>From: Kevin Custer <[EMAIL PROTECTED]> > > > >My suggestion for properly de-emphasizing repeater audio is to use this >circuit: >http://www.n1uec.org/n1uec/deemphasis.html >
I suggest that a small value resistor (220 ohm or so) be added to the output to prevent any capacitive loading of the op amp. Some op amps will oscillate with as little as 100 pF across their output. This small amount of capacitance is easily built up over just a few feet of shielded audio cable. If the op amp breaks into oscillation, it will probably be ultrasonic so you wouldn't be able to tell without a scope that anything was wrong. But if the circuit directly feeds into a modulator, the resulting spurious emissions would be "significant", to say the least. Bob NO6B 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: http://docs.yahoo.com/info/terms/
