: none;">]] </del>using radio signals, developed in the 1940s, which was for many years provided the only reliable form of communication between many distant countries. The most advanced standard, <del style="font-weight: bold; text-decoration: none;">[[ITU-T|</del>CCITT<del style="font-weight: bold; text-decoration: none;">]] [[</del>R.44<del style="font-weight: bold; text-decoration: none;">]]</del>, automated both the routing and encoding of messages, which were transmitted using <del style="font-weight: bold; text-decoration: none;">[[</del>short wave<del style="font-weight: bold; text-decoration: none;">]] </del>radio. </div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>By the 1920s, there was a worldwide network of commercial and government radiotelegraphic stations, plus extensive use of radiotelegraphy aboard ships for navigational and commercial communication plus passenger messages. One sophisticated implementation of wireless telegraphy was telex using radio signals, developed in the 1940s, which was for many years provided the only reliable form of communication between many distant countries. The most advanced standard, CCITT R.44, automated both the routing and encoding of messages, which were transmitted using short wave radio<ins style="font-weight: bold; text-decoration: none;">. </ins></div></td></tr>
<tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">==Further reading==</ins></div></td></tr>
<tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">* Hugh G. J. Aitken, ''Syntony and Spark: the Origins of Radio'', ISBN 0-471-01816-3.</ins></div></td></tr>
<tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">* Elliot N. Sivowitch, ''A Technological Survey of Broadcasting’s Pre-History,'' Journal of Broadcasting, 15:1-20 (Winter 1970-71)</ins>.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Online resources==</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Online resources==</div></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l31">Line 31:</td>
<td colspan="2" class="diff-lineno">Line 36:</td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* [http://home.frognet.net/~ejcov/lindsay3.html James Bowman Lindsay] A short biography on his efforts on electric lamps and telegraphy.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* [http://home.frognet.net/~ejcov/lindsay3.html James Bowman Lindsay] A short biography on his efforts on electric lamps and telegraphy.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* [http://www.zianet.com/sparks/ Sparks Telegraph Key Review]</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* [http://www.zianet.com/sparks/ Sparks Telegraph Key Review]</div></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;"></del></div></td><td colspan="2" class="diff-side-added"></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">==Further reading==</del></div></td><td colspan="2" class="diff-side-added"></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;"></del></div></td><td colspan="2" class="diff-side-added"></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">* Hugh G. J. Aitken, ''Syntony and Spark: the Origins of Radio'', ISBN 0-471-01816-3.</del></div></td><td colspan="2" class="diff-side-added"></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">* Elliot N. Sivowitch, ''A Technological Survey of Broadcasting’s Pre-History,'' Journal of Broadcasting, 15:1-20 (Winter 1970-71).</del></div></td><td colspan="2" class="diff-side-added"></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Category:CZ Live]]</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Category:CZ Live]]</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Category:Media Workgroup]]</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Category:Media Workgroup]]</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Category:Engineering Workgroup]]</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Category:Engineering Workgroup]]</div></td></tr>
</table>imported>Thomas H. Whitehttps://citizendium.org/wiki/index.php?title=Wireless_telegraphy&diff=175976&oldid=previmported>Thomas H. White: Copyediting2007-04-06T17:00:56Z<p>Copyediting</p>
<table style="background-color: #fff; color: #202122;" data-mw="interface">
<col class="diff-marker" />
<col class="diff-content" />
<col class="diff-marker" />
<col class="diff-content" />
<tr class="diff-title" lang="en">
<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 12:00, 6 April 2007</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l8">Line 8:</td>
<td colspan="2" class="diff-lineno">Line 8:</td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Ground and water conduction===</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Ground and water conduction===</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>The earliest experiments with wireless telegraph transmissions date back to the beginnings of the electric telegraph. The original electric telegraphs employed both sending and return wires, in order to provide a complete electrical circuit for the message transmission. However, in 1837, [[Carl August von Steinheil]] of Munich, Germany found that, by connecting the terminal end of the sending wire to metal plates buried in the ground, the return wire could be eliminated, and only a single wire was needed for telegraphing. At the time, a common belief was that, with the single wire configuration, the return current was now traveling through the ground back to the sending point in order to complete the electrical circuit. This turned out to be incorrect, as the transmitted current was actually being absorbed into the earth at the receiving point, but it did lead to speculation that it might be possible to someday also eliminate the sending wire, and telegraph through the ground without using any wires at all. Other attempts were made to send through bodies of water, for example, in order to span river crossings. Prominent experimenters along these lines included [[Samuel F. B. Morse]] in the United States and James Bowman Lindsay in Great Britain &mdash; in 1854 Lindsay demonstrated transmission across the Firth of Tay from Dundee to Woodhaven (now part of Newport-on-Tay), a distance of nearly 2 miles [3 kilometers].. However, because of the very high resistance to electrical currents, earth conductivity transmissions were found to be limited to only a few meters, and even the somewhat greater distances possible through water had little practical use.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>The earliest experiments with wireless telegraph transmissions date back to the beginnings of the electric telegraph. The original electric telegraphs employed both sending and return wires, in order to provide a complete electrical circuit for the message transmission. However, in 1837, [[Carl August von Steinheil]] of Munich, Germany found that, by connecting the terminal end of the sending wire to metal plates buried in the ground, the return wire could be eliminated, and only a single wire was needed for telegraphing. At the time, a common belief was that, with the single wire configuration, the return current was now traveling through the ground back to the sending point in order to complete the electrical circuit. This turned out to be incorrect, as the transmitted current was actually being absorbed into the earth at the receiving point, but it did lead to speculation that it might be possible to someday also eliminate the sending wire, and telegraph through the ground without using any wires at all.</div></td></tr>
<tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Other attempts were made to send <ins style="font-weight: bold; text-decoration: none;">telegraphic signals </ins>through bodies of water, for example, in order to span river crossings. Prominent experimenters along these lines included [[Samuel F. B. Morse]] in the United States and James Bowman Lindsay in Great Britain &mdash; in 1854 Lindsay demonstrated transmission across the Firth of Tay from Dundee to Woodhaven (now part of Newport-on-Tay), a distance of nearly 2 miles [3 kilometers].. However, because of the very high resistance to electrical currents, earth conductivity transmissions were found to be limited to only a few meters, and even the somewhat greater distances possible through water had little practical use.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Electrostatic Induction and Electromagnetic Induction===</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Electrostatic Induction and Electromagnetic Induction===</div></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l18">Line 18:</td>
<td colspan="2" class="diff-lineno">Line 20:</td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Electromagnetic Radiation (Radio)===</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Electromagnetic Radiation (Radio)===</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>[[Heinrich Hertz]] demonstrated the <del style="font-weight: bold; text-decoration: none;">existence </del>of electromagnetic radiation (radio waves) in a series of groundbreaking experiments <del style="font-weight: bold; text-decoration: none;">in Germany during the 1880s</del>. This led to <del style="font-weight: bold; text-decoration: none;">work by </del>numerous experimenters <del style="font-weight: bold; text-decoration: none;">in </del>using radio signals for wireless communication, initially with limited success. However, by 1897, [[Guglielmo Marconi]] had made a series of demonstrations in Great Britain which showed the practicality of using radio for signalling far greater distances than had been achieved by any other means, which <del style="font-weight: bold; text-decoration: none;">led to an explosion of activity </del>worldwide.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">During the 1880s, German </ins>[[Heinrich Hertz]] demonstrated the <ins style="font-weight: bold; text-decoration: none;">production and reception </ins>of electromagnetic radiation (radio waves) in a series of groundbreaking experiments. This led to <ins style="font-weight: bold; text-decoration: none;"> </ins>numerous experimenters <ins style="font-weight: bold; text-decoration: none;">working at </ins>using radio signals for wireless communication, initially with limited success. However, by 1897, [[Guglielmo Marconi]] had made a series of demonstrations in Great Britain which showed the practicality of using radio for signalling <ins style="font-weight: bold; text-decoration: none;">for </ins>far greater distances than had been achieved by any other means, which <ins style="font-weight: bold; text-decoration: none;">helped expand research </ins>worldwide.