Rick, Unfortunately, you are plagued with the same problem dozens of -610 owners have. The only way to resolve it is to get an I or H model modulation transformer. They are potted and hermetically sealed and don't talk back near as much. Other than that you are SOL. Mod-U-Lator, Mike(y) W3SLK ----- Original Message ----- From: "Rick Brashear" <[EMAIL PROTECTED]> To: "Discussion of AM Radio" <amradio@mailman.qth.net> Sent: Thursday, March 16, 2006 10:42 PM Subject: [AMRadio] Modulator feedback
I've posed a couple of questions on some other lists and received some good advice, but I am still in need of more. My BC-610-E has a bad feedback or "talk back" problem. I've placed a capacitor across the overload relay (RY-5) and that did eliminate a little of the talk back. However, with much audio gain at all, not nearly enough to attain 100% modulation, I get feedback. Not just talk back, but feedback. I have to assume it's coming from the modulation transformer. The modulator bias is set for 40 ma as specifications state. The bolts on the modulation transformer are all tight. What am I over looking here? I'm using a BC-614-E speech amplifier with a D-104 non amplified mic. I did a few modifications to the dynamic input circuitry of the BC-614 to better match the D-104, but that is the only modification in either the speech amp or the BC-610-E. Rick/K5IZ ______________________________________________________________ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb