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Scope of the term "Amateur"
On Tue, 28 Jun 2016 23:41:21 -0400, rickman wrote:
The term "amateur" is often applied to people who have obtained a license to use radio equipment for communications. Is this term inclusive of those who don't obtain a license but use receivers for various uses? I believe the term was used to describe anyone that indulges in RF but does NOT charge for their efforts. The FCC wanted to distinguish between commerical (for profit) services, and amateur (not for profit) services. For reception only, the term was "SWL" or short wave listener. I guess that also applies to only listening on just about any frequency from ELF to satellite communications. https://en.wikipedia.org/wiki/Shortwave_listening No license required to just listen. I have been looking into design of receivers in the LF to ELF frequency ranges. Is this part of "amateur" radio? Mostly yet. However, some bands do not require a license and operate under FCC Part 15: http://www.lwca.org https://en.wikipedia.org/wiki/LowFER http://www.arrl.org/lf-low-frequency https://hackaday.io/project/6882-lowfer-transmitter-for-your-arduino etc... -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
#2
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Scope of the term "Amateur"
On 6/29/2016 10:59 AM, Jeff Liebermann wrote:
On Tue, 28 Jun 2016 23:41:21 -0400, rickman wrote: The term "amateur" is often applied to people who have obtained a license to use radio equipment for communications. Is this term inclusive of those who don't obtain a license but use receivers for various uses? I believe the term was used to describe anyone that indulges in RF but does NOT charge for their efforts. The FCC wanted to distinguish between commerical (for profit) services, and amateur (not for profit) services. For reception only, the term was "SWL" or short wave listener. I guess that also applies to only listening on just about any frequency from ELF to satellite communications. https://en.wikipedia.org/wiki/Shortwave_listening No license required to just listen. I have been looking into design of receivers in the LF to ELF frequency ranges. Is this part of "amateur" radio? Mostly yet. However, some bands do not require a license and operate under FCC Part 15: http://www.lwca.org https://en.wikipedia.org/wiki/LowFER http://www.arrl.org/lf-low-frequency https://hackaday.io/project/6882-lowfer-transmitter-for-your-arduino etc... Very interesting. I see a difference between the ARRL article and the Hackaday page. ARRL says the power limit on the US 1750 meter "free band" is 1 W into the "transmitter's final stage" while the Hackaday page says the limit is 1 W into the "feedline" and antenna system. -- Rick C |
#3
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Scope of the term "Amateur"
On Wed, 29 Jun 2016 11:29:12 -0400, rickman wrote:
Mostly yet. That should be "yes". In a hurry today (like all other days). However, some bands do not require a license and operate under FCC Part 15: http://www.lwca.org https://en.wikipedia.org/wiki/LowFER http://www.arrl.org/lf-low-frequency https://hackaday.io/project/6882-lowfer-transmitter-for-your-arduino etc... Very interesting. I see a difference between the ARRL article and the Hackaday page. ARRL says the power limit on the US 1750 meter "free band" is 1 W into the "transmitter's final stage" while the Hackaday page says the limit is 1 W into the "feedline" and antenna system. This might help: http://www.lwca.org/sitepage/part15/index-what.htm http://lwca.org/library/reference/ Note that it's a bit out of date. Adjust the links for 2016. You want part 15.217 (Operation in the band 160-190 kHz.) http://www.ka7oei.com/ct_lowfer_archive.html I see that kind of stuff quite a bit in the FCC rules-n-regs. They sometimes fail to specify WHERE the transmit power is to be measured. Is it at the input to the xmitter, output of the xmitter or at the end of a lossy feed line. What does one do if the system is not 50 ohms? I don't have an answer and since the FCC never will admit to making a mistake, it's unlikely to be fixed. Should you ask for clarification, you'll probably get an answer from the FCC which you don't want to hear. Been there, many times. My best advice is do your best with what you have, don't try to play FCC attorney, and muddle onward into the unknown. Gone... -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
#4
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Scope of the term "Amateur"
On 6/29/2016 12:19 PM, Jeff Liebermann wrote:
On Wed, 29 Jun 2016 11:29:12 -0400, rickman wrote: Mostly yet. That should be "yes". In a hurry today (like all other days). However, some bands do not require a license and operate under FCC Part 15: http://www.lwca.org https://en.wikipedia.org/wiki/LowFER http://www.arrl.org/lf-low-frequency https://hackaday.io/project/6882-lowfer-transmitter-for-your-arduino etc... Very interesting. I see a difference between the ARRL article and the Hackaday page. ARRL says the power limit on the US 1750 meter "free band" is 1 W into the "transmitter's final stage" while the Hackaday page says the limit is 1 W into the "feedline" and antenna system. This might help: http://www.lwca.org/sitepage/part15/index-what.htm http://lwca.org/library/reference/ Note that it's a bit out of date. Adjust the links for 2016. You want part 15.217 (Operation in the band 160-190 kHz.) http://www.ka7oei.com/ct_lowfer_archive.html I see that kind of stuff quite a bit in the FCC rules-n-regs. They sometimes fail to specify WHERE the transmit power is to be measured. Is it at the input to the xmitter, output of the xmitter or at the end of a lossy feed line. What does one do if the system is not 50 ohms? I don't have an answer and since the FCC never will admit to making a mistake, it's unlikely to be fixed. Should you ask for clarification, you'll probably get an answer from the FCC which you don't want to hear. Been there, many times. My best advice is do your best with what you have, don't try to play FCC attorney, and muddle onward into the unknown. Thanks for the links. I found 15.217 and it says, 15.217 Operation in the band 160–190 kHz. (a) The total input power to the final radio frequency stage (exclusive of fila- ment or heater power) shall not exceed one watt. Since they specifically exclude the filament power I supposed that 1 watt limit is on the power from the supply rather than the "input" power to the grid/base/gate of the active element. So in reality the 1 watt limit at the input to the final stage will produce less than 1 watt at the output of the final stage. With the frequency being so low, a class D output could potentially provide nearly the full watt to the feedline I expect. Some amount of filtering would be needed to prevent the carrier from making it out the antenna, but using sigma-delta techniques should help to minimize that. With such low power and simple output stage, it could be placed at the antenna which would allow the full 15 meters to be antenna. -- Rick C |
#5
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Scope of the term "Amateur"
On Wed, 29 Jun 2016 12:53:28 -0400, rickman wrote:
I'm back from the dentist drilling holes in my teeth and bank account. Thanks for the links. I found 15.217 and it says, 15.217 Operation in the band 160–190 kHz. (a) The total input power to the final radio frequency stage (exclusive of fila- ment or heater power) shall not exceed one watt. Yep, that's it. Since they specifically exclude the filament power I supposed that 1 watt limit is on the power from the supply rather than the "input" power to the grid/base/gate of the active element. So in reality the 1 watt limit at the input to the final stage will produce less than 1 watt at the output of the final stage. With the frequency being so low, a class D output could potentially provide nearly the full watt to the feedline I expect. Some amount of filtering would be needed to prevent the carrier from making it out the antenna, but using sigma-delta techniques should help to minimize that. Yep, except why bother with an amplifier? You could just modulate a 200Khz switching power supply and get similar results. Lots of other options available, but few of them involve a traditional amplifier multiplier chain. With such low power and simple output stage, it could be placed at the antenna which would allow the full 15 meters to be antenna. Any way you look at it, it's going to be flea power buried under tons of atmospheric noise. Everything you do up to about 300 meters range is near field. http://www.part15.us/forum/part15-forums/general-discussion/part-15-am-communications-near-field http://www.part15.us/forum/part15-forums/general-discussion/longwave-broadcast-dx-171-khz -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
#6
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Scope of the term "Amateur"
On Wed, 29 Jun 2016 07:59:51 -0700, Jeff Liebermann
wrote: I have been looking into design of receivers in the LF to ELF frequency ranges. Is this part of "amateur" radio? Mostly yet. However, some bands do not require a license and operate under FCC Part 15: I forgot to mumble something about which bands require an amateur license and which do not under Part 15. The lowest frequency band that requires a ham license is 160 meters (1.8 to 2.0 MHz). http://www.arrl.org/frequency-allocations The various bands below that fall under Part 15.xxx as intentional radiator rules and do NOT require a license. However, 135.7 to 137.8Khz (2200 meters) is designated as an amateur radio band by the ITU. However, since it more easily falls under unlicensed Part 15 rules, the FCC does not require an amateur license to operate there. These bands are not world wide and vary by national jurisdiction: https://en.wikipedia.org/wiki/LowFER https://en.wikipedia.org/wiki/2200-meter_band Most LOWFER experimenters have ham radio call signs and use them on the LOWFER frequencies. There is no requirement to identify with an amateur call sign, but it is convenient. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
#7
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Scope of the term "Amateur"
On Thu, 30 Jun 2016, Jeff wrote:
I forgot to mumble something about which bands require an amateur license and which do not under Part 15. The lowest frequency band that requires a ham license is 160 meters (1.8 to 2.0 MHz). http://www.arrl.org/frequency-allocations That of course depends on which country you live in. In the UK 137kHz is an band that requires an amateur licence, with a power limit of 1W ERP (a significant difference to 1W into the PA stage)!! 427 to 479kHz is also an amateur band in the UK with a 5W erp limit I think the US is a tad behind, but that may have already changed. Here in Canada we definitely have one of the new LF bands, but I can't remember the details. As long ago as WARC 79 there was talk of making that low frequency license free band a ham band, so finally that's come to fruition, more or less. Michael |
#8
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Scope of the term "Amateur"
Michael Black wrote:
On Thu, 30 Jun 2016, Jeff wrote: I forgot to mumble something about which bands require an amateur license and which do not under Part 15. The lowest frequency band that requires a ham license is 160 meters (1.8 to 2.0 MHz). http://www.arrl.org/frequency-allocations That of course depends on which country you live in. In the UK 137kHz is an band that requires an amateur licence, with a power limit of 1W ERP (a significant difference to 1W into the PA stage)!! 427 to 479kHz is also an amateur band in the UK with a 5W erp limit I think the US is a tad behind, but that may have already changed. Here in Canada we definitely have one of the new LF bands, but I can't remember the details. As long ago as WARC 79 there was talk of making that low frequency license free band a ham band, so finally that's come to fruition, more or less. Here in the Netherlands amateur radio licenses have been scrapped some ten years ago. We have no licenses anymore. The amateur bands are now all "license free bands with obligatory registration", like maritime VHF radio. You just apply for a callsign and away you go, without license. To apply for a callsign you still need to pass an exam, just like with maritime VHF. So to the outsider the system may look the same. And in fact, many amateurs still talk about "the license". But there isn't any. |
#9
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Scope of the term "Amateur"
Rob wrote:
Michael Black wrote: On Thu, 30 Jun 2016, Jeff wrote: I forgot to mumble something about which bands require an amateur license and which do not under Part 15. The lowest frequency band that requires a ham license is 160 meters (1.8 to 2.0 MHz). http://www.arrl.org/frequency-allocations That of course depends on which country you live in. In the UK 137kHz is an band that requires an amateur licence, with a power limit of 1W ERP (a significant difference to 1W into the PA stage)!! 427 to 479kHz is also an amateur band in the UK with a 5W erp limit I think the US is a tad behind, but that may have already changed. Here in Canada we definitely have one of the new LF bands, but I can't remember the details. As long ago as WARC 79 there was talk of making that low frequency license free band a ham band, so finally that's come to fruition, more or less. Here in the Netherlands amateur radio licenses have been scrapped some ten years ago. We have no licenses anymore. The amateur bands are now all "license free bands with obligatory registration", like maritime VHF radio. You just apply for a callsign and away you go, without license. To apply for a callsign you still need to pass an exam, just like with maritime VHF. So to the outsider the system may look the same. And in fact, many amateurs still talk about "the license". But there isn't any. Does that mean anyone in the Netherllands can transmit on amateur frequencies provided they don't a callsign that sounds like an amateur one? -- Roger Hayter |
#10
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Scope of the term "Amateur"
Roger Hayter wrote:
Rob wrote: Michael Black wrote: On Thu, 30 Jun 2016, Jeff wrote: I forgot to mumble something about which bands require an amateur license and which do not under Part 15. The lowest frequency band that requires a ham license is 160 meters (1.8 to 2.0 MHz). http://www.arrl.org/frequency-allocations That of course depends on which country you live in. In the UK 137kHz is an band that requires an amateur licence, with a power limit of 1W ERP (a significant difference to 1W into the PA stage)!! 427 to 479kHz is also an amateur band in the UK with a 5W erp limit I think the US is a tad behind, but that may have already changed. Here in Canada we definitely have one of the new LF bands, but I can't remember the details. As long ago as WARC 79 there was talk of making that low frequency license free band a ham band, so finally that's come to fruition, more or less. Here in the Netherlands amateur radio licenses have been scrapped some ten years ago. We have no licenses anymore. The amateur bands are now all "license free bands with obligatory registration", like maritime VHF radio. You just apply for a callsign and away you go, without license. To apply for a callsign you still need to pass an exam, just like with maritime VHF. So to the outsider the system may look the same. And in fact, many amateurs still talk about "the license". But there isn't any. Does that mean anyone in the Netherllands can transmit on amateur frequencies provided they don't a callsign that sounds like an amateur one? In practice yes, but I think that is true in any country. However, to legally transmit on the amateur bands you need to register a callsign at the authorities. You can register any callsign within the range PA1-PH9 that has not yet been registered by someone else. To be able to do such a registration, you must first prove your technical knowledge by passing an exam at an accredited organization. Before this change, the authorities organized the exams and those that passed were issued a license, with associated callsign. The change was motivated as "deregulation" and "cost saving" (the license had a yearly fee and the registration was free), but in the meantime a yearly fee for registration has been introduced, albeit much lower than the previous fee for a license. Some hams believe that without a license they have less protection against interference and intruders. They believed that the license not only allowed them to transmit on the bands but also got them some protection against others doing so (including unintentional transmissions like interference from digital equipment). Interference is becoming worse and worse, and involvement from authorities is becoming less, but there is no real indication that it is related to that change. |
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