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>By the 1920s, there was a worldwide network of commercial and government radiotelegraphic stations, plus extensive use of radiotelegraphy <del style="font-weight: bold; text-decoration: none;">by </del>ships for <del style="font-weight: bold; text-decoration: none;">both </del>commercial <del style="font-weight: bold; text-decoration: none;">purposes and </del>passenger messages. <del style="font-weight: bold; text-decoration: none;">The ultimate </del>implementation of wireless telegraphy was [[teleprinter|telex]] using radio signals, <del style="font-weight: bold; text-decoration: none;">which was </del>developed in the 1940s, <del style="font-weight: bold; text-decoration: none;">and </del>was for many years the only reliable form of communication between many distant countries. The most advanced standard, [[ITU-T|CCITT]] [[R.44]], automated both routing and encoding of messages <del style="font-weight: bold; text-decoration: none;">by </del>[[short wave]] <del style="font-weight: bold; text-decoration: none;">transmissions</del>. </div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>By the 1920s, there was a worldwide network of commercial and government radiotelegraphic stations, plus extensive use of radiotelegraphy <ins style="font-weight: bold; text-decoration: none;">aboard </ins>ships for <ins style="font-weight: bold; text-decoration: none;">navigational and </ins>commercial <ins style="font-weight: bold; text-decoration: none;">communication plus </ins>passenger messages. <ins style="font-weight: bold; text-decoration: none;">One sophisticated </ins>implementation of wireless telegraphy was [[teleprinter|telex]] using radio signals, developed in the 1940s, <ins style="font-weight: bold; text-decoration: none;">which </ins>was for many years <ins style="font-weight: bold; text-decoration: none;">provided </ins>the only reliable form of communication between many distant countries. The most advanced standard, [[ITU-T|CCITT]] [[R.44]], automated both <ins style="font-weight: bold; text-decoration: none;">the </ins>routing and encoding of messages<ins style="font-weight: bold; text-decoration: none;">, which were transmitted using </ins>[[short wave]] <ins style="font-weight: bold; text-decoration: none;">radio</ins>. </div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Online resources==</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Online resources==</div></td></tr>
</table>imported>Thomas H. Whitehttps://citizendium.org/wiki/index.php?title=Wireless_telegraphy&diff=175971&oldid=previmported>Thomas H. White: Copyediting, rewording.2007-04-06T11:58:34Z<p>Copyediting, rewording.</p>
<table style="background-color: #fff; color: #202122;" data-mw="interface">
<col class="diff-marker" />
<col class="diff-content" />
<col class="diff-marker" />
<col class="diff-content" />
<tr class="diff-title" lang="en">
<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 06:58, 6 April 2007</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l4">Line 4:</td>
<td colspan="2" class="diff-lineno">Line 4:</td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==History==</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==History==</div></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">The fact that multiple </del>technologies fall under the term "wireless telegraphy" sometimes creates confusion, as it is not always <del style="font-weight: bold; text-decoration: none;">made clear </del>exactly <del style="font-weight: bold; text-decoration: none;">what </del>form of "wireless" technology is being employed. <del style="font-weight: bold; text-decoration: none;">All </del>of these technologies <del style="font-weight: bold; text-decoration: none;">create </del>signals <del style="font-weight: bold; text-decoration: none;">via </del>electrical currents, which, depending on the frequencies employed, produce different forms of radiation. <del style="font-weight: bold; text-decoration: none;">Moreover</del>, often more than one <del style="font-weight: bold; text-decoration: none;">form </del>of radiation is produced, which <del style="font-weight: bold; text-decoration: none;">makes </del>it difficult to <del style="font-weight: bold; text-decoration: none;">analyze </del>which <del style="font-weight: bold; text-decoration: none;">form </del>is responsible for <del style="font-weight: bold; text-decoration: none;">the </del>observed <del style="font-weight: bold; text-decoration: none;">effects</del>. Among early experimenters there was often uncertainty about exactly how they were producing <del style="font-weight: bold; text-decoration: none;">the </del>results <del style="font-weight: bold; text-decoration: none;">which they saw</del>. </div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">Multiple </ins>technologies fall under the term "wireless telegraphy"<ins style="font-weight: bold; text-decoration: none;">, which </ins>sometimes creates confusion, as it is not always <ins style="font-weight: bold; text-decoration: none;">clearly stated </ins>exactly <ins style="font-weight: bold; text-decoration: none;">which </ins>form of "wireless" technology is being employed. <ins style="font-weight: bold; text-decoration: none;">For each </ins>of these technologies<ins style="font-weight: bold; text-decoration: none;">, </ins>signals <ins style="font-weight: bold; text-decoration: none;">are created by </ins>electrical currents, which, depending on the frequencies employed, produce different forms of radiation. <ins style="font-weight: bold; text-decoration: none;">However</ins>, often more than one <ins style="font-weight: bold; text-decoration: none;">type </ins>of radiation is <ins style="font-weight: bold; text-decoration: none;">being </ins>produced, which <ins style="font-weight: bold; text-decoration: none;">can make </ins>it difficult to <ins style="font-weight: bold; text-decoration: none;">determine </ins>which <ins style="font-weight: bold; text-decoration: none;">one </ins>is responsible for <ins