A main argument to support enforcement actions is that unlicensed radio broadcasts interfere with aviation and public safety.
Does anyone know of any structured, published tests?
If there are none, I’m interested in structuring a test to evaluate this claim. Some questions to answer would include:
At what point can an FM broadcast be heard on an AM aviation radio? (Trials of different frequencies, power, antennas, receiver types, distances)
I have resources to call on in both domains, in California. We could enlist media or social media talent, or publish a report publicly. I would propose a team of interested parties. We would develop a proposed test plan, and understand options for locales and legality of the test.
Let me know if you’re aware of past tests like this, or are interested in doing our own: glenn@west.net
Wouldn't it be easier to ask the FAA? They will have records of all complaints. So will the FCC. We have a Freedom of Info request system here in UK and I think you have something similar in the US?
I have read some reports of pilots listening to heavy Drum n Bass music on final approach to London Heathrow airport. And in one case pilots unable to hear ATC transmissions due to interference from houshold lightbulbs. Yes those glowing filament vintage style bulbs caused a major problem at one airport here!
Good luck with your quest. I'd be interested to know what you're aiming to achieve or is this an academic study.
Wouldn't it be easier to ask the FAA? They will have records of all complaints. So will the FCC. We have a Freedom of Info request system here in UK and I think you have something similar in the US?
I have read some reports of pilots listening to heavy Drum n Bass music on final approach to London Heathrow airport. And in one case pilots unable to hear ATC transmissions due to interference from houshold lightbulbs. Yes those glowing filament vintage style bulbs caused a major problem at one airport here!
Good luck with your quest. I'd be interested to know what you're aiming to achieve or is this an academic study.
Thanks for the reply, info and ideas. Yes we have FoIA but I’m not so much interested in acknowledging FAA or FCC complaint data, as testing some real life scenarios to see where the line is for FM broadcast band Tx interference on AM aviation band equipment and other FM commercial / public safety equipment. For example we could use or build an RF anachoid chamber, or explore real life Tx with some typical mobile FM VHF/UHF and airborne AM aircraft (ours). Perhaps in a remote area or Indian reservation. I think London’s FM pirate scene is probably the most dense on the planet, even today. But my hypothesis is that in the US, the FCC dogma about interference is exaggerated. There have been a lot of community unlicensed stations shut down which I doubt caused much, if any, interference. So I’m interested in testing this claim. If the results show that interference is common across bands, deviation, modulation types, then the policy may be justified. But if the test were to show little or no interference, it could potentially be used in legal defenses of prosecuted parties in the US. But the test would need to be formally documented and published.
Very interesting and a noble cause indeed. Thanks for taking the time to explain.
One variable that's very hard to deal with is xmitter quality.
Judging by what I read on the various boards, there must be 10s of 1000s of chinese rigs operating in the US. Most seem to operate between 5 and 15 watts. And more recently I've been reading about people hooking these rigs up to the new 150w chinese amps.
At 15w I suspect one of these rigs has the potential to come through on almost any frequency within a 1/4 mile. At 150w it could be 1/2 mile or more.
In areas of low RF activity of any sort it's hardly an issue but if you have planes circling overhead or on final approach at 3000 ft, maybe even higher, I'd say there's a good chance of interference.
So in summary, I'm 100% with you if we're talking about broadcast quality xmitters. They don't interfere. But I don't think most people are using broadcast quality xmitters and the situation is getting worse, not better.
Incidentally, the London pirates generally pride themselves on build quality. Even so, there have been some disaster builds over the years pushing out 150+w and interfering with everything you could imagine. Rightly, they were raided and confiscated by the authorities pretty quickly. Conversely, well built rigs seem to stay on and are more likely to be stolen than raided.
