Chip, thanks for the insightful comments. You're spot on that the ARRL staff should not try to go it alone in trying to "protect" our interests but should also elicit assistance from the amateur radio community (in all nations) who are professionally involved in technology developments that could impact future spectrum uses in these ways. In regards to HF IMD from ISM devices, would these QRM waveforms be loosely analogous to the old OTHR Woodpecker? And the FCC proposal would to be to ignore the disastrous effects on some modes and simply suggest ham receivers, as done for the 'Pecker, have active filters, noise-blankers, specifically designed to mitigate them. Although probably far more effective in SDR architectures, wouldn't this still create unacceptable distortion to "legacy" analog voice modes, ie, SSB, AM, and depending on the still arbitrary threshold levels, potentially even drop-outs to DV? Or far lowered bit-rates / SNR thresholds in digital data modes? All of which would be a bitter pill to swallow for licensed hams, and seem to be contrary to many fundamental objectives of our service mission. I am also troubled that this PN docket implies the FCC is seeking to get out of or vastly subcontract, AT RECEIVING USERS EXPENSE, the burdens of gathering evidence for enforcement in either an excessive noise floor or future waveform out-of-limits cases. Especially onerous if foreign-made non-compliant devices are further allowed to flood into our marketplace. 73 de John WØPV
The FCC does nothing for Amateur Radio, I have not seen any enforcement done to people maliciously causing interference on HF bands, all of you have experienced such activity and even with complaints filed the FCC only responds by email saying it is being looked into, but nothing gets done. Lets face it commercial radio, television, cable, cell phone, and such own the FCC, not us. Our hobby is in a downward spiral and it started when code was dropped, wont be long they will drop the need of having to pass a Test for you to get a Tech License. They do not care about our opinion and ARRL has not got much power any longer. Addressing the FCC proposal, in a nut shell were in the middle of a land grab , since the politicians do not make much money from us they are going in favor of the ones that will line there pockets.
Is "armature Radio" a reference to the Alexanderson alternator? https://en.wikipedia.org/wiki/Alexanderson_alternator
Right now most rigs use fairly simple DSP noise reduction algorithms, general pretty effective. However, the waveforms of much of this future IMD --will-- be fairly easy to pick out and thus remove with a fourier transform/matched filter in somewhat more sophisticated NR. The woodpecker was highly periodic and that made it easy to remove with analog filtering. Not so with these freakin OFDM (or other) IMD products.... Basically, if next generation filtering is used, it SIMPLIFIES the ham's problem with interference, because anything that gets past the filtering is much too strong for the FCC to ignore, IMO. IOW it will be easier to make the case and push it through. If China, for example, continues to send crap with interference, this will be an excuse to ban those imports in favor of clean(er) American products. The present administration is highly sympathetic with that, IMO. Yep. Sleuthing RFI will be a new cottage industry--that hams can make a livelihood. Unless we keep playing publicity hero and giving it away...
You are part of the problem with that attitude. Typical BS Well, we just have to go along. Turn in your ticket and watch soap operas.
Nice try to take the spotlight off of their bylaw changes. The Newington Piggies will stop at nothing to cover for their ba$t@rdry.
AMEN to that. To the government, ours is a service, not a hobby. Perhaps this distinction is part of what's missing in the arrl's brain stem. The arrl has too much cash, lacks decent leadership, and has no solid mission. Plus, it has no clue as to the challenges facing the most important component of our Service, emergency and public service communication.
Ha! If most of these clubs are anything like the local clubs around my area, the 'A' in their names stand for 'apathetic not 'amateur'. Forming a new organization won't do jack...
You may see it as sidestepping. The simple fact is the ARRL Leadership in the last few years seems to have stagnated. Their latest 'FIX' has gone a long way to alienating the amateur population. It is not just a few rogue hams disparaging the league.
This is quite an amazing response. May I kindly suggest that you read my comments again , as you evince no evidence of understanding. On the contrary: what I said was if you invoke-- modern noise reduction at the RX-- and still have interference, it totally removes the gray area of whether the interference should be pursued. Yes, it should be pursued in that case. R-I-G-H-T ? To wit, and I quote: ---------------------------------------------------- "Basically, if next generation filtering is used, it SIMPLIFIES the ham's problem with interference, because anything that gets past the filtering is much too strong for the FCC to ignore, IMO. IOW it will be easier to make the case and push it through. If China, for example, continues to send crap with interference, this will be an excuse to ban those imports in favor of clean(er) American products. The present administration is highly sympathetic with that, IMO." --------------------------------------------------------------------------- If I am part of the problem then I jump up in down in high spirits and smiling personage in supporting the 'problem' as 'solution. Now your nod head slowly and say 'I'm sorry'....
Chip, We share a fatalistic POV regarding competition for and future sharing of spectrum, but with all due respect, could there be a slight bias in your reply supportive of commercial interests and away from amateur radio? Perhaps I just need more enlightenment on the possibilities of next-gen filter technology. It's great if in the FCC's proposed future scenario, where Part 97 allocations are more shared, if the non-ham IMD QRM is getting past an "FCC approved" next-gen ham receiver filtering system, it could then immediately be classified as "out of limits" and therefore subject to rapid enforcement measures. But, are you claiming that such an advanced (FFT) ham receiver filter method would completely reject overlapping non-ham IMD QRM within significant limits WITHOUT also causing objectionable side effects on "legacy" analog voice modes? (SSB, AM) Even with a next generation DSP-SDR as you suggest, its hard for me to imagine there would NOT still be substantial signal degradation, lowered SNR, and/or distortion to the resulting desired analog signal audio reproduced after such filtering. For analog modes (SSB, etc) at best that would probably be a significant and ruinous change to the current amateur experience and at worst make them largely unusable and obsolete. The QRM is gone but the weak DX attenuated or SSB/AM ragchew QSO ain't anywhere near "hi-fi" anymore. I am concerned that under such a proposed FCC plan, shifting legal QRM burden from producer prevention to user mitigation, the main modes left usable by hams would only be those most tolerant and compatible with dependence on such advanced receiver filtering, ie, digitized vocoders and FSK data modems. An amateur radio experience which I imagine to be kinda suckish ... 73, John WØPV
Well, no I am not informally or formally writing up any such moves to the FCC nor my customers. It's quite the opposite: I tell them that there are real circumstances where the 50 dB down IMD with all those devices at ISM will produces interference locally at HF, and that could be a problem for BOTH FCC licensees and NTIA USERS. I certainly didn't come up with the idea of better noise reduction at RX as a possible mandate. However, I do see its merits in keeping that interference tolerable, up to some level, because the NR at RX can REMOVE IT nearly to the NOISE FLOOR. If you have all that stuff IMD'ing in apartment buildings in cities, you will indeed see this problem. AND if you have really crappy incidental radiators, it will be intolerable. The major problem will be keeping the crappy incidental radiators out of the US markets. So, where is the 'anti-ham' message here? The problem, and solution is not limited to hams, and I benefit in no way whether the restrictions are placed on the receivers or not. I can tell you right now that if you keep the physical antenna aperture down in size, the HF IMD goes down also, so in that perspective what I do REDUCES the IMD interference. No one is saying you should adopt NR for RX to deal with grow lamps. They just need to be pulled from the market, as should all other crappy incidental radiators.
