Again, controlling deviation has nothing to do with the audio components of the signal. The audio does not change based on the deviation. (short of audible distortion if it exceeds the passband)
I agree it is your responsibility to make sure that your TX does not overdeviate, but there is absolutely nothing you can do to change the overdeviation of the user's radio. (short of telling him to fix it) Let's keep the discussion of the audio limited to the audio and not add more issues to an already complex problem. All this said, there is nothing in Part 97 that limits your deviation. This is likely why so many radios are overdeviated from the factory - a problem which I acknowledge, but do not see a relationship to audio. Many radios have crappy audio, too. I've been evaluating a new commercial unit for a manufacturer that sounds worse than any ham radio I've ever heard. Yes, it's understandable, but the audio is tinny and sounds like crap compared to other current commercial radios. Yet, the deviation is fine. ;-> Joe M. N9WYS wrote: > > Gentlemen, > > I've been sitting in the wings following this thread, and I think it's time > I added my 2¢ worth... > > First of all, I'm not in the business, but I am in the hobby. If I read > Part 97 correctly, the FCC requires that >>I<<, as the control > operator/trustee of a repeater, ensure that **my** repeater emissions are in > compliance with said Rules (97.307, inclusive). In doing so, the FCC has > mandated that I "fix the problems" caused by users who transmit with > too-wide a deviation. Yes, the individual repeater user is responsible for > THEIR emissions on the input frequency, but it is my opinion that I am > responsible for the ones that come out of my repeater. If someone transmits > in with too much deviation, and I retransmit such product back out on my > repeater, then **I** am at fault. (In addition to the user on the input.) > > To prevent this, I set max deviation on my 440 repeater at about 4.5 kHz > including any CTCSS mixed in with the voice, and the deviation on my 900 > machine at about 2.2, IIRC. (In actuality, the deviation on my 900 machine > is a bit low - it requires more "volume control twist" on the user's end > than it probably should... but that's another discussion.) This keeps me > within the bandwidth of the frequency allocation, and the FCC off my back > for causing adjacent-channel interference. (Forgive me if I'm not using the > proper technical phraseology/wording - I'm merely trying to get my point > across.) Nor does this "...intentionally make properly set-up radios sound > worse." At least the output wont be over-deviating. > > What I think Skipp was trying to say (and forgive me, Skipp, if I'm putting > words in your mouth) is that a LOT of radios coming from the Pacific Rim are > coming in with the deviation set right at, if not a bit higher than "spec." > I see this when I switch between commercial gear which I have converted for > Amateur use, and the stuff I own that is "Amateur out of the box." (And all > of them are as guilty as the next - Icom, Yaesu, Kenwood, et al.) I get > told to "back off the mic" because my audio is "too hot", or that I'm > "sounding a little fuzzy". (Of course, that is until I adjust it down... I > dont personally have the necessary technical equipment to be able to adjust > radios 24/7, so when I detect a problem, I borrow the necessary item (be it > a Service Monitor, or other). > > On the other hand, I have to agree with Joe when he says that some hams are > overly obsessed with the quality of the audio emanating from a given > repeater... to a fault in some cases, as far as I'm concerned. I have one > user on my machine that complains **every time** ANYONE is less than full > quieting into the machine, or when the machine is less than full quieting on > his radio. Forget the fact that he can successfully complete his > communication - he isn't happy with the audio. I think that if I provided > him with repeater output audio direct-wired through Sennheiser > studio-quality headphones that he'd still complain. Let him try HF SSB just > once... > > For now... > > 73 de Mark - N9WYS > (Also GROL) > > -----Original Message----- > From: [email protected] On Behalf Of mch > > skipp025 wrote: > > > > > Actually, 'flat response' is better. Since the de-emph/pre-emph > > > changes the audio intentionally, the term 'processed audio' is > > > more applicable to such a repeater. > > > > I and probably most of the two-way radio industry do not agree. It's > > really about what part of the hardware you are actually talking about. > > Well, most of the two-way industry doesn't really care about repeater > audio the way hams do. If you can understand what the other person is > saying, it's good enough. There is even one commercial repeater near me > that has open squelch on the tail. Yea - that sounds good. > > > > If it sounds dull and weak, that is because the USER RADIOS made > > > it that way. A properly set up repeater will not alter the audio > > > at all. > > > > So... are you going to hold a clinic for user radios to crank down > > (properly set) the voice, ctcss deviation and audio levels? We > > did at local club meetings for many years and could never seem to > > keep up with all the new radios. So we set our repeaters up to > > clean up most of the average radios. Everyone sounds like a breath > > of spring... well most everyone. A few guys still need to brush > > their teeth more often. > > You completely missed the point. It's not up to the repeater to fix user > problems. Yes, it would be nice if all hams could properly maintain > their equipment. It would be nice if they could install a 3-wire CTCSS > encoder that has +, ground, and audio out. It would even be nice if all > hams knew how to actually operate their equipment. > ---> But enough with fantasy-land <--- > > In the real world, if someone's radio sounds crappy, it needs fixed by > someone or the radio will get a (well deserved) reputation as a POS and > people need to know to not buy that model. Yes, we had clinics, too. > But, many hams feel that if they are understandable, that is 'good > enough'. Of course, people who compensate for their shortcomings in the > repeater only serve to accommodate the problem rather than solve it. > > > What we like as our properly set up repeater does alter the average > > users audio so we can better keep our sanity in check. But that's > > what we like and use based on our experience. > > Then you are not in favor of a flat audio repeater (whatever term you > want to call it), and intentionally make properly set up radios sound > worse. This of course adds to the reason to not set up a user radio > properly. "Let someone else solve my problem" seems to be the rationale > in your area, I guess. I would prefer the real source of the problem to > be fixed rather than eliminating the symptom. Granted, it's not the > 'easy way out', but it's the right thing to do. > > > > Fix the problem at the source - don't try to make the repeater > > > correct for problems in the user radios. > > > > Typical voice and ctcss over deviation? Not going to happen in > > most cases. Just just learn to expect and deal with it... Most > > Amateur Radios are cranked up as sent-out or sold from the Dealers. > > Then maybe the passband of the receiver should be tightened up more. > When those people are choppy on all the repeaters, they might consider > getting their radio properly serviced. > > What will you do when the problem gets worse and even more out of > tolerance radios come out? And they will come out since perhaps 10% > overdeviation seems to be working fine, so why worry about keeping it > within 15%? Then 20%? Etc. Pretty soon, you will have everyone on "radio > welfare". Transmitting AM rather than FM? No problem - we will just fix > it in the repeater. I know that's getting ridiculous, but when you allow > some slop, you have to expect more slop to follow. The real solution is > to not compensate for the existing slop. Tell the users to "get a job" > (learn their craft and fix their radios, or take it somewhere to get > them fixed). > > > Never had anyone say our repeater audio sounds bad Joe. Everyone > > likes (so far) what we do. Everyone goes in different and everyone > > comes out standard deviation clean, clear and loud. No squelch crash > > and real ctcss with revese burst. It's very sexy... > > CTCSS is stripped and regenerated on nearly all repeaters - even those > using unprocessed audio. Otherwise, you would have falsing of decoders > on all the co-channel user radios if you were to simply pass everything > down to DC (or even 60 Hz). Been there - tried it early on in my > 'repeater career' way before CTCSS was common in the ham bands. Repeater > sounded excellent. Audio response was down to almost DC. Sounded just > like the input audio. CTCSS decoders went nuts with the audio components > below 250 Hz. That's another problem with some of the user radios - no > high pass filters to keep from bringing up other repeaters due to the > low frequency components on their TX. > > Squelch crash? What does that have to do with audio processing? That is > a function of an audio delay circuit (a proper one which will not change > the audio at all, but simply mutes it); Apples and lemons. > > Joe M. > > > Yahoo! Groups Links > > >
