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#31
August 10th 06, 04:45 PM
posted to rec.radio.amateur.antenna,rec.radio.amateur.policy,rec.radio.shortwave
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STATION IS ON 13.556.00 MHz. LSB
John - KD5YI wrote: You are wrong about the FCC limits on 13 MHz. There is no mention of 10,000 uV/m. Here are the limits: Sec. 15.225 Operation within the band 13.110-14.010 MHz. (a) The field strength of any emissions within the band 13.553- 13.567 MHz shall not exceed 15,848 microvolts/meter at 30 meters. (b) Within the bands 13.410-13.553 MHz and 13.567-13.710 MHz, the field strength of any emissions shall not exceed 334 microvolts/meter at 30 meters. (c) Within the bands 13.110-13.410 MHz and 13.710-14.010 MHz the field strength of any emissions shall not exceed 106 microvolts/meter at 30 meters. You are also wrong about the power level required to achieve these limits. The power required is much lower. Cheers, John There appear to be two sets of part 15.225 rules floating around. http://frwebgate.access.gpo.gov/cgi-bin/get-cfr.cgi?TITLE=47&PART=15&SECTION=225&YEAR=2001&TYP E=TEXT shows: "[Code of Federal Regulations] [Title 47, Volume 1] [Revised as of October 1, 2001] From the U.S. Government Printing Office via GPO Access [CITE: 47CFR15.225] [Page 726] TITLE 47--TELECOMMUNICATION CHAPTER I--FEDERAL COMMUNICATIONS COMMISSION PART 15--RADIO FREQUENCY DEVICES--Table of Contents Subpart C--Intentional Radiators Sec. 15.225 Operation within the band 13.553-13.567 MHz. (a) The field strength of any emissions within this band shall not exceed 10,000 microvolts/meter at 30 meters. (b) The field strength of any emissions appearing outside of this band shall not exceed the general radiated emission limits shown in Sec. 15.209. (c) The frequency tolerance of the carrier signal shall be maintained within plus-minus0.01% of the operating frequency over a temperature variation of -20 degrees to +50 degrees C at normal supply voltage, and for a variation in the primary supply voltage from 85% to 115% of the rated supply voltage at a temperature of 20 degrees C. For battery operated equipment, the equipment tests shall be performed using a new battery." And http://www.fcc.gov/Bureaus/Engineering_Technology/Documents/bulletins/oet63/oet63rev.pdf Also shows the 10,000uV/M at 30M Yet http://www.sss-mag.com/pdf/part15-91905.pdf Dated sept 2005, shows the limits you quoted. What is troubling is the FCC has different specs on different documents at fcc.gov. Buy regardless of runinng 10,000uV or 15,848uV, one does NOT need a 100W transmitter to reach either of these levels. I have a 2W unit followed by a step attenuator coupled to a bufffer with a Zin of 50 Ohms and a Z Out of ~500. The buffer transistor is a 250mW and isn't even warm. This was the only easy way to allow the attenuator to accurately step the power level down. By the 15,848uV I guess I could increase my power from 5,000uV, to allow for the energy in the sidebands, to something like 10,000uV. Oh whoopy gea! Too much trouble to even think about changing as I had to back the exciter down to something like 1/2W to reach the 5,000uV level. Crystal Oscillator-buffer#1-amplifier-?20dB pad-step attenuator-buffer#2-matching- very poor radiator. I would guess I am running maybe 5mW into a modified CB ground plane antenna. Serious mismatch, but my "beacon" was only intended to reach about 1 mile. For an S2 reading I had to back the power down ~50% from max legal. So assume I am running 2.5mW with no attenuation, so for extra credit, what is my power level at -63dB? Terry |
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#32
August 10th 06, 04:50 PM
posted to rec.radio.shortwave
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STATION IS ON 13.556.00 MHz. LSB
Dale Parfitt wrote: "Slow Code" wrote in message nk.net... "Dale Parfitt" wrote in news:R0aCg.15333$l95.9940@trnddc08: So if N9OGL's transmitions are legal power wise, he would basically be broadcasting for the kids across the street. Maybe he could take song requests. They can just shout out their front doors what songs they want him to play. SC I can copy perhaps 8 beacons on 13.555 MHz from all across the U.S. Assuming they too are running the power level Roy calculated, N9OGL's beacon should also be copyable. Dale W4OP You don't need to tell me the strengths of CW. I'm a CW advocate. Just listen to the NCDXF beacons on 14.100. You can easily hear the 100mW tone all over the world when there is propagation with a simple antenna. I'm just saying the RF Todd is puting into his antenna has to be quit low if he is transmitting legal power wise. Sc I too enjoy CW- probably 90% of my operating. My comment was that if his ERP is the same as the other beacons, then he will be heard well beyond "across the street". The beacon 'HI' is my regular here. Operating on 13558v in CW from Connecticut. Audible at 1545. dxAce Michigan USA |
