32V-2 no grid current - how to troubleshoot

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KJ4OLL:
My 32V-2 has worked for years on 75M.
Now there is no grid current.
Plate current 40 mills
Grid current zero
HV = 600 (I have the switch set to the lower value)
LV= 300
RF output = 0

I am not confident that I could troubleshoot/repair this myself, as I can find very little information about this unit other than what is in the manual.

A couple of guys told me that when their 32V-2 did this, a shorted screen bypass cap. on the 4D32 socket was the problem.

I looked in there, it appears to have been “designed” so as to make repair impossible. What a mess.

Anyway, it has been suggested that I start by measuring  the DC voltages around the final and driver.
Not sure of how to configure the test equipment.
I have a signal generator, and can inject a signal into the mic jack.
With the HV off and the LV on, should I be able to find a signal in these circuits?

Also, I found these test points next to the socket, but because of the way everything is jammed in there, can't tell what they connect to.


Plan "B" is to sell it to someone else that can fix it, or "C" scavenge the parts out of the chassis and sell them?

73
Frank
KJ4OLL

KA2DZT:
Most likely a failure of a component.  Put away your signal generator that's not going to help you.  Hopefully you have a VOM or some type of DVM.  There are plenty of folks on this forum that know that xmtr forwards and backwards.  I'm not one of them since I only have my own HB xmtrs. 

You should get some help soon.

If your set worked well for years it shouldn't be a big deal to get it working again.  May just be a tube that went south.

Fred

KJ4OLL:
I wish it was a tube, but I tested them all, except for the 4D32.
I don't have the socket adapter for this tube for the TV-10.
But I had spare 4D32's to swap in, no change in symptoms, so I do not suspect the 4D32.

So one or more components in these is the culprit:
 PTO not working
 Buffer not working
 Freq doubler not working

KA2DZT:
With all those circuits not working I would begin checking the low voltage B+ circuit.  Could be no B+ is reaching those circuits.  Not sure if that xmtr uses a clamp tube circuit on the final.  With no grid drive the clamp tube will drag down the final screen voltage limiting the final plate current to a safe level, something like you have, about 40 ma.

Fred

KC4VWU:
First thing to do is don't flip out. I'm sure sometime later, you'd kick yourself if you started stripping the thing to sell the parts. Can you hear any output in a nearby receiver?

I've got a basket case to revive here, a big project for when I don't have any other distractions. The tx is notorious for being a pain to work on because of its "modular" construction, kinda like 10 lbs. of s#!t in a 5 lb. bag. Just gather all your service info and scour the net for any service info, disassembly, and pics you can find; they'll be helpful. Also, don't dig in until you're 100% ready to do so.   

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