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#1
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It can be found under the section that allows a transmitter as long as it is
less than some number of milliwatts per meter. If you really need the exact section, I will drag out the regs and get it for you. "RST Engineering" wrote in message ... I can't find the part of the FCC regs that provide these frequencies for unlicensed stations. Can anybody share the chapter and verse? Jim There are a couple of frequiencies for unlicensed low power am stations. You can see them in use by real estate folks selling houses. There are no commercial stations on the frequency. Yes, and at Disney World, etc. This is a very doable idea and may well solve FCC/DoD issues. |
#2
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That is part 15 and it isn't just a couple of frequencies, it is any
frequency in the AM broadcast band (and the FM broadcast band, for that matter). Specifically, 15.219 allows operation on any frequency in the band so long as (a) the input power to the final stage is less than 100 mW and (b) the antenna "system" (radiating element, coax, and ground lead) is less than 3 meters long. 15.221 also allows operation with an unspecified power level into leaky coax with a field strength limitation. Power is not milliwatts per meter. Power is milliwatts. Field strength (also an allowed measurement) is in volts per meter. The OP said that there were a "couple of frequiencies(sic)for unlicensed low power am(sic) stations." That implied that there were a couple of frequencies that were unused in the AM band by commercial stations, and I just wanted to have a reference to WHAT they were and WHERE in the regs they were delineated. Jim "Fred W4JLE" wrote in message ... It can be found under the section that allows a transmitter as long as it is less than some number of milliwatts per meter. If you really need the exact section, I will drag out the regs and get it for you. "RST Engineering" wrote in message ... I can't find the part of the FCC regs that provide these frequencies for unlicensed stations. Can anybody share the chapter and verse? Jim There are a couple of frequiencies for unlicensed low power am stations. You can see them in use by real estate folks selling houses. There are no commercial stations on the frequency. Yes, and at Disney World, etc. This is a very doable idea and may well solve FCC/DoD issues. |
#3
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In this case the milliwatts per meter refers to frequencies stated in
meters. Volts per meter only applies to the E component, the magnetic component is always stated in amps per meter. I will get back to you on the specifics. I am pretty sure that my brain is not suffering from a senior moment as to my recollection of the regs. "RST Engineering" wrote in message ... Power is not milliwatts per meter. Power is milliwatts. Field strength (also an allowed measurement) is in volts per meter. |
#4
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On Tue, 4 Oct 2005 17:31:37 -0400, "Fred W4JLE"
wrote: In this case the milliwatts per meter refers to frequencies stated in meters. Hi Fred, Is this to suggest that for 300MHz it is 1mW total input power as say compared to 1MHz allowing 300mW? This would be uncharacteristically generous of the FCC whose regulations would ban emissions from dummy loads. Seems it would hardly serve Ari's search for pork, but I suppose grantsmanship would jump at sending a marathon of runners through the spill area - each carrying sub-Watt handi-talkies to provide the aggregate power, and spectrum, and lung volume necessary to "get the warning out." 73's Richard Clark, KB7QHC |
#5
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Richard the value changes per band and is stated in part 15. For example in
the broadcast band the formula is 24000 /F for microvolts at 1000 feet. There are certain bands that no emissions are allowed from a low powered device. For example setting up your neighborhood micro Rap Station on 121.5 MHz (aircraft emergency) would probably bring a swift shut down. I am still searching for the reg that allows fixed information stations. IIRC they can be run on 530 and 1750 KHz. I know in the past I had looked at the regs and the particular station I was researching was indeed legal. In the low freqs (140 KHz area) you can run up to 1 watt CW with out a license. "Richard Clark" wrote in message ... On Tue, 4 Oct 2005 17:31:37 -0400, "Fred W4JLE" wrote: In this case the milliwatts per meter refers to frequencies stated in meters. Hi Fred, Is this to suggest that for 300MHz it is 1mW total input power as say compared to 1MHz allowing 300mW? This would be uncharacteristically generous of the FCC whose regulations would ban emissions from dummy loads. Seems it would hardly serve Ari's search for pork, but I suppose grantsmanship would jump at sending a marathon of runners through the spill area - each carrying sub-Watt handi-talkies to provide the aggregate power, and spectrum, and lung volume necessary to "get the warning out." 73's Richard Clark, KB7QHC |
#6
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Not quite. That is the limit in 15.209, with the following caveat
"...except as provided elsewhere in this subpart..." Elsewhere in the subpart (15.219 and 15.221) we have the limit for the band 525-1705 kHz. (AM broadcast band) the 100 mW and 3 meter antenna restriction OR a 15 uV/m restriction at a distance of (47.715/(frequency in kHz.)) meters (which is also lambda/(2 * pi)) from leaky coax. BTW, it is 24000/F uV/m at 30 meters from 490 to 1705 kHz., which is more like 100 feet, not 1000 feet (15.209). Jim "Fred W4JLE" wrote in message ... Richard the value changes per band and is stated in part 15. For example in the broadcast band the formula is 24000 /F for microvolts at 1000 feet. |
#7
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On Tue, 4 Oct 2005 15:09:50 -0700, RST Engineering wrote:
Not quite. That is the limit in 15.209, with the following caveat "...except as provided elsewhere in this subpart..." Elsewhere in the subpart (15.219 and 15.221) we have the limit for the band 525-1705 kHz. (AM broadcast band) the 100 mW and 3 meter antenna restriction OR a 15 uV/m restriction at a distance of (47.715/(frequency in kHz.)) meters (which is also lambda/(2 * pi)) from leaky coax. BTW, it is 24000/F uV/m at 30 meters from 490 to 1705 kHz., which is more like 100 feet, not 1000 feet (15.209). Jim So if I need to go out 3500 feet or so, this won't work. Correct? -- Drop the alphabet for email |
#8
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You are correct Jim, mistyped the extra zero.
"RST Engineering" wrote in message ... Not quite. That is the limit in 15.209, with the following caveat "...except as provided elsewhere in this subpart..." Elsewhere in the subpart (15.219 and 15.221) we have the limit for the band 525-1705 kHz. (AM broadcast band) the 100 mW and 3 meter antenna restriction OR a 15 uV/m restriction at a distance of (47.715/(frequency in kHz.)) meters (which is also lambda/(2 * pi)) from leaky coax. BTW, it is 24000/F uV/m at 30 meters from 490 to 1705 kHz., which is more like 100 feet, not 1000 feet (15.209). Jim "Fred W4JLE" wrote in message ... Richard the value changes per band and is stated in part 15. For example in the broadcast band the formula is 24000 /F for microvolts at 1000 feet. |
#9
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On Tue, 04 Oct 2005 14:46:33 -0700, Richard Clark wrote:
Seems it would hardly serve Ari's search for pork, Hey, I'm Jewish, sort of. -- Drop the alphabet for email |
#10
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On Tue, 4 Oct 2005 13:51:06 -0700, RST Engineering wrote:
The OP said that there were a "couple of frequiencies(sic)for unlicensed low power am(sic) stations." That implied that there were a couple of frequencies that were unused in the AM band by commercial stations, and I just wanted to have a reference to WHAT they were and WHERE in the regs they were delineated. Jim Truth is, I was thinking about reserved but not yet assigned AM/FM frequencies. -- Drop the alphabet for email |
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