{Collins} Re: New 32V-3 Owner, LV Rectifier, XFMR, Question



Hi Scott,

The 5Z4 rectifier is definitely the culprit in at least some of the LV
transformer failures.  It's an indirectly heated cathode rectifier and very
prone to shorting.  My 32V-3 still has the original transformer.  When I
acquired the transmitter, it had a 5V4 subbed for the 5Z4; still an
indirectly heated cathode rectifier but less prone to shorting than the 5Z4.

Recently, I solid-stated the LV supply to play it safe.  I used dropping
resistors to keeping the voltage down.  The transformer gets only warm to
the touch even after several hours.  

Good luck getting it out of the trunk.  And be careful removing it from the
case-- the last time I removed mine I broke the OD3 voltage regulator :-)

I hope to hear you on the air with it soon.

73,

Clark, K9OA 


-----Original Message-----
From: collins-bounce@xxxxxxxxxxxxxxxxxxxxx
[mailto:collins-bounce@xxxxxxxxxxxxxxxxxxxxx] On Behalf Of Freeberg, Scott
(STP)
Sent: Thursday, May 29, 2008 9:45 AM
To: collins@xxxxxxxxxxxxx
Subject: {Collins} New 32V-3 Owner, LV Rectifier, XFMR, Question

GM, I just acquired a nice 32V-3 transmitter with a blown LV transformer.
It's still in the trunk as I work up the strength and back muscles to haul
it into the shack :>  I've already checked in with Gary Brown about getting
the transformer rewound so I have that base covered.  

Before I put a new xfmr in, I need to find out why it blew in the first
place. The fellow I got the V-3 from said he's heard talk over the years
that the 5Z4 LV rectifier tube has been known to short out.  Has anyone here
heard that?  

Has the LV transformer been known to be weak in it's old age or are there
any known trouble areas in the LV circuitry?  That LV transformer supplies
all filament voltages including the HV rectifiers so I know it's possible
that it lost HV isolation among other things.

Before I pull the transfomer and ship it off, I'm going to pretend that
there is a slight chance the transformer is still good, just smoking.... due
to a short on the LV B+ somehwere..  or do I have  better chance of getting
struck by lightning or winning the lottery?    

Thanks for any comments or advice.  

Gee the 32V-3 manual sure is pretty with the color front cover.  I'll be
pairing up the 32V-3 with my 75A-4 and running CW and AM with it.

73, Scott WA9WFA

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 NETS: Tues & Thur: 3.805 MHz-2000 Central + Fri: 3.895 MHz-2000 Pacific
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