[ICOM] TNC and Mike Distortion in IC728 and IC735

[Mike McCarthy, W1NR]

Did you try audio isolation transformers in the TNC audio lines?  Sounds
like a ground loop problem.  You might have to use an opto isolator in the
PTT line as well to keep all of the TNC grounds isolated from the rigs.

Mike, W1NR
 

-----Original Message-----
From: icom-bounces at mailman.qth.net [mailto:icom-bounces at mailman.qth.net] On
Behalf Of J. Coote
Sent: Friday, May 13, 2005 10:54 PM
To: icom-all at yahoogroups.com; icom at mailman.qth.net
Subject: [ICOM] TNC and Mike Distortion in IC728 and IC735

I've run several KAMs in different IC735s and in one IC728.
One source of irritation is the TNCs usually have to be unplugged from the
accessories connector when using voice, otherwise there will be distortion
and "crud" in the transmitted audio.

I need a way to keep the TNCs plugged in- so our EOC radios can be used in
voice or data instantly and won't start looking like science projects.

I'd appreciate any fixes.

Thanks,
Jay
W6CJ/AAR9QM

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