Re: {Collins} 32S-3 grid meter pins backwards immediately upon turning on the unit



What version neutralization capacitor does your transmitter use?

Reverse grid current is sometimes indicative of a shorted (smoked!) variable
ceramic trimmer in the PA neutralization network.
(I've never seen this happen with the newer type "bread-slicer" style cap
however.)

Also be aware, you should never simply remove the 5R4 to kill the HI B+
without removing the "PA Disable" jumper between the two phono jacks on the
rear panel.
Leaving the jumper in place, screen voltage is applied without plate
voltage, where-by the screen acts as a plate and will draw destroying
current.

It is perfectly safe to have plate voltage WITHOUT screen voltage, but NOT
the other way around.  (Sorry if this is old news to you.)

73, Charlie k3ICH




-----Original Message-----
From: Collins <collins-bounces+pincon=erols.com@xxxxxxxxxxxxx> On Behalf Of
Gary Schauffler via Collins
Sent: Wednesday, August 21, 2019 5:39 PM
To: collins@xxxxxxxxxxxxx
Subject: {Collins} 32S-3 grid meter pins backwards immediately upon turning
on the unit

I have a 32S-3 that I recently acquired that has several problems.?? The
first of which is that immediately after turning it on (the FREQ. 
CONTROL is switched to Trans VFO) the meter, if it's in the grid position,
pins backwards.?? The MIC GAIN is at minimum and the position of the MODE
switch has no affect on the backward pin.?? This happens whether or not the
5R4 and 5U4 rectifiers are in the power supply. ?? In the ALC position the
meter reads 0, and in the PLATE position it reads about 40 ma if the
rectifiers are in the power supply or 0 if they aren't which seems normal
indicating the meter isn't the problem.?? 
Studying the schematic I can't see where there would be a source that would
provide current through the grid meter resistor (R54) opposite of the normal
grid current direction thereby causing the meter to pin backwards.?? At
first I thought it may be a leaky bypass capacitor, like
C84 or C62.?? I temporarily disconnected C84 from ground but the grid meter
still pinned backwards, so that isn't the problem.?? From Fig. 6-7 in the
manual it looks like C62 is under the aluminum shield covering the rear
wafer of the band switch.?? I removed this shield but for the life of me I
can't find C62, a 1000 pf ceramic disc capacitor, there or anywhere nearby
as far as I can tell. Was C62 not in the circuit for some units and in it
for others? Before powering up the 32S-3 I checked all the tubes and found 6
questionable ones that I replaced, and I made the resistance and voltage
checks per the instruction manual (Table 4-2) and the readings look to be
reasonable for the most part.?? Any thoughts on what to check would be
greatly appreciated because I'm stuck! 
Thanks.?? 73, Gary W8KM

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