Re: [Repeater-Builder] Audio Reproduction

[scomind]

Hi Eric,   Hello Bob, so tell me what kind of buffering Op Apm are you using in you controllers? I've used the LM324 quad opamps but I can still tell I my audio sound different comming out of my HT than the repeater. I am taking my audio directly off the discrimanator going through a opamp with de-emphasis then to the mic input. I still don't like the way it sounds. I'm using a motorola mitrek mobile for a repeater. Are that PM or True FM?   We've been using the MC34074 for many years because it doesn't oscillate when driving a varying capacitive load. That's kind of a special requirement because we use op amps to feed a crosspoint switch that distributes the audio to various destinations, and the crosspoint looks like a fairly big capacitive load that varies with the number of switches that are turned on.   While you may need a special op amp for certain applications, most op amps work fine for this kind of thing and I don't think the LM324 is the source of your problem. It could be the corner frequency of the de-emphasis circuit, an impedance mismatch, a level problem, etc.   Maybe you could post a sketch of the circuit?   I don't have a Mitrek book here, so someone else will have to comment on the modulation method. BTW, I'm curious - - what's the difference between True FM and FM?   73, Bob WA9FBO Yahoo! Groups Links To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/   To unsubscribe from this group, send an email to: [EMAIL PROTECTED]   Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.