Hi Maury,
The HT-32 is a great xmtr, I use mine weekly. But there are a few
"gotchas" in it.
First off, don't power it up yet (or again). The HT-32 & HT-37 (plus
other Halli xfmrs) are prone to picking up moisture if in storage for
any length of time. The HV winding will short to one of the 5v windings
fairly soon after powering up in it's been stored. If any question, put
a 60 watt light bulb under it for a day or 3 to warm it up and drive out
moisture.
The problem then can be avoided by installing SS diodes in place of
both rectifiers, and disconnecting the 5v leads from both sockets.
Second, the bias supply has a selenium rectifier in it that probably
has gone bad and you won't get enough negative bias voltage on the
finals to cut them off when you let the key or mike switch up. If it's
not too bad, the AC fuse, if it's proper size, will blow after a while.
If a prev. owner has installed a bigger fuse, and the bias voltage is
too far off, the finals will melt down.
You can see some of my experiences with the HT-32/37's at
<http://boatanchors.org/HT37.htm> The SS diodes are covered abt half
way down the pg. I don't think I've put anything out on the bias
rectifier fix, but a small SS diode will do the job, but since it has
much less voltage drop it will need a dropping resistor added at its
output. IIRC, 2k-3k will be reqd.
The fan will probably be noisy, if not now, after a while. Replace it
with a small fan from a PC or elsewhere, with a proper pwr supply to it.
(blowing out).
The AC line is isolated from the chassis, no problem with that. When
you install a 3-wire cord, wire the hot (black wire to the fuse, and the
neutral (white) to the other line, xfmr primary. The green wire to any
convenient ground point.
I hope this is of some help to you,
73,
Al, W8UT
www.boatanchors.org
www.hammarlund.info
"There is nothing -- absolutely nothing -- half so much
worth doing as simply messing about in boats"
Ratty, to Mole
On 8/7/2019 10:08 AM, Maury Guzick wrote:
I appreciate all the replies.
I have been replacing worn out 2 wire power cords with newer 2 wire cords of
similar style on radios with one side grounded to the chassis.
I am at the moment looking at bringing back to life a HT-32 I got for $10. But
the AC is or has been lifted off the chassis. There have been a number of mods
under the chassis. So I want to have a better understanding of how to rewire
the power cord.
I also am looking at some antique radios that are AC/DC types that will need
new cords, so this inquiry is multipurpose.
73MauryW5IO
On Tuesday, August 6, 2019, 7:17:20 PM CDT, Eric <[email protected]> wrote:
My very unlearned opinion.....
Connecting a supposed to be floating metal cabinet to the grounding wire
and then using the hot and neutral wires to connect to the chassis
inside the cabinet would protect against the cabinet from "going hot".
As far as I know this is the entire purpose of the grounding wire.
If the cabinet is wood, plastic or some other insulating material,then I
can't see any reason to install a 3 wire cord & plug.
Eric
WB6TIX
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