(Quote jbprptco) Keith continues on his site with instructions to keep the ground wire away from all other metal, ie, use standoffs if the transmitter is on a metal mast or tower account, for, as he puts it, the ground wire needs to develop some impedence. This surely is another radiator, yet he's been certified by the FCC.
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Ironically, the impedance in the elevated "ground" conductor connection to true r-f ground actually would have better impedance bandwidth and less DC resistance if it was bonded to the metal mast or tower, instead of running down it on insulators -- which would reduce its loss to the r-f current it carries.
FCC records show that the Rangemaster has been Part 15 certified, but if that certification was done with the tx+3-m whip installed on an elevated mount with a long conducting path from its chassis to a true r-f ground at the surface of the earth, then operationally Part 15.219(b) was not being observed.
If it was certified with the tx+whip near ground level, and with a very short conductor to true r-f ground so that the length of the total did not exceed 3 meters, then installing it on an elevated mount with a long conductor to r-f ground is not covered by the certification on file.
Using a certified Part 15 AM tx doesn't mean that every installation of it automatically is Part 15 compliant. It still can be used in illegal ways.
Ok now so here it goes. So what you are telling me is that, If I have a Rangemaster, 100 milliwatt output with a 3 meter antenna and if I get a range of several miles, that's ok by the FCC? Someone posted filed measurements are not important as long as you stick to the 100 milliwatt power and 3 meter antenna. Whatever range you get with these requirements you will not get in trouble with the FEDS?
Hi,
Yes as long as you are in compliance with either 15.209 OR 15.219 (as allowed under 15.215) you are legal. Note that 15.219 limits the antenna, ground lead, and transmission line lengths to a TOTAL of 3 meters and power input to 100 mW. The FCC rules do not define a range limit for part 15 AM
If you can certify and demonstrate that your field strength meets the requirements of part 15.209, regardless of the limits of 15.219, then you can operate under that rule.
Please read rules 15.209, 15.215, and 15.219 and tell me your interpretation.
Neil
QUOTE
So what you are telling me is that, If I have a Rangemaster, 100 milliwatt output with a 3 meter antenna and if I get a range of several miles, that's ok by the FCC?
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If you do a web search for "Cadillac Radio" or "Transmitter sites from Hell" you will read about transmitter installations that folks tried, and failed, to get shut down because of that very issue. Cadillac had a program in the 1990s where they spent considerable money getting certified part 15 transmitters installed, then creating content that sounded like a local station and taffic report, telling motorists to pull into the caddy dealer because the traffic was bad. They even set up billboards advertising the "station." Many had ranges of a mile or more, and passed repeated FCC inspections.
OPINION - OPINION - OPINION
In my opinion, and I've mentioned this several times, and it's only my opinion, content is a factor, too. I think the regs give the FCC enough flexibility to shut down a station they want to shut down, and to ignore a station they want to ignore. I imagine that means there will be a jurisdictional variance, as well. I feel that if you're experimenting with low power broadcasting and transmitting things like NOAA weather reports or looping car commercials, I think you will likely be held to a different standard than a person who broadcasts material that makes a licensee or community members feel threatened or uncomfortable. I feel that a licensee complaint is pretty much a death knell, no matter what you're doing, because licensees pay spectrum fees and I feel the FCC is going to protect their interests at all costs.
Love reading everyone's discussions on this, but as I also like to say, put the fire to the wire and see for yourself 🙂
by MRAM 1500 kHz
Not to ruffle feathers but on the matter of the FCC giving special considerations, consider BPL.
BPL IS A PART 15 OPERATION. As we all know, that little sticker we put on our transmitters clearly states that if it causes interference to licensed services it must be shut down.
When BPL became the buzz word, the equipment used to implement BPL wreaked havoc on the HF frequencies, i.e. ham radio. BPL is a broadband internet access that travels on AC power lines. The frequencies used had the potential to cause a great deal of interference to many LICENSED services.
The ARRL, a national organization of ham operators, had to go to great extreems to convince the FCC to shut down an interferring BPL system. The BPL operators simply ignored complaints or worse, acknowledged the complaint and did nothing. The FCC seemed to "sit" on complaints forever until legal action was pursued by the ARRL. Fortunately, newer BPL systems seem to co-exist with ham frequencies but BPL was initially given a great deal of lattitude for a non-licensed, Part 15 service.
Yes, the FCC certainly does have the flexibility to shut down any of us. But don't lose site of the fact that they have given us the right to exist. To paraphrase what SCWIS has said, you will be judged by the content you broadcast and the toes you step on.
The last guy you want to see...
YES... Check out the talking Billboards in Los Angeles...They are all over town. They use a certified part 15 transmitter, mounted on top of 80' billboards.