[Collins] Collins TCS12 mods

Fri, 13 Sep 2002 20:19:38 -0400

John,

You can build a preamp stage with an op-amp, into a small interface box and
power it up from the original carbon mike power source in the transmitter.
The only "unoriginal" component would be the microphone, which is a cheap
electret mike you can interface with the op-amp.
Or, you can still use the RS-38 original carbon mike with the op-amp
circuit.
There are circuits in abundance on the Internet with these circuits.

73, Meir WF2U,

Landrum, SC

 -----Original Message-----
From: 	[email protected] [mailto:[email protected]]
On Behalf Of John Nicholson
Sent:	Friday, September 13, 2002 7:39 PM
To:	[email protected]
Subject:	[Collins] Collins TCS12 mods

Hi Guys,
I use a Collins TCS12 in original condition on our AM nets, I get reports
from time to time that it lacks audio.
Not surprising since the mic transformer feeds direct to the grids of the
1625 modulators without any preamp.

Does anyone have or know where I can find any info on modifications I can
make to increase the modulation level? I want to keep the transmitter as
original as possible but have thought of removing one of the crystal
sockets and adding a pre-amp stage.

73
John Nicholson
ZL1AUB
SPAM Librarian,
(Society for Preservation of Amplitude Modulation)

Sponsored by the Collins Radio Association
http://www.collinsra.com