AM - Revision history

https://www.hfunderground.com/wiki/index.php?action=history&feed=atom&title=AM AM - Revision history 2026-10-21T22:18:58Z Revision history for this page on the wiki MediaWiki 1.16.5 https://www.hfunderground.com/wiki/index.php?title=AM&diff=16434&oldid=prev R4002 at 13:28, 13 August 2024 2024-08-13T13:28:35Z

<p></p> <table style="background-color: white; color:black;"> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr valign='top'> <td colspan='2' style="background-color: white; color:black;">← Older revision</td> <td colspan='2' style="background-color: white; color:black;">Revision as of 13:28, 13 August 2024</td> </tr><tr><td colspan="2" class="diff-lineno">Line 1:</td> <td colspan="2" class="diff-lineno">Line 1:</td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Image:Amplitude Modulation.jpg|right|thumb|300px|Amplitude Modulation]]'''Amplitude modulation (AM)''' is one of the modes frequently used by [[List_of_Pirate_Radio_Frequencies|pirates]] on [[HF]] and mediumwave. Often, pirates will use vintage [[amateur radio]] transmitters, such as those by E.F. Johnson (Valiant, Viking, Ranger), Globe and Heathkit. These transmitters are old, heavy and consume generous amounts of electricity, but are desirable because they can produce a relatively high fidelity, plate-modulated AM signal. At one time, these transmitters hardly had any value, but prices of vintage equipment have skyrocketed in the last decade. This may be one reason why AM is not quite as popular for pirate transmissions as it once was. Instead, many pirates prefer to use [[SSB]]. In addition, SSB is a more efficient mode. AM uses approximately 2/3 of its power on the carrier which contains no information but is needed to decode the signal. The remaining 1/3 of power is then used by two identical audio sidebands. SSB only transmits one audio sideband and the receiver generates the carrier, making it much more efficient. The downsides to SSB are that receivers are more complicated (and thus expensive) and most amateur transceivers limit the audio to have little bass and cut off high frequencies at 2.4 kHz. This audio filter is difficult to remove or disable and audio cannot be equalized to compensate for it. You must also be tuned to the exact frequency or the pitch will be wrong. AM transmitters are easy to make yourself and a homemade transmitter will have no audio cut off built in, allowing you to equalize the audio yourself before feeding it to the transmitter. Making an SSB transmitter yourself is nearly impossible.</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Image:Amplitude Modulation.jpg|right|thumb|300px|Amplitude Modulation]]'''Amplitude modulation (AM)''' is one of the modes frequently used by [[List_of_Pirate_Radio_Frequencies|pirates]] on [[HF]] and mediumwave. Often, pirates will use vintage [[amateur radio]] transmitters, such as those by E.F. Johnson (Valiant, Viking, Ranger), Globe and Heathkit. These transmitters are old, heavy and consume generous amounts of electricity, but are desirable because they can produce a relatively high fidelity, plate-modulated AM signal. At one time, these transmitters hardly had any value, but prices of vintage equipment have skyrocketed in the last decade. This may be one reason why AM is not quite as popular for pirate transmissions as it once was. Instead, many pirates prefer to use [[SSB]]. In addition, SSB is a more efficient mode. AM uses approximately 2/3 of its power on the carrier which contains no information but is needed to decode the signal. The remaining 1/3 of power is then used by two identical audio sidebands. SSB only transmits one audio sideband and the receiver generates the carrier, making it much more efficient. The downsides to SSB are that receivers are more complicated (and thus expensive) and most amateur transceivers limit the audio to have little bass and cut off high frequencies at 2.4 kHz. This audio filter is difficult to remove or disable and audio cannot be equalized to compensate for it. You must also be tuned to the exact frequency or the pitch will be wrong. AM transmitters are easy to make yourself and a homemade transmitter will have no audio cut off built in, allowing you to equalize the audio yourself before feeding it to the transmitter. Making an SSB transmitter yourself is nearly impossible.</div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div>AM is still extensively used on the medium wave broadcast band or the AM broadcast band, the shortwave [[Shortwave Broadcast Bands|broadcast bands]], for [[11_meter|11 meter band]] 27 MHz [[CB|CB radio]] (along with [[FM]] and SSB in many countries) as well as for [[VHF / UHF Radio|VHF]] (108-137 MHz) and [[VHF / UHF Radio|UHF]] (225-400 MHz) [[VHF_airband|aircraft band]] communications, [[VHF_airband#NAV_Navigation_VHF_VOR|aircraft]] navigation systems, some legacy HF marine radio communications systems and specialty [[CB#Australian_27_MHz_Marine_CB|marine radio]], fishery (fishing fleet) radio [[CB#Japanese_27MHz_Double_Side_Band_DSB_Marine_Fishery_Radio|communications]] [[Japanese_40MHz_DSB_Fishery_Radio|systems]] in Asia as well as [[HF_marine#MF_SSB_and_HF_SSB_marine_bands|older-generation]] "legacy" MF/HF marine radio (maritime mobile) networks based out of Russia, the CIS and former Soviet Union, including fishing trawlers, etc. in the 1.6 MHz to 4 MHz band (1600 kHz - 4000 kHz band).</div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>AM is still extensively used on the medium wave broadcast band or the AM broadcast band, the shortwave [[Shortwave Broadcast Bands|broadcast bands]], for [[11_meter|11 meter band]] 27 MHz [[CB|CB radio]] (along with [[FM]] and SSB in many countries) as well as for [[VHF / UHF Radio|VHF]] (108-137 MHz) and [[VHF / UHF Radio|UHF]] (225-400 MHz) [[VHF_airband|aircraft band]] communications, [[VHF_airband#NAV_Navigation_VHF_VOR|aircraft]] navigation systems, some legacy HF marine radio communications systems and specialty [[CB#Australian_27_MHz_Marine_CB|marine radio]], fishery (fishing fleet) radio [[CB#Japanese_27MHz_Double_Side_Band_DSB_Marine_Fishery_Radio|communications]] [[Japanese_40MHz_DSB_Fishery_Radio|systems]] in <ins class="diffchange diffchange-inline">[[CB#Thailand_27_MHz_Marine_Maritime_CB_Radio_Communications|</ins>Asia<ins class="diffchange diffchange-inline">]] </ins>as well as [[HF_marine#MF_SSB_and_HF_SSB_marine_bands|older-generation]] "legacy" MF/HF marine radio (maritime mobile) <ins class="diffchange diffchange-inline">[[Pescadores#Freebanders_on_HF|</ins>networks<ins class="diffchange diffchange-inline">]] </ins>based out of Russia, the CIS and former Soviet Union, including fishing trawlers, etc. in the 1.6 MHz to 4 MHz band (1600 kHz - 4000 kHz band<ins class="diffchange diffchange-inline">), with most activity focused around 3000 kHz (3.000 MHz</ins>). <ins class="diffchange diffchange-inline"> </ins></div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>AM mode is also known by its [[Emission Designator|emission]] designation A3 or A3E.  </div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>AM mode is also known by its [[Emission Designator|emission]] designation A3 or A3E.  </div></td></tr> </table>

R4002 https://www.hfunderground.com/wiki/index.php?title=AM&diff=16048&oldid=prev R4002 at 16:09, 6 March 2024 2024-03-06T16:09:55Z

<p></p> <table style="background-color: white; color:black;"> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr valign='top'> <td colspan='2' style="background-color: white; color:black;">← Older revision</td> <td colspan='2' style="background-color: white; color:black;">Revision as of 16:09, 6 March 2024</td> </tr><tr><td colspan="2" class="diff-lineno">Line 9:</td> <td colspan="2" class="diff-lineno">Line 9:</td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Category: Timtron]]</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Category: Timtron]]</div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Category: Amateur Radio]]</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Category: Amateur Radio]]</div></td></tr> <tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;">[[Category: Broadcasting]]</ins></div></td></tr> </table>

R4002 https://www.hfunderground.com/wiki/index.php?title=AM&diff=15979&oldid=prev R4002 at 14:35, 22 February 2024 2024-02-22T14:35:45Z

<p></p> <table style="background-color: white; color:black;"> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr valign='top'> <td colspan='2' style="background-color: white; color:black;">← Older revision</td> <td colspan='2' style="background-color: white; color:black;">Revision as of 14:35, 22 February 2024</td> </tr><tr><td colspan="2" class="diff-lineno">Line 1:</td> <td colspan="2" class="diff-lineno">Line 1:</td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Image:Amplitude Modulation.jpg|right|thumb|300px|Amplitude Modulation]]'''Amplitude modulation (AM)''' is one of the modes frequently used by [[List_of_Pirate_Radio_Frequencies|pirates]] on [[HF]] and mediumwave. Often, pirates will use vintage [[amateur radio]] transmitters, such as those by E.F. Johnson (Valiant, Viking, Ranger), Globe and Heathkit. These transmitters are old, heavy and consume generous amounts of electricity, but are desirable because they can produce a relatively high fidelity, plate-modulated AM signal. At one time, these transmitters hardly had any value, but prices of vintage equipment have skyrocketed in the last decade. This may be one reason why AM is not quite as popular for pirate transmissions as it once was. Instead, many pirates prefer to use [[SSB]]. In addition, SSB is a more efficient mode. AM uses approximately 2/3 of its power on the carrier which contains no information but is needed to decode the signal. The remaining 1/3 of power is then used by two identical audio sidebands. SSB only transmits one audio sideband and the receiver generates the carrier, making it much more efficient. The downsides to SSB are that receivers are more complicated (and thus expensive) and most amateur transceivers limit the audio to have little bass and cut off high frequencies at 2.4 kHz. This audio filter is difficult to remove or disable and audio cannot be equalized to compensate for it. You must also be tuned to the exact frequency or the pitch will be wrong. AM transmitters are easy to make yourself and a homemade transmitter will have no audio cut off built in, allowing you to equalize the audio yourself before feeding it to the transmitter. Making an SSB transmitter yourself is nearly impossible.</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Image:Amplitude Modulation.jpg|right|thumb|300px|Amplitude Modulation]]'''Amplitude modulation (AM)''' is one of the modes frequently used by [[List_of_Pirate_Radio_Frequencies|pirates]] on [[HF]] and mediumwave. Often, pirates will use vintage [[amateur radio]] transmitters, such as those by E.F. Johnson (Valiant, Viking, Ranger), Globe and Heathkit. These transmitters are old, heavy and consume generous amounts of electricity, but are desirable because they can produce a relatively high fidelity, plate-modulated AM signal. At one time, these transmitters hardly had any value, but prices of vintage equipment have skyrocketed in the last decade. This may be one reason why AM is not quite as popular for pirate transmissions as it once was. Instead, many pirates prefer to use [[SSB]]. In addition, SSB is a more efficient mode. AM uses approximately 2/3 of its power on the carrier which contains no information but is needed to decode the signal. The remaining 1/3 of power is then used by two identical audio sidebands. SSB only transmits one audio sideband and the receiver generates the carrier, making it much more efficient. The downsides to SSB are that receivers are more complicated (and thus expensive) and most amateur transceivers limit the audio to have little bass and cut off high frequencies at 2.4 kHz. This audio filter is difficult to remove or disable and audio cannot be equalized to compensate for it. You must also be tuned to the exact frequency or the pitch will be wrong. AM transmitters are easy to make yourself and a homemade transmitter will have no audio cut off built in, allowing you to equalize the audio yourself before feeding it to the transmitter. Making an SSB transmitter yourself is nearly impossible.</div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div>AM is still extensively used on the medium wave broadcast band or the AM broadcast band, the shortwave [[Shortwave Broadcast Bands|broadcast bands]], for [[11_meter|11 meter band]] 27 MHz [[CB|CB radio]] (along with [[FM]] and SSB in many countries) as well as for [[VHF / UHF Radio|VHF]] (108-137 MHz) and [[VHF / UHF Radio|UHF]] (225-400 MHz) [[VHF_airband|aircraft band]] communications, [[VHF_airband#NAV_Navigation_VHF_VOR|aircraft]] navigation systems, some legacy HF marine radio communications systems and specialty [[CB#Australian_27_MHz_Marine_CB|marine radio]], fishery (fishing fleet) radio [[CB#Japanese_27MHz_Double_Side_Band_DSB_Marine_Fishery_Radio|communications systems]] in Asia as well as [[HF_marine#MF_SSB_and_HF_SSB_marine_bands|older-generation]] "legacy" MF/HF marine radio (maritime mobile) networks based out of Russia, the CIS and former Soviet Union, including fishing trawlers, etc. in the 1.6 MHz to 4 MHz band (1600 kHz - 4000 kHz band).</div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>AM is still extensively used on the medium wave broadcast band or the AM broadcast band, the shortwave [[Shortwave Broadcast Bands|broadcast bands]], for [[11_meter|11 meter band]] 27 MHz [[CB|CB radio]] (along with [[FM]] and SSB in many countries) as well as for [[VHF / UHF Radio|VHF]] (108-137 MHz) and [[VHF / UHF Radio|UHF]] (225-400 MHz) [[VHF_airband|aircraft band]] communications, [[VHF_airband#NAV_Navigation_VHF_VOR|aircraft]] navigation systems, some legacy HF marine radio communications systems and specialty [[CB#Australian_27_MHz_Marine_CB|marine radio]], fishery (fishing fleet) radio [[CB#Japanese_27MHz_Double_Side_Band_DSB_Marine_Fishery_Radio|communications<ins class="diffchange diffchange-inline">]] [[Japanese_40MHz_DSB_Fishery_Radio|</ins>systems]] in Asia as well as [[HF_marine#MF_SSB_and_HF_SSB_marine_bands|older-generation]] "legacy" MF/HF marine radio (maritime mobile) networks based out of Russia, the CIS and former Soviet Union, including fishing trawlers, etc. in the 1.6 MHz to 4 MHz band (1600 kHz - 4000 kHz band).</div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>AM mode is also known by its [[Emission Designator|emission]] designation A3 or A3E.  </div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>AM mode is also known by its [[Emission Designator|emission]] designation A3 or A3E.  </div></td></tr> </table>

R4002 https://www.hfunderground.com/wiki/index.php?title=AM&diff=15962&oldid=prev R4002 at 14:23, 22 February 2024 2024-02-22T14:23:24Z

<p></p> <table style="background-color: white; color:black;"> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr valign='top'> <td colspan='2' style="background-color: white; color:black;">← Older revision</td> <td colspan='2' style="background-color: white; color:black;">Revision as of 14:23, 22 February 2024</td> </tr><tr><td colspan="2" class="diff-lineno">Line 1:</td> <td colspan="2" class="diff-lineno">Line 1:</td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Image:Amplitude Modulation.jpg|right|thumb|300px|Amplitude Modulation]]'''Amplitude modulation (AM)''' is one of the modes frequently used by [[List_of_Pirate_Radio_Frequencies|pirates]] on [[HF]] and mediumwave. Often, pirates will use vintage [[amateur radio]] transmitters, such as those by E.F. Johnson (Valiant, Viking, Ranger), Globe and Heathkit. These transmitters are old, heavy and consume generous amounts of electricity, but are desirable because they can produce a relatively high fidelity, plate-modulated AM signal. At one time, these transmitters hardly had any value, but prices of vintage equipment have skyrocketed in the last decade. This may be one reason why AM is not quite as popular for pirate transmissions as it once was. Instead, many pirates prefer to use [[SSB]]. In addition, SSB is a more efficient mode. AM uses approximately 2/3 of its power on the carrier which contains no information but is needed to decode the signal. The remaining 1/3 of power is then used by two identical audio sidebands. SSB only transmits one audio sideband and the receiver generates the carrier, making it much more efficient. The downsides to SSB are that receivers are more complicated (and thus expensive) and most amateur transceivers limit the audio to have little bass and cut off high frequencies at 2.4 kHz. This audio filter is difficult to remove or disable and audio cannot be equalized to compensate for it. You must also be tuned to the exact frequency or the pitch will be wrong. AM transmitters are easy to make yourself and a homemade transmitter will have no audio cut off built in, allowing you to equalize the audio yourself before feeding it to the transmitter. Making an SSB transmitter yourself is nearly impossible.</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Image:Amplitude Modulation.jpg|right|thumb|300px|Amplitude Modulation]]'''Amplitude modulation (AM)''' is one of the modes frequently used by [[List_of_Pirate_Radio_Frequencies|pirates]] on [[HF]] and mediumwave. Often, pirates will use vintage [[amateur radio]] transmitters, such as those by E.F. Johnson (Valiant, Viking, Ranger), Globe and Heathkit. These transmitters are old, heavy and consume generous amounts of electricity, but are desirable because they can produce a relatively high fidelity, plate-modulated AM signal. At one time, these transmitters hardly had any value, but prices of vintage equipment have skyrocketed in the last decade. This may be one reason why AM is not quite as popular for pirate transmissions as it once was. Instead, many pirates prefer to use [[SSB]]. In addition, SSB is a more efficient mode. AM uses approximately 2/3 of its power on the carrier which contains no information but is needed to decode the signal. The remaining 1/3 of power is then used by two identical audio sidebands. SSB only transmits one audio sideband and the receiver generates the carrier, making it much more efficient. The downsides to SSB are that receivers are more complicated (and thus expensive) and most amateur transceivers limit the audio to have little bass and cut off high frequencies at 2.4 kHz. This audio filter is difficult to remove or disable and audio cannot be equalized to compensate for it. You must also be tuned to the exact frequency or the pitch will be wrong. AM transmitters are easy to make yourself and a homemade transmitter will have no audio cut off built in, allowing you to equalize the audio yourself before feeding it to the transmitter. Making an SSB transmitter yourself is nearly impossible.</div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div>AM is still extensively used on the medium wave broadcast band or the AM broadcast band, the shortwave [[Shortwave Broadcast Bands|broadcast bands]], for [[11_meter|11 meter band]] 27 MHz [[CB|CB radio]] (along with [[FM]] and SSB in many countries) as well as for [[VHF / UHF Radio|VHF]] (108-137 MHz) and [[VHF / UHF Radio|UHF]] (225-400 MHz) [[VHF_airband|aircraft band]] communications, [[VHF_airband#NAV_Navigation_VHF_VOR|aircraft]] navigation systems, some legacy HF marine radio communications systems and specialty [[CB#Australian_27_MHz_Marine_CB|marine radio]], fishery (fishing fleet) radio [[CB#Japanese_27MHz_Double_Side_Band_DSB_Marine_Fishery_Radio|communications systems]] in Asia as well as older-generation "legacy" MF/HF marine radio (maritime mobile) networks in the 1.6 MHz to 4 MHz band (1600 kHz - 4000 kHz band).</div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>AM is still extensively used on the medium wave broadcast band or the AM broadcast band, the shortwave [[Shortwave Broadcast Bands|broadcast bands]], for [[11_meter|11 meter band]] 27 MHz [[CB|CB radio]] (along with [[FM]] and SSB in many countries) as well as for [[VHF / UHF Radio|VHF]] (108-137 MHz) and [[VHF / UHF Radio|UHF]] (225-400 MHz) [[VHF_airband|aircraft band]] communications, [[VHF_airband#NAV_Navigation_VHF_VOR|aircraft]] navigation systems, some legacy HF marine radio communications systems and specialty [[CB#Australian_27_MHz_Marine_CB|marine radio]], fishery (fishing fleet) radio [[CB#Japanese_27MHz_Double_Side_Band_DSB_Marine_Fishery_Radio|communications systems]] in Asia as well as <ins class="diffchange diffchange-inline">[[HF_marine#MF_SSB_and_HF_SSB_marine_bands|</ins>older-generation<ins class="diffchange diffchange-inline">]] </ins>"legacy" MF/HF marine radio (maritime mobile) networks <ins class="diffchange diffchange-inline">based out of Russia, the CIS and former Soviet Union, including fishing trawlers, etc. </ins>in the 1.6 MHz to 4 MHz band (1600 kHz - 4000 kHz band).</div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>AM mode is also known by its [[Emission Designator|emission]] designation A3 or A3E.  </div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>AM mode is also known by its [[Emission Designator|emission]] designation A3 or A3E.  </div></td></tr> </table>