style="font-weight: bold; text-decoration: none;">an </ins>observed <ins style="font-weight: bold; text-decoration: none;">effect</ins>. Among early experimenters<ins style="font-weight: bold; text-decoration: none;">, </ins>there was often <ins style="font-weight: bold; text-decoration: none;">significant </ins>uncertainty about exactly how they were producing <ins style="font-weight: bold; text-decoration: none;">their </ins>results. </div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Ground and water conduction===</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Ground and water conduction===</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>The earliest <del style="font-weight: bold; text-decoration: none;">thoughts about </del>wireless telegraph transmissions date back to the <del style="font-weight: bold; text-decoration: none;">initial development </del>of the electric telegraph. The original telegraphs <del style="font-weight: bold; text-decoration: none;">included </del>both sending and return wires, in order to provide a complete electrical circuit for the message transmission. However, in 1837, [[Carl August von Steinheil]] of Munich, Germany found that, by connecting the terminal end of the sending wire to metal plates buried in the ground, the return wire could be eliminated, and only a single wire <del style="font-weight: bold; text-decoration: none;">used </del>for telegraphing. At the time, a common belief was that with <del style="font-weight: bold; text-decoration: none;">this </del>configuration the return current was now traveling through the ground back to the sending point<del style="font-weight: bold; text-decoration: none;">, </del>in order to complete the circuit. This turned out to be incorrect, but it did lead to speculation that it might be possible to someday also eliminate the sending wire, and telegraph through the ground without using any wires at all. Other attempts were made to send through bodies of water, for example, in order to span river crossings. Prominent experimenters along these lines included [[Samuel F. B. Morse]] in the United States and <del style="font-weight: bold; text-decoration: none;">[[</del>James Bowman Lindsay<del style="font-weight: bold; text-decoration: none;">]] </del>in Great Britain &mdash; in 1854 Lindsay demonstrated transmission across the Firth of Tay from Dundee to Woodhaven (now part of Newport-on-Tay), a distance of nearly 2 miles [3 kilometers] <del style="font-weight: bold; text-decoration: none;"><ref>Fahie, J. J., ''A History of Wireless Telegraphy, 1838-1899'', 1899, p</del>. <del style="font-weight: bold; text-decoration: none;">29</ref></del>. However, because of the very high resistance to electrical currents, earth conductivity transmissions were found to be limited to only a few meters, and even the somewhat greater distances possible through water had little practical use.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>The earliest <ins style="font-weight: bold; text-decoration: none;">experiments with </ins>wireless telegraph transmissions date back to the <ins style="font-weight: bold; text-decoration: none;">beginnings </ins>of the electric telegraph. The original <ins style="font-weight: bold; text-decoration: none;">electric </ins>telegraphs <ins style="font-weight: bold; text-decoration: none;">employed </ins>both sending and return wires, in order to provide a complete electrical circuit for the message transmission. However, in 1837, [[Carl August von Steinheil]] of Munich, Germany found that, by connecting the terminal end of the sending wire to metal plates buried in the ground, the return wire could be eliminated, and only a single wire <ins style="font-weight: bold; text-decoration: none;">was needed </ins>for telegraphing. At the time, a common belief was that<ins style="font-weight: bold; text-decoration: none;">, </ins>with <ins style="font-weight: bold; text-decoration: none;">the single wire </ins>configuration<ins style="font-weight: bold; text-decoration: none;">, </ins>the return current was now traveling through the ground back to the sending point in order to complete the <ins style="font-weight: bold; text-decoration: none;">electrical </ins>circuit. This turned out to be incorrect<ins style="font-weight: bold; text-decoration: none;">, as the transmitted current was actually being absorbed into the earth at the receiving point</ins>, but it did lead to speculation that it might be possible to someday also eliminate the sending wire, and telegraph through the ground without using any wires at all. Other attempts were made to send through bodies of water, for example, in order to span river crossings. Prominent experimenters along these lines included [[Samuel F. B. Morse]] in the United States and James Bowman Lindsay in Great Britain &mdash; in 1854 Lindsay demonstrated transmission across the Firth of Tay from Dundee to Woodhaven (now part of Newport-on-Tay), a distance of nearly 2 miles [3 kilometers].. However, because of the very high resistance to electrical currents, earth conductivity transmissions were found to be limited to only a few meters, and even the somewhat greater distances possible through water had little practical use.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Electrostatic Induction and Electromagnetic Induction===</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Electrostatic Induction and Electromagnetic Induction===</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Both electrostatic and electromagnetic induction were used to develop wireless telegraph systems <del style="font-weight: bold; text-decoration: none;">which </del>saw limited commercial application. In the United States, [[Thomas Edison]], in the mid-1880s, patented an electrostatic induction system he called "grasshopper telegraphy", which allowed telegraphic signals to jump the short distance between a running train and telegraph wires running parallel to the tracks. This system was successful technically but not economically, as there turned out to be little interest by train travelers in an on-board telegraph service. </div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Both electrostatic and electromagnetic induction were used to develop wireless telegraph systems <ins style="font-weight: bold; text-decoration: none;">that </ins>saw limited commercial application. In the United States, [[Thomas Edison]], in the mid-1880s, patented an electrostatic induction system he called "grasshopper telegraphy", which allowed telegraphic signals to jump the short distance between a running train and telegraph wires running parallel to the tracks. This system was successful technically but not economically, as there turned out to be little interest by train travelers in an on-board telegraph service. </div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The most successful creator of an electromagnetic induction system was [[William Preece]] in Great Britain, who began tests in 1882. By 1892 he was able to telegraph about 5 kilometers across the Bristol Channel. However, his induction system required extensive lengths of wire, many kilometers long, at both the sending and receiving ends, which made it impractical for use on ships or small islands, and the relatively short distances spanned meant it had few advantages over underwater cables.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The most successful creator of an electromagnetic induction system was [[William Preece]] in Great Britain, who began tests in 1882. By 1892 he was able to telegraph about 5 kilometers across the Bristol Channel. However, his induction system required extensive lengths of wire, many kilometers long, at both the sending and receiving ends, which made it impractical for use on ships or small islands, and the relatively short distances spanned meant it had few advantages over underwater cables.</div></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l20">Line 20:</td>
<td colspan="2" class="diff-lineno">Line 20:</td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Heinrich Hertz]] demonstrated the existence of electromagnetic radiation (radio waves) in a series of groundbreaking experiments in Germany during the 1880s. This led to work by numerous experimenters in using radio signals for wireless communication, initially with limited success. However, by 1897, [[Guglielmo Marconi]] had made a series of demonstrations in Great Britain which showed the practicality of using radio for signalling far greater distances than had been achieved by any other means, which led to an explosion of activity worldwide.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Heinrich Hertz]] demonstrated the existence of electromagnetic radiation (radio waves) in a series of groundbreaking experiments in Germany during the 1880s. This led to work by numerous experimenters in using radio signals for wireless communication, initially with limited success. However, by 1897, [[Guglielmo Marconi]] had made a series of demonstrations in Great Britain which showed the practicality of using radio for signalling far greater distances than had been achieved by any other means, which led to an explosion of activity worldwide.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>By the 1920s, there was a worldwide network of commercial and government radiotelegraphic stations, plus extensive use of radiotelegraphy by ships for both commercial purposes and passenger messages. The ultimate implementation of wireless telegraphy was [[teleprinter|telex]] using radio signals, which was developed in the 1940s, and was for many years the only reliable form of communication between many distant countries. The most advanced standard, [[ITU-T|CCITT]] [[R.44]], automated both routing and encoding of messages by [[short wave]] transmissions. <del style="font-weight: bold; text-decoration: none;">(See [[telegraphy]] for more information).</del></div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>By the 1920s, there was a worldwide network of commercial and government radiotelegraphic stations, plus extensive use of radiotelegraphy by ships for both commercial purposes and passenger messages. The ultimate implementation of wireless telegraphy was [[teleprinter|telex]] using radio signals, which was developed in the 1940s, and was for many years the only reliable form of communication between many distant countries. The most advanced standard, [[ITU-T|CCITT]] [[R.44]], automated both routing and encoding of messages by [[short wave]] transmissions. </div></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div> </div></td><td colspan="2" class="diff-side-added"></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">==Notes==</del></div></td><td colspan="2" class="diff-side-added"></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">{{reflist}}</del></div></td><td colspan="2" class="diff-side-added"></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br/></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Online resources==</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Online resources==</div></td></tr>
</table>imported>Thomas H. White