Bob, et. Al:
> >Signal reports heard being given today are largely "ego reports" and are >of little to no value. When was the last time you heard a report >indicating ones audio is distorted, or sounds like the transmitter has a >bit of FM, or there's buck shot heard 10 kHz away, or there's a noise, >humm or a buzz on your signal? Nope, we don't want to offend anyone >and thus seemingly just roll out a meaningless, non constructive >report. I suppose to many of us have forgotten what we learned; "if you >can't say something nice, then don't say anything at all". > Well, you obviously have not worked me :) Audio transmission quality is a subject close to my heart. While I understand all the technical issues regarding Intermodulation Distortion in 12v vs 48 volt and Tube vs Solid State amps, the proof is in the pudding: Just listen on the air! You will find folks running Class A rigs that sound horrible due to overprocessing and the belief that turning all the transmit audio knobs all the way to ELEVEN and seeing dancing meters make for great signals. Processor missadjustment is a worse culprit than IMD and, although IMD products do harm, processor knobs turned all the way to the right are the main culprit in the mess that has become our SSB subbands. There are some operators I can't understand at all. Worse, some of the "Audio VooDoo" ESSB types have so much bass that they create a phantom carrier, making their signal copyable in AM mode. On many of these, I even able to lock my WinRadio SDR to the pseudo carrier in Synchronous AM mode! In the last CQ WW SSB, I started to think that my signal was too clean and too bandwidth efficient versus my "competitors". That lovely, raspy, sharp, dense MP1000 sound (not to blame a particular radio, but I know how to make that one sound that way), while certainly "penetrating", is difficult to listen to, and, when overdone, makes it hard to understand. That means lost QSO's. Want to increase your score? Consider making better audio! Overdone processing by and large creates listener fatigue and intelligibility problems. A 10 second contest QSO, while not creating fatigue on its own, when joined by 300 of them, will. Wonder why you are tired after a short stint on 40m in WorldWide Friday night? This might be the answer! Transmitter IMD in this scenario is still there, however, exacerbating the problem. And some contesters will use their IMD "wideness" as a weapon of advantage in the competition. There is nothing we can do in our receivers to counteract this. We are at their mercy. Where is the Wouff Hong and the Rettysnich? We need you now more than ever! If we are going to campaign against anything, I would say campaign against over-processing. Once we get them to understand that issue, then we can concentrate on IMD. With some of the signals I hear on the air today, IMD is the least of our worry in a world where everybody is Fine Nine oh Five. Audio quality is a very personal thing, like your car choice, radio choice or your hair coloring chemical choices... I wish everyone had the common sense to make articulate, clear, yet punchy and "communications quality" audio by avoiding the temptation to eke out that last watt. When we all do that, then we can worry about Amplifier IMD. Processing issues heard on the air today simply make the discussion of final amplifier spectral purity moot. Respectfully Lu - W4LT K-Line ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
