开云体育

Hi Chris,

Thanks for your comments and observations.

On my repeater... no, I don't run the audio out to 5 kHz, but at the same time I don't have the sharp 2.5 or 3 kHz cutoff that many systems have.? I've learned over the years that if you're running through various pieces of equipment that have the same roll off or cutoff, you'll have ringing.? All of my system, and it is a stand alone repeater, and not tied to other systems, is wideband audio.? The audio is only "band-stopped" just prior to going into the modulator, But at the same time, I don't want that to be a sharp cutoff.? I do regularly monitor my occupied bandwidth, and only once have I had a complaint from a neighbor which I immediately took care of by lowering the deviation a tad.? That was caused by a previous mis-adjustment on my part.

As far as running "flat audio," not sure what that means as there have been so many opinions on that term.? In the case of my system, I de-emphasize the audio out of the receiver so that I'm only dealing with "flat audio" from all my sources and then pre-emphasizing the audio just ahead of the modulator.? Keep in mind, the modulator is direct FM.

Regarding two-way radio, pre and de-emphasis is always a compromise, as there really is no common standard and each manufacturer seems to have their own standard.? Even in the case of phase modulation, which has it's own natural pre-emphasis - the breaking point, if you will, is different between various equipment manufacturers.? It may not be very scientific, but I use a pot to adjust de-emphasis and adjust to what sounds pleasant.? It's a compromise.

Anyway, it is "Ham Radio" and thankfully we are not tied to the two-way business "standards".? We can strive to make things sound pleasant and at the same time use good engineering practices.? I do not bow to the Motorola gods and I don't speak Motorolaese.? :)

I'm sure we'll have more discussion on this, which is a good and pleasant thing.

Burt, K6OQK