R4002 https://www.hfunderground.com/wiki/index.php?title=AM&diff=15960&oldid=prev R4002 at 14:21, 22 February 2024 2024-02-22T14:21:43Z

<p></p> <table style="background-color: white; color:black;"> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr valign='top'> <td colspan='2' style="background-color: white; color:black;">← Older revision</td> <td colspan='2' style="background-color: white; color:black;">Revision as of 14:21, 22 February 2024</td> </tr><tr><td colspan="2" class="diff-lineno">Line 1:</td> <td colspan="2" class="diff-lineno">Line 1:</td></tr> <tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div>[[Image:Amplitude Modulation.jpg|right|thumb|300px|Amplitude Modulation]]'''Amplitude modulation (AM)''' is one of the modes frequently used by pirates on [[HF]] and mediumwave. Often, pirates will use vintage [[amateur radio]] transmitters, such as those by E.F. Johnson (Valiant, Viking, Ranger), Globe and Heathkit. These transmitters are old, heavy and consume generous amounts of electricity, but are desirable because they can produce a relatively high fidelity, plate-modulated AM signal. At one time, these transmitters hardly had any value, but prices of vintage equipment have skyrocketed in the last decade. This may be one reason why AM is not quite as popular for pirate transmissions as it once was. Instead, many pirates prefer to use [[SSB]]. In addition, SSB is a more efficient mode. AM uses approximately 2/3 of its power on the carrier which contains no information but is needed to decode the signal. The remaining 1/3 of power is then used by two identical audio sidebands. SSB only transmits one audio sideband and the receiver generates the carrier, making it much more efficient. The downsides to SSB are that receivers are more complicated (and thus expensive) and most amateur transceivers limit the audio to have little bass and cut off high frequencies at 2.4 kHz. This audio filter is difficult to remove or disable and audio cannot be equalized to compensate for it. You must also be tuned to the exact frequency or the pitch will be wrong. AM transmitters are easy to make yourself and a homemade transmitter will have no audio cut off built in, allowing you to equalize the audio yourself before feeding it to the transmitter. Making an SSB transmitter yourself is nearly impossible.</div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>[[Image:Amplitude Modulation.jpg|right|thumb|300px|Amplitude Modulation]]'''Amplitude modulation (AM)''' is one of the modes frequently used by <ins class="diffchange diffchange-inline">[[List_of_Pirate_Radio_Frequencies|</ins>pirates<ins class="diffchange diffchange-inline">]] </ins>on [[HF]] and mediumwave. Often, pirates will use vintage [[amateur radio]] transmitters, such as those by E.F. Johnson (Valiant, Viking, Ranger), Globe and Heathkit. These transmitters are old, heavy and consume generous amounts of electricity, but are desirable because they can produce a relatively high fidelity, plate-modulated AM signal. At one time, these transmitters hardly had any value, but prices of vintage equipment have skyrocketed in the last decade. This may be one reason why AM is not quite as popular for pirate transmissions as it once was. Instead, many pirates prefer to use [[SSB]]. In addition, SSB is a more efficient mode. AM uses approximately 2/3 of its power on the carrier which contains no information but is needed to decode the signal. The remaining 1/3 of power is then used by two identical audio sidebands. SSB only transmits one audio sideband and the receiver generates the carrier, making it much more efficient. The downsides to SSB are that receivers are more complicated (and thus expensive) and most amateur transceivers limit the audio to have little bass and cut off high frequencies at 2.4 kHz. This audio filter is difficult to remove or disable and audio cannot be equalized to compensate for it. You must also be tuned to the exact frequency or the pitch will be wrong. AM transmitters are easy to make yourself and a homemade transmitter will have no audio cut off built in, allowing you to equalize the audio yourself before feeding it to the transmitter. Making an SSB transmitter yourself is nearly impossible.</div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div>AM is still extensively used on the medium wave broadcast band or the AM broadcast band, the shortwave [[Shortwave Broadcast Bands|broadcast bands]], for 11 meter band 27 MHz [[CB|CB radio]] (along with [[FM]] and SSB in many countries) as well as for [[VHF / UHF Radio|VHF]] (108-137 MHz) and [[VHF / UHF Radio|UHF]] (225-400 MHz) [[VHF_airband|aircraft band]] communications, [[VHF_airband#NAV_Navigation_VHF_VOR|aircraft]] navigation systems, some legacy HF marine radio communications systems and <del class="diffchange diffchange-inline">speciality </del>[[CB#Australian_27_MHz_Marine_CB|marine radio]] <del class="diffchange diffchange-inline">and </del>fishery (fishing fleet) radio [[CB#Japanese_27MHz_Double_Side_Band_DSB_Marine_Fishery_Radio|communications systems]] in Asia.</div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>AM is still extensively used on the medium wave broadcast band or the AM broadcast band, the shortwave [[Shortwave Broadcast Bands|broadcast bands]], for <ins class="diffchange diffchange-inline">[[11_meter|</ins>11 meter band<ins class="diffchange diffchange-inline">]] </ins>27 MHz [[CB|CB radio]] (along with [[FM]] and SSB in many countries) as well as for [[VHF / UHF Radio|VHF]] (108-137 MHz) and [[VHF / UHF Radio|UHF]] (225-400 MHz) [[VHF_airband|aircraft band]] communications, [[VHF_airband#NAV_Navigation_VHF_VOR|aircraft]] navigation systems, some legacy HF marine radio communications systems and <ins class="diffchange diffchange-inline">specialty </ins>[[CB#Australian_27_MHz_Marine_CB|marine radio]]<ins class="diffchange diffchange-inline">, </ins>fishery (fishing fleet) radio [[CB#Japanese_27MHz_Double_Side_Band_DSB_Marine_Fishery_Radio|communications systems]] in Asia <ins class="diffchange diffchange-inline">as well as older-generation "legacy" MF/HF marine radio (maritime mobile) networks in the 1.6 MHz to 4 MHz band (1600 kHz - 4000 kHz band)</ins>.</div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>AM mode is also known by its [[Emission Designator|emission]] designation A3 or A3E.  </div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>AM mode is also known by its [[Emission Designator|emission]] designation A3 or A3E.  </div></td></tr> </table>

R4002 https://www.hfunderground.com/wiki/index.php?title=AM&diff=14531&oldid=prev R4002 at 10:51, 13 October 2022 2022-10-13T10:51:43Z

<p></p> <table style="background-color: white; color:black;"> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr valign='top'> <td colspan='2' style="background-color: white; color:black;">← Older revision</td> <td colspan='2' style="background-color: white; color:black;">Revision as of 10:51, 13 October 2022</td> </tr><tr><td colspan="2" class="diff-lineno">Line 1:</td> <td colspan="2" class="diff-lineno">Line 1:</td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Image:Amplitude Modulation.jpg|right|thumb|300px|Amplitude Modulation]]'''Amplitude modulation (AM)''' is one of the modes frequently used by pirates on [[HF]] and mediumwave. Often, pirates will use vintage [[amateur radio]] transmitters, such as those by E.F. Johnson (Valiant, Viking, Ranger), Globe and Heathkit. These transmitters are old, heavy and consume generous amounts of electricity, but are desirable because they can produce a relatively high fidelity, plate-modulated AM signal. At one time, these transmitters hardly had any value, but prices of vintage equipment have skyrocketed in the last decade. This may be one reason why AM is not quite as popular for pirate transmissions as it once was. Instead, many pirates prefer to use [[SSB]]. In addition, SSB is a more efficient mode. AM uses approximately 2/3 of its power on the carrier which contains no information but is needed to decode the signal. The remaining 1/3 of power is then used by two identical audio sidebands. SSB only transmits one audio sideband and the receiver generates the carrier, making it much more efficient. The downsides to SSB are that receivers are more complicated (and thus expensive) and most amateur transceivers limit the audio to have little bass and cut off high frequencies at 2.4 kHz. This audio filter is difficult to remove or disable and audio cannot be equalized to compensate for it. You must also be tuned to the exact frequency or the pitch will be wrong. AM transmitters are easy to make yourself and a homemade transmitter will have no audio cut off built in, allowing you to equalize the audio yourself before feeding it to the transmitter. Making an SSB transmitter yourself is nearly impossible.</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Image:Amplitude Modulation.jpg|right|thumb|300px|Amplitude Modulation]]'''Amplitude modulation (AM)''' is one of the modes frequently used by pirates on [[HF]] and mediumwave. Often, pirates will use vintage [[amateur radio]] transmitters, such as those by E.F. Johnson (Valiant, Viking, Ranger), Globe and Heathkit. These transmitters are old, heavy and consume generous amounts of electricity, but are desirable because they can produce a relatively high fidelity, plate-modulated AM signal. At one time, these transmitters hardly had any value, but prices of vintage equipment have skyrocketed in the last decade. This may be one reason why AM is not quite as popular for pirate transmissions as it once was. Instead, many pirates prefer to use [[SSB]]. In addition, SSB is a more efficient mode. AM uses approximately 2/3 of its power on the carrier which contains no information but is needed to decode the signal. The remaining 1/3 of power is then used by two identical audio sidebands. SSB only transmits one audio sideband and the receiver generates the carrier, making it much more efficient. The downsides to SSB are that receivers are more complicated (and thus expensive) and most amateur transceivers limit the audio to have little bass and cut off high frequencies at 2.4 kHz. This audio filter is difficult to remove or disable and audio cannot be equalized to compensate for it. You must also be tuned to the exact frequency or the pitch will be wrong. AM transmitters are easy to make yourself and a homemade transmitter will have no audio cut off built in, allowing you to equalize the audio yourself before feeding it to the transmitter. Making an SSB transmitter yourself is nearly impossible.</div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div>AM is still extensively used on the medium wave broadcast band or the AM broadcast band, the shortwave [[Shortwave Broadcast Bands|broadcast bands]], for 11 meter 27 MHz<del class="diffchange diffchange-inline">, </del>[[CB|CB radio]] (along with [[FM]] and SSB in many countries) as well as for [[VHF / UHF Radio|VHF]] (108-137 MHz) and [[VHF / UHF Radio|UHF]] (225-400 MHz) [[VHF_airband|aircraft band]] communications, [[VHF_airband#NAV_Navigation_VHF_VOR|aircraft]] navigation systems, some legacy HF marine radio communications systems and speciality [[CB#Australian_27_MHz_Marine_CB|marine radio]] and fishery (fishing fleet) radio [[CB#Japanese_27MHz_Double_Side_Band_DSB_Marine_Fishery_Radio|communications systems]] in Asia.</div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>AM is still extensively used on the medium wave broadcast band or the AM broadcast band, the shortwave [[Shortwave Broadcast Bands|broadcast bands]], for 11 meter <ins class="diffchange diffchange-inline">band </ins>27 MHz [[CB|CB radio]] (along with [[FM]] and SSB in many countries) as well as for [[VHF / UHF Radio|VHF]] (108-137 MHz) and [[VHF / UHF Radio|UHF]] (225-400 MHz) [[VHF_airband|aircraft band]] communications, [[VHF_airband#NAV_Navigation_VHF_VOR|aircraft]] navigation systems, some legacy HF marine radio communications systems and speciality [[CB#Australian_27_MHz_Marine_CB|marine radio]] and fishery (fishing fleet) radio [[CB#Japanese_27MHz_Double_Side_Band_DSB_Marine_Fishery_Radio|communications systems]] in Asia.</div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>AM mode is also known by its [[Emission Designator|emission]] designation A3 or A3E.  </div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>AM mode is also known by its [[Emission Designator|emission]] designation A3 or A3E.  </div></td></tr> </table>

R4002 https://www.hfunderground.com/wiki/index.php?title=AM&diff=14530&oldid=prev R4002 at 10:51, 13 October 2022 2022-10-13T10:51:01Z

<p></p> <table style="background-color: white; color:black;"> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr valign='top'> <td colspan='2' style="background-color: white; color:black;">← Older revision</td> <td colspan='2' style="background-color: white; color:black;">Revision as of 10:51, 13 October 2022</td> </tr><tr><td colspan="2" class="diff-lineno">Line 1:</td> <td colspan="2" class="diff-lineno">Line 1:</td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Image:Amplitude Modulation.jpg|right|thumb|300px|Amplitude Modulation]]'''Amplitude modulation (AM)''' is one of the modes frequently used by pirates on [[HF]] and mediumwave. Often, pirates will use vintage [[amateur radio]] transmitters, such as those by E.F. Johnson (Valiant, Viking, Ranger), Globe and Heathkit. These transmitters are old, heavy and consume generous amounts of electricity, but are desirable because they can produce a relatively high fidelity, plate-modulated AM signal. At one time, these transmitters hardly had any value, but prices of vintage equipment have skyrocketed in the last decade. This may be one reason why AM is not quite as popular for pirate transmissions as it once was. Instead, many pirates prefer to use [[SSB]]. In addition, SSB is a more efficient mode. AM uses approximately 2/3 of its power on the carrier which contains no information but is needed to decode the signal. The remaining 1/3 of power is then used by two identical audio sidebands. SSB only transmits one audio sideband and the receiver generates the carrier, making it much more efficient. The downsides to SSB are that receivers are more complicated (and thus expensive) and most amateur transceivers limit the audio to have little bass and cut off high frequencies at 2.4 kHz. This audio filter is difficult to remove or disable and audio cannot be equalized to compensate for it. You must also be tuned to the exact frequency or the pitch will be wrong. AM transmitters are easy to make yourself and a homemade transmitter will have no audio cut off built in, allowing you to equalize the audio yourself before feeding it to the transmitter. Making an SSB transmitter yourself is nearly impossible.</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Image:Amplitude Modulation.jpg|right|thumb|300px|Amplitude Modulation]]'''Amplitude modulation (AM)''' is one of the modes frequently used by pirates on [[HF]] and mediumwave. Often, pirates will use vintage [[amateur radio]] transmitters, such as those by E.F. Johnson (Valiant, Viking, Ranger), Globe and Heathkit. These transmitters are old, heavy and consume generous amounts of electricity, but are desirable because they can produce a relatively high fidelity, plate-modulated AM signal. At one time, these transmitters hardly had any value, but prices of vintage equipment have skyrocketed in the last decade. This may be one reason why AM is not quite as popular for pirate transmissions as it once was. Instead, many pirates prefer to use [[SSB]]. In addition, SSB is a more efficient mode. AM uses approximately 2/3 of its power on the carrier which contains no information but is needed to decode the signal. The remaining 1/3 of power is then used by two identical audio sidebands. SSB only transmits one audio sideband and the receiver generates the carrier, making it much more efficient. The downsides to SSB are that receivers are more complicated (and thus expensive) and most amateur transceivers limit the audio to have little bass and cut off high frequencies at 2.4 kHz. This audio filter is difficult to remove or disable and audio cannot be equalized to compensate for it. You must also be tuned to the exact frequency or the pitch will be wrong. AM transmitters are easy to make yourself and a homemade transmitter will have no audio cut off built in, allowing you to equalize the audio yourself before feeding it to the transmitter. Making an SSB transmitter yourself is nearly impossible.</div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div>AM is still extensively used on the medium wave broadcast band or the AM broadcast band, the shortwave [[Shortwave Broadcast Bands|broadcast bands]], for 11 meter 27 MHz, [[CB|CB radio]] (along with [[FM]] and SSB in many countries) as well as for [[VHF / UHF Radio|VHF]] (108-137 MHz) and [[VHF / UHF Radio|UHF]] (225-400 MHz) [[VHF_airband|aircraft band]] communications, [[VHF_airband#NAV_Navigation_VHF_VOR|aircraft]] navigation systems, some legacy HF marine radio communications systems and speciality [[CB#Australian_27_MHz_Marine_CB|marine radio]] and fishery (fishing fleet) systems.</div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>AM is still extensively used on the medium wave broadcast band or the AM broadcast band, the shortwave [[Shortwave Broadcast Bands|broadcast bands]], for 11 meter 27 MHz, [[CB|CB radio]] (along with [[FM]] and SSB in many countries) as well as for [[VHF / UHF Radio|VHF]] (108-137 MHz) and [[VHF / UHF Radio|UHF]] (225-400 MHz) [[VHF_airband|aircraft band]] communications, [[VHF_airband#NAV_Navigation_VHF_VOR|aircraft]] navigation systems, some legacy HF marine radio communications systems and speciality [[CB#Australian_27_MHz_Marine_CB|marine radio]] and fishery (fishing fleet) <ins class="diffchange diffchange-inline">radio [[CB#Japanese_27MHz_Double_Side_Band_DSB_Marine_Fishery_Radio|communications </ins>systems<ins class="diffchange diffchange-inline">]] in Asia</ins>.</div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>AM mode is also known by its [[Emission Designator|emission]] designation A3 or A3E.  </div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>AM mode is also known by its [[Emission Designator|emission]] designation A3 or A3E.  </div></td></tr> </table>

R4002 https://www.hfunderground.com/wiki/index.php?title=AM&diff=14529&oldid=prev R4002 at 10:48, 13 October 2022 2022-10-13T10:48:44Z

<p></p> <table style="background-color: white; color:black;"> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr valign='top'> <td colspan='2' style="background-color: white; color:black;">← Older revision</td> <td colspan='2' style="background-color: white; color:black;">Revision as of 10:48, 13 October 2022</td> </tr><tr><td colspan="2" class="diff-lineno">Line 1:</td> <td colspan="2" class="diff-lineno">Line 1:</td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Image:Amplitude Modulation.jpg|right|thumb|300px|Amplitude Modulation]]'''Amplitude modulation (AM)''' is one of the modes frequently used by pirates on [[HF]] and mediumwave. Often, pirates will use vintage [[amateur radio]] transmitters, such as those by E.F. Johnson (Valiant, Viking, Ranger), Globe and Heathkit. These transmitters are old, heavy and consume generous amounts of electricity, but are desirable because they can produce a relatively high fidelity, plate-modulated AM signal. At one time, these transmitters hardly had any value, but prices of vintage equipment have skyrocketed in the last decade. This may be one reason why AM is not quite as popular for pirate transmissions as it once was. Instead, many pirates prefer to use [[SSB]]. In addition, SSB is a more efficient mode. AM uses approximately 2/3 of its power on the carrier which contains no information but is needed to decode the signal. The remaining 1/3 of power is then used by two identical audio sidebands. SSB only transmits one audio sideband and the receiver generates the carrier, making it much more efficient. The downsides to SSB are that receivers are more complicated (and thus expensive) and most amateur transceivers limit the audio to have little bass and cut off high frequencies at 2.4 kHz. This audio filter is difficult to remove or disable and audio cannot be equalized to compensate for it. You must also be tuned to the exact frequency or the pitch will be wrong. AM transmitters are easy to make yourself and a homemade transmitter will have no audio cut off built in, allowing you to equalize the audio yourself before feeding it to the transmitter. Making an SSB transmitter yourself is nearly impossible.</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Image:Amplitude Modulation.jpg|right|thumb|300px|Amplitude Modulation]]'''Amplitude modulation (AM)''' is one of the modes frequently used by pirates on [[HF]] and mediumwave. Often, pirates will use vintage [[amateur radio]] transmitters, such as those by E.F. Johnson (Valiant, Viking, Ranger), Globe and Heathkit. These transmitters are old, heavy and consume generous amounts of electricity, but are desirable because they can produce a relatively high fidelity, plate-modulated AM signal. At one time, these transmitters hardly had any value, but prices of vintage equipment have skyrocketed in the last decade. This may be one reason why AM is not quite as popular for pirate transmissions as it once was. Instead, many pirates prefer to use [[SSB]]. In addition, SSB is a more efficient mode. AM uses approximately 2/3 of its power on the carrier which contains no information but is needed to decode the signal. The remaining 1/3 of power is then used by two identical audio sidebands. SSB only transmits one audio sideband and the receiver generates the carrier, making it much more efficient. The downsides to SSB are that receivers are more complicated (and thus expensive) and most amateur transceivers limit the audio to have little bass and cut off high frequencies at 2.4 kHz. This audio filter is difficult to remove or disable and audio cannot be equalized to compensate for it. You must also be tuned to the exact frequency or the pitch will be wrong. AM transmitters are easy to make yourself and a homemade transmitter will have no audio cut off built in, allowing you to equalize the audio yourself before feeding it to the transmitter. Making an SSB transmitter yourself is nearly impossible.</div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div>AM is still extensively used on the medium wave broadcast band or the AM broadcast band, the shortwave [[Shortwave Broadcast Bands|broadcast bands]], for 11 meter 27 MHz, [[CB|CB radio]] (along with [[FM]] and SSB in many countries) as well as for [[VHF / UHF Radio|VHF]] (108-137 MHz) and [[VHF / UHF Radio|UHF]] (225-400 MHz) [[VHF_airband|aircraft band]] communications, [[<del class="diffchange diffchange-inline">https://www.hfunderground.com/wiki/index.php/</del>VHF_airband#NAV_Navigation_VHF_VOR|aircraft]] navigation systems, some legacy HF marine radio communications systems and speciality [[CB#Australian_27_MHz_Marine_CB|marine radio]] and fishery (fishing fleet) systems.</div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>AM is still extensively used on the medium wave broadcast band or the AM broadcast band, the shortwave [[Shortwave Broadcast Bands|broadcast bands]], for 11 meter 27 MHz, [[CB|CB radio]] (along with [[FM]] and SSB in many countries) as well as for [[VHF / UHF Radio|VHF]] (108-137 MHz) and [[VHF / UHF Radio|UHF]] (225-400 MHz) [[VHF_airband|aircraft band]] communications, [[VHF_airband#NAV_Navigation_VHF_VOR|aircraft]] navigation systems, some legacy HF marine radio communications systems and speciality [[CB#Australian_27_MHz_Marine_CB|marine radio]] and fishery (fishing fleet) systems.</div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>AM mode is also known by its [[Emission Designator|emission]] designation A3 or A3E.  </div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>AM mode is also known by its [[Emission Designator|emission]] designation A3 or A3E.  </div></td></tr> </table>

R4002 https://www.hfunderground.com/wiki/index.php?title=AM&diff=14528&oldid=prev R4002 at 10:48, 13 October 2022 2022-10-13T10:48:17Z

<p></p> <table style="background-color: white; color:black;"> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr valign='top'> <td colspan='2' style="background-color: white; color:black;">← Older revision</td> <td colspan='2' style="background-color: white; color:black;">Revision as of 10:48, 13 October 2022</td> </tr><tr><td colspan="2" class="diff-lineno">Line 1:</td> <td colspan="2" class="diff-lineno">Line 1:</td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Image:Amplitude Modulation.jpg|right|thumb|300px|Amplitude Modulation]]'''Amplitude modulation (AM)''' is one of the modes frequently used by pirates on [[HF]] and mediumwave. Often, pirates will use vintage [[amateur radio]] transmitters, such as those by E.F. Johnson (Valiant, Viking, Ranger), Globe and Heathkit. These transmitters are old, heavy and consume generous amounts of electricity, but are desirable because they can produce a relatively high fidelity, plate-modulated AM signal. At one time, these transmitters hardly had any value, but prices of vintage equipment have skyrocketed in the last decade. This may be one reason why AM is not quite as popular for pirate transmissions as it once was. Instead, many pirates prefer to use [[SSB]]. In addition, SSB is a more efficient mode. AM uses approximately 2/3 of its power on the carrier which contains no information but is needed to decode the signal. The remaining 1/3 of power is then used by two identical audio sidebands. SSB only transmits one audio sideband and the receiver generates the carrier, making it much more efficient. The downsides to SSB are that receivers are more complicated (and thus expensive) and most amateur transceivers limit the audio to have little bass and cut off high frequencies at 2.4 kHz. This audio filter is difficult to remove or disable and audio cannot be equalized to compensate for it. You must also be tuned to the exact frequency or the pitch will be wrong. AM transmitters are easy to make yourself and a homemade transmitter will have no audio cut off built in, allowing you to equalize the audio yourself before feeding it to the transmitter. Making an SSB transmitter yourself is nearly impossible.</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Image:Amplitude Modulation.jpg|right|thumb|300px|Amplitude Modulation]]'''Amplitude modulation (AM)''' is one of the modes frequently used by pirates on [[HF]] and mediumwave. Often, pirates will use vintage [[amateur radio]] transmitters, such as those by E.F. Johnson (Valiant, Viking, Ranger), Globe and Heathkit. These transmitters are old, heavy and consume generous amounts of electricity, but are desirable because they can produce a relatively high fidelity, plate-modulated AM signal. At one time, these transmitters hardly had any value, but prices of vintage equipment have skyrocketed in the last decade. This may be one reason why AM is not quite as popular for pirate transmissions as it once was. Instead, many pirates prefer to use [[SSB]]. In addition, SSB is a more efficient mode. AM uses approximately 2/3 of its power on the carrier which contains no information but is needed to decode the signal. The remaining 1/3 of power is then used by two identical audio sidebands. SSB only transmits one audio sideband and the receiver generates the carrier, making it much more efficient. The downsides to SSB are that receivers are more complicated (and thus expensive) and most amateur transceivers limit the audio to have little bass and cut off high frequencies at 2.4 kHz. This audio filter is difficult to remove or disable and audio cannot be equalized to compensate for it. You must also be tuned to the exact frequency or the pitch will be wrong. AM transmitters are easy to make yourself and a homemade transmitter will have no audio cut off built in, allowing you to equalize the audio yourself before feeding it to the transmitter. Making an SSB transmitter yourself is nearly impossible.</div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div>AM is still extensively used on the medium wave broadcast band or the AM broadcast band, the shortwave [[Shortwave Broadcast Bands|broadcast bands]], for 11 meter 27 MHz, [[CB|CB radio]] (along with [[FM]] and SSB in many countries) as well as for [[VHF / UHF Radio|VHF]] (108-137 MHz) and [[VHF / UHF Radio|UHF]] (225-400 MHz) [[VHF_airband|aircraft band]] communications, [[https://www.hfunderground.com/wiki/index.php/VHF_airband#NAV_Navigation_VHF_VOR|aircraft]] navigation systems, some legacy HF marine radio communications systems and speciality marine radio systems.</div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>AM is still extensively used on the medium wave broadcast band or the AM broadcast band, the shortwave [[Shortwave Broadcast Bands|broadcast bands]], for 11 meter 27 MHz, [[CB|CB radio]] (along with [[FM]] and SSB in many countries) as well as for [[VHF / UHF Radio|VHF]] (108-137 MHz) and [[VHF / UHF Radio|UHF]] (225-400 MHz) [[VHF_airband|aircraft band]] communications, [[https://www.hfunderground.com/wiki/index.php/VHF_airband#NAV_Navigation_VHF_VOR|aircraft]] navigation systems, some legacy HF marine radio communications systems and speciality <ins class="diffchange diffchange-inline">[[CB#Australian_27_MHz_Marine_CB|</ins>marine radio<ins class="diffchange diffchange-inline">]] and fishery (fishing fleet) </ins>systems.</div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>AM mode is also known by its [[Emission Designator|emission]] designation A3 or A3E.  </div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>AM mode is also known by its [[Emission Designator|emission]] designation A3 or A3E.  </div></td></tr> </table>

R4002 https://www.hfunderground.com/wiki/index.php?title=AM&diff=14527&oldid=prev R4002 at 10:46, 13 October 2022 2022-10-13T10:46:38Z

<p></p> <table style="background-color: white; color:black;"> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr valign='top'> <td colspan='2' style="background-color: white; color:black;">← Older revision</td> <td colspan='2' style="background-color: white; color:black;">Revision as of 10:46, 13 October 2022</td> </tr><tr><td colspan="2" class="diff-lineno">Line 1:</td> <td colspan="2" class="diff-lineno">Line 1:</td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Image:Amplitude Modulation.jpg|right|thumb|300px|Amplitude Modulation]]'''Amplitude modulation (AM)''' is one of the modes frequently used by pirates on [[HF]] and mediumwave. Often, pirates will use vintage [[amateur radio]] transmitters, such as those by E.F. Johnson (Valiant, Viking, Ranger), Globe and Heathkit. These transmitters are old, heavy and consume generous amounts of electricity, but are desirable because they can produce a relatively high fidelity, plate-modulated AM signal. At one time, these transmitters hardly had any value, but prices of vintage equipment have skyrocketed in the last decade. This may be one reason why AM is not quite as popular for pirate transmissions as it once was. Instead, many pirates prefer to use [[SSB]]. In addition, SSB is a more efficient mode. AM uses approximately 2/3 of its power on the carrier which contains no information but is needed to decode the signal. The remaining 1/3 of power is then used by two identical audio sidebands. SSB only transmits one audio sideband and the receiver generates the carrier, making it much more efficient. The downsides to SSB are that receivers are more complicated (and thus expensive) and most amateur transceivers limit the audio to have little bass and cut off high frequencies at 2.4 kHz. This audio filter is difficult to remove or disable and audio cannot be equalized to compensate for it. You must also be tuned to the exact frequency or the pitch will be wrong. AM transmitters are easy to make yourself and a homemade transmitter will have no audio cut off built in, allowing you to equalize the audio yourself before feeding it to the transmitter. Making an SSB transmitter yourself is nearly impossible.</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>[[Image:Amplitude Modulation.jpg|right|thumb|300px|Amplitude Modulation]]'''Amplitude modulation (AM)''' is one of the modes frequently used by pirates on [[HF]] and mediumwave. Often, pirates will use vintage [[amateur radio]] transmitters, such as those by E.F. Johnson (Valiant, Viking, Ranger), Globe and Heathkit. These transmitters are old, heavy and consume generous amounts of electricity, but are desirable because they can produce a relatively high fidelity, plate-modulated AM signal. At one time, these transmitters hardly had any value, but prices of vintage equipment have skyrocketed in the last decade. This may be one reason why AM is not quite as popular for pirate transmissions as it once was. Instead, many pirates prefer to use [[SSB]]. In addition, SSB is a more efficient mode. AM uses approximately 2/3 of its power on the carrier which contains no information but is needed to decode the signal. The remaining 1/3 of power is then used by two identical audio sidebands. SSB only transmits one audio sideband and the receiver generates the carrier, making it much more efficient. The downsides to SSB are that receivers are more complicated (and thus expensive) and most amateur transceivers limit the audio to have little bass and cut off high frequencies at 2.4 kHz. This audio filter is difficult to remove or disable and audio cannot be equalized to compensate for it. You must also be tuned to the exact frequency or the pitch will be wrong. AM transmitters are easy to make yourself and a homemade transmitter will have no audio cut off built in, allowing you to equalize the audio yourself before feeding it to the transmitter. Making an SSB transmitter yourself is nearly impossible.</div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div>AM is still extensively used on the medium wave broadcast band or the AM broadcast band, the shortwave [[Shortwave Broadcast Bands|broadcast bands]], for 11 meter [[CB radio]] (along with [[FM]] and SSB in many countries) as well as for [[VHF / UHF Radio|VHF]] (108-137 MHz) and [[VHF / UHF Radio|UHF]] (225-400 MHz) [[VHF_airband|aircraft band]] communications, [[https://www.hfunderground.com/wiki/index.php/VHF_airband#NAV_Navigation_VHF_VOR|aircraft]] navigation systems <del class="diffchange diffchange-inline">and </del>some legacy HF marine radio communications systems. <del class="diffchange diffchange-inline"> </del></div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>AM is still extensively used on the medium wave broadcast band or the AM broadcast band, the shortwave [[Shortwave Broadcast Bands|broadcast bands]], for 11 meter <ins class="diffchange diffchange-inline">27 MHz, </ins>[[<ins class="diffchange diffchange-inline">CB|</ins>CB radio]] (along with [[FM]] and SSB in many countries) as well as for [[VHF / UHF Radio|VHF]] (108-137 MHz) and [[VHF / UHF Radio|UHF]] (225-400 MHz) [[VHF_airband|aircraft band]] communications, [[https://www.hfunderground.com/wiki/index.php/VHF_airband#NAV_Navigation_VHF_VOR|aircraft]] navigation systems<ins class="diffchange diffchange-inline">, </ins>some legacy HF marine radio communications <ins class="diffchange diffchange-inline">systems and speciality marine radio </ins>systems.</div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>AM mode is also known by its [[Emission Designator|emission]] designation A3 or A3E.  </div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>AM mode is also known by its [[Emission Designator|emission]] designation A3 or A3E.  </div></td></tr> </table>

R4002