On 10/25/2022 4:47 PM Burt K6OQK <biwa@...> wrote:

John,

I personally do not believe in the 5 kHz in and 5 kHz out thinking.? A part of the problem is that stations with low deviation will come through with low deviation and those with high deviation can hit the transmitter's limiter too hard.? Some believe that it's the responsibility of those stations to correct their deviation, and learn to use correct mic technique. My experience in that area has proven to be: Good Luck!

Please understand, I don't mean to be talking at you, but just intellectualizing with you...

To my way of thinking, a repeater is not a piece of test equipment to be used as a deviation tester.? It's a contraption to improve / enable communications.? Proper processing also protects the transmitter and adjacent channel spectrum in a less destructive way.? Anything I can do to make it simple, reliable, and pleasant, is a plus.? That's why I have always used appropriate audio processing on my repeaters.? I've gotten arguments from the unwashed telling me that it brings up the noise on the incoming signal. Well, yes, that's true, but you're going to have to turn up the volume at the user's end if you want to hear those stations anyway.? When you do that you are not only bringing up the noise heard by the repeater, but also any noise between and the repeater.? Having to turn the volume up and down while listening to a repeater gets tiring after a while.

For what it's worth,

Burt, K6OQK

jb,

I want to assure you that WA6TDD was not that way when I ran it.? Once it started to turn in that direction I tried my best to clean it up.? When that failed I got rid of it.? I will not be a part of that kind of operation.? Please do not associate me with the .435 operation.

Burt, K6OQK

On Tue, Oct 25, 2022 at 01:32 PM, jb wrote:

Then I looked up K6OQK and saw 147.435 in Los Angeles.? I think that one is world famous for sending the FCC packing, and pushing the envelope well past the 7 dirty words.? Maybe when Burt was involved it wasn't that way, but it became the attractive nuisance of the amateur community.? stories like that prevented me from even toying with the idea of putting up a ham repeater.? I have dabbled with remotes, but keep it real low key.? I have enough trouble with commercial 2way to keep me busy.


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Then I looked up K6OQK and saw 147.435 in Los Angeles.? I think that one is world famous for sending the FCC packing, and pushing the envelope well past the 7 dirty words.? Maybe when Burt was involved it wasn't that way, but it became the attractive nuisance of the amateur community.? stories like that prevented me from even toying with the idea of putting up a ham repeater.? I have dabbled with remotes, but keep it real low key.? I have enough trouble with commercial 2way to keep me busy.

At 10/24/2022 06:59 PM, you wrote:

When I first saw the question, I scratched my head and went on to other things. It looked wierd. Then I remembered why.
If you are actually going to feed audio up to 6 khz. to the modulator, where does it actually go after that???
Even if you reduce the deviation and the pre-emphasis to keep the bandwidth down to a normal FM channel, anyone trying
to recieve it will have to modify the reciever so it won't squelch itself out trying to recieve.

Literally hundreds of 440 repeaters in this area have audio responses approaching 6 kHz, & no one has had to modify their RXs to hear them.

Sounds confusing, but the typical 16kF3 reciever needs to have a 20khz bandwidth in the IF to allow for drift and to prevent
the reciever from squelching out. The back-end was made to roll off above 3khz to the speech amp and the squelch amp will
be listening for noise above that to keep the squelch closed.

Much above, actually. The last squelch circuit I looked at actually responded best to noise around 10-20 kHz, so 6 kHz won't really affect it much

If this is for a link radio on the 2m ham band, how were you planning to keep the bandwidth to a normal ham channel? If this is
for a ham voice repeater, everyone will have to modify their radios to use it.

Nope - see above. Granted on 2 meters with 15 kHz channel spacing some modifications to the standard are needed. I find that by keeping the deviation down to, say 4.2 kHz peak, the occupied BW is sufficiently controlled without losing S/N. Also the audio has to have a flat response (aside from the usual 6 dB/octave pre-emphasis). Any extra slope that favors the high frequencies or hard clipping will shift the PSD to the high end, greatly increasing the occupied bandwidth.

Bob NO6B

On 10/25/2022 12:47 PM Bob Dengler via groups.io <no6b@...> wrote:


At 10/25/2022 05:35 AM, you wrote:

I've done flat audio in the pass but always use a RC filter to roll off above 3-4khz...no need to go higher as the energy in that area is QUITE low and not needed..I've made GE MVPs rptrs with flat audio and FM on the exciter where it coupled to an ACC RC850 passed Alinco Digital with no problem...had to back off the radio deviation a little...it would clip thru the rptr at high deviation..

I've ran Quantars in flat audio mode using the RSS settings and found great results..but I would never use 5kHz audio b/w...the Carson rule of B/W tells me not to anyway ..it exceeds 16-20K easily.

The above two paragraphs contradict each other: if the spectral energy above 3 kHz is "QUITE low", then that spectrum will not be deviating the TX anywhere near 5 kHz, hence the BW will not be "16-20K". This is probably why I can tune my TYT TH-9800 15 kHz away from the W6MEP 147.240 repeater & listen to a repeater on 147.225 some 50+ miles away with no interference. In the end that is all that matters.

Bob NO6B