Re: {Collins} Tough problem in still 32S-3 (still)



You might try hitting the feed thru cap with freeze spray and see if it gets better. I've never seen the failure mode myself but it's my understanding that if a feedthru is leaking to ground it can get worse as the cap is warmer.Jim N4KHSent from my Verizon, Samsung Galaxy smartphone
-------- Original message --------From: Steve via Collins <collins@xxxxxxxxxxxxx> Date: 8/4/19  09:19  (GMT-06:00) To: "Collins Reflector(CCA)" <collins@xxxxxxxxxxxxx>, Grayson Evans <wa4gvm@xxxxxxxxx> Subject: Re: {Collins} Tough problem in still 32S-3 (still) Hi Grayson,    Your explanation is really excellent.  I'll be very curious to find out exactly what the solution to the problem ends up to be.  I have a round 32S-3 here that works fine.  If there's anything measurement I can make to help you out, please let me know.    Best of luck to you!    Steve  K2FW----- Original Message -----From: Grayson Evans via Collins <collins@xxxxxxxxxxxxx>Reply-To: Grayson Evans <wa4gvm@xxxxxxxxx>To: <collins@xxxxxxxxxxxxx> <collins@xxxxxxxxxxxxx>Sent: 8/4/2019 9:42:02 AMSubject: {Collins} Tough problem in still 32S-3 (still)I have posted before about the tough problem Im having with a round 32S-3 that I restored.Everything works except there is no or very little ALC voltage being generated while transmitting.I have two 32S transmitters.By comparing the voltages and resistances between a working winged 32S-3 and my not working round 32S-3 I have been able to narrow down where the problem is caused, but I can’t find anything that is causing it exactly.  No bad tube or component.I am really stumped.   Ready to put it back on the shelf and hope the next owner can fix it!Hoping MAYBE someone here has a clue.The ALC circuit is a bit complicated.  the output signal of the 6CL6 driver is sampled at one end of C62 (a threaded feedthru cap) through R34 and eventually feed to CR5 and 6 that rectify the waveform to extract a DC voltage proportional to the output speech waveform, and apply the negative DC to the IF amp and RF amp. grids.This works fine in my winged 32S.In the round 32S I am getting very little signal from the end of C62 and thus no ALC.  The problem is the circuitry around where this capacitor is connected is complicated to me.  It is the same signal that supplies grid drive to the 6146’s, which is the same in both 32S’s.  But this junction is also connected to the neutralization circuitry and the tuned circuit parts of the driver.  Since the problem exists on all bands, I don’t think the driver tuned circuit stuff is a problem.  Driver voltages and the tube are good.Any ideas appreciated.Grayson, KJ7UM*** You are subscribed to Collins as k2fw@xxxxxxxx. If you wish to unsubscribe, or modify your preferences please visit https://mailman.listserve.com/listmanager/listinfo/collins ****** You are subscribed to Collins as n4kh@xxxxxxxxxxx. If you wish to unsubscribe, or modify your preferences please visit https://mailman.listserve.com/listmanager/listinfo/collins ***


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