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#33
August 10th 06, 05:47 PM
posted to rec.radio.shortwave
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STATION IS ON 13.556.00 MHz. LSB
That Bell South womans washing machine next door works real good.I slip
over there and I wash my filthy nasty clothes and she and that other woman doesn't know anything about it,yet. cuhulin |
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#34
August 10th 06, 06:45 PM
posted to rec.radio.amateur.antenna,rec.radio.amateur.policy,rec.radio.shortwave
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STATION IS ON 13.556.00 MHz. LSB
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#35
August 11th 06, 01:19 AM
posted to rec.radio.amateur.antenna,rec.radio.amateur.policy,rec.radio.shortwave
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STATION IS ON 13.556.00 MHz. LSB
"Dale Parfitt" wrote in
news:CKFCg.56002$gU4.47279@trnddc07: "Slow Code" wrote in message nk.net... "Dale Parfitt" wrote in news:R0aCg.15333$l95.9940@trnddc08: So if N9OGL's transmitions are legal power wise, he would basically be broadcasting for the kids across the street. Maybe he could take song requests. They can just shout out their front doors what songs they want him to play. SC I can copy perhaps 8 beacons on 13.555 MHz from all across the U.S. Assuming they too are running the power level Roy calculated, N9OGL's beacon should also be copyable. Dale W4OP You don't need to tell me the strengths of CW. I'm a CW advocate. Just listen to the NCDXF beacons on 14.100. You can easily hear the 100mW tone all over the world when there is propagation with a simple antenna. I'm just saying the RF Todd is puting into his antenna has to be quit low if he is transmitting legal power wise. Sc I too enjoy CW- probably 90% of my operating. My comment was that if his ERP is the same as the other beacons, then he will be heard well beyond "across the street". W4OP I'll try to copy a few of those beacons. Maybe there is info on about the stations, and possible they have a waiver for an increase in power or antenna size. Sc |
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#36
August 11th 06, 01:33 AM
posted to rec.radio.amateur.antenna,rec.radio.amateur.policy,rec.radio.shortwave
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STATION IS ON 13.556.00 MHz. LSB
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#37
August 11th 06, 04:29 AM
posted to rec.radio.amateur.antenna,rec.radio.amateur.policy,rec.radio.shortwave
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STATION IS ON 13.556.00 MHz. LSB
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#39
August 11th 06, 09:46 PM
posted to rec.radio.amateur.antenna,rec.radio.amateur.policy,rec.radio.shortwave
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STATION IS ON 13.556.00 MHz. LSB
In article om,
wrote: John - KD5YI wrote: wrote: I would guess I am running maybe 5mW into a modified CB ground plane antenna. Serious mismatch, but my "beacon" was only intended to reach about 1 mile. For an S2 reading I had to back the power down ~50% from max legal. So assume I am running 2.5mW with no attenuation, so for extra credit, what is my power level at -63dB? Terry Your question makes no sense. What is the reference level? 1 watt, 1 mW, 5 mW, 2.5 mW? .5 microwatts is 63 dB below a Watt. .5 nanowatts is 63 dB below a milliwatt. 2.5 nanowatts is 63 dB below 5 milliwatts. 1.25 nanowatts is 63 dB below 2.5 milliwatts. (Is this the one you want?) 2.5 milliwatts is 3 dB below 5 milliwatts. See a pattern in any of this? Once again I see why I should not take up comedy. It wasn't a serious question. I was reffereing to 5mW at 50 Ohms. Fewer people would get confused by posts if dBm instead of dB were used when transmit power level or receiver sensitivity is spoken. I know I would. dB being a relative measure should only be used when speaking of a component like an attenuator or amplifier not a level of power and just invites the possibility of confusing the reader. -- Telamon Ventura, California |
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