[Hallicrafters] HT-32B

[Bill Gerhold]

You will also need to change the dropping resistor for the bias supply since
the voltage will be too high (after changing the selenium rectifier) for the
bias adjustment pot to compensate.  In my HT-37, I had to just about double
the value of the dropping resistor so I could get the bias voltage to -49vdc
with the bias pot.

Without the increased value of the dropping resistor I could only get the
bias voltage down to about -75vdc using the bias pot.  Try to select a value
that will allow you to adjust the bias voltage just below the recommended
-49vdc.  Remember, the -49vdc bias voltage is set while the rig is in
transmit.

K2WH

-----Original Message-----
From: hallicrafters-bounces at mailman.qth.net
[mailto:hallicrafters-bounces at mailman.qth.net] On Behalf Of Langston, Mike
Sent: Saturday, March 05, 2005 4:14 PM
To: Hallicrafters at mailman.qth.net
Subject: [Hallicrafters] HT-32B

I'm refurbishing a nice HT-32B. It has the original power transformer
and it checks good. I want to keep it that way. I have searched the
archives and I know this topic has been discussed before but I'm still
uncertain what causes the transformer failures. 

 

1.	I am replacing both rectifier tubes with plug-in solid state
units and will use dropping resistors to obtain correct output voltages.
It seems like I remember some talk about disconnecting the 5V windings
from the tube sockets because they tend to short to the HV windings. Any
knowledge about this?
2.	I am replacing the bias supply selenium rectifier with an
appropriate value diode.
3.	I have replaced all electrolytic and paper capacitors.

 

Any comments, advice or other suggestions regarding modification of the
power supply would be appreciated.

 

 Thanks and 73,

Mike Langston KL7CD

Dallas-Ft. Worth

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