Wow! Not exactly the news I wanted, Mike, but thanks for the honesty.
It looks like I may have to move the speech amp and mic considerably
further away from the "E" model. I have an "H" and "I" model, but they
are still in the refurb process. Potted modulation transformers or any
modulation transformer for the 610 series is scarce. I have a UTC that
will work, but it's not potted and I have an oil filled military
transformer that would work if I had room on the chassis. I wonder what
the guys in the SCR-399 did to contend with this issue since they were
in such close quarters? Anyway, back to the drawing board and thanks
again for the info.
73,
Rick/K5IZ
Mike Sawyer wrote:
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" <[email protected]>
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:[email protected]
AMfone Website: http://www.amfone.net
AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb
______________________________________________________________
AMRadio mailing list
Home: http://mailman.qth.net/mailman/listinfo/amradio
Help: http://mailman.qth.net/mmfaq.html
Post: mailto:[email protected]
AMfone Website: http://www.amfone.net
AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb
