[MRCA] FW: BC-611 PS

[Mike Feher]

About 35 years ago I had some BC-611s ( I still have about 10). I wanted to
try them on the air but neither worked. They both had leaky coupling caps.
To save on current all stages are operated at real high impendences. Even a
very high resistance in a RC coupling network can turn the following grid
positive and cause distortion or at worse shut off the tube. The other
problem I found was open IF transformers. I fixed the problems and had good
working radios. I was also fortunate to have some good batteries. One
evening I decided to try them out. My 8 year old son at the time had one in
the kitchen and I started walking away from the house with the other. I was
able to go close to a mile and maintain comms in the dark on 3885 on a busy
band. For an RF gain control on receive I used my finger on the antenna
while holding the rig. The more pressure I applied the less the sensitivity,
Have fun. 73 - Mike 

 

Mike B. Feher, N4FS

89 Arnold Blvd.

Howell NJ 07731

848-245-9115

 

-----Original Message-----
From: mrca-bounces at mailman.qth.net <mailto:mrca-bounces at mailman.qth.net>
<mrca-bounces at mailman.qth.net <mailto:mrca-bounces at mailman.qth.net> > On
Behalf Of Gene Smar via MRCA
Sent: Friday, December 20, 2019 10:24 PM
To: 'Military Radio Collectors Association' <mrca at mailman.qth.net
<mailto:mrca at mailman.qth.net> >
Subject: Re: [MRCA] BC-611 PS

 

Gents:

 

     Today my BC-611F (?) arrived safe and sound and works (kind of).  To
provide an Executive Summary, the PTT seems to be sticking and the receive
crystal may not be right for the 3885 kcs transmit crystal.  Details and a
few follow-up questions for you follow below.

 

     After unpacking the -611 I noted that the PTT switch was permanently
depressed (not sad, just stuck) in "transmit."  I unscrewed the captive bolt
at the top of the case and attempted to remove the chassis but was not able
to.  I inspected the entire radio, then discovered that I had to disconnect
the red and black power leads from the bottom of the chassis.  (It's been a
while since the last time I worked on the guts of one of these machines.)
The chassis then slipped out easily.  When I got the chassis out pieces of
the plastic insulating strip that lays across the PTT contacts fell out from
the case.  I presumed I had found the reason that the PTT was stuck in
permanent transmit.  My first needed repair was noted.  

 

     With the entire chassis in my hand, I manipulated the PTT button on the
switch strip and the contacts made and broke as expected but they look
tarnished.  More on this switch later.  I reinserted the chassis into the
case and fastened the captive screw at the top.

 

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