[Collins] 32 s 1 self oscilation

[Carl]

long with the other suggestions Ive tamed an unruly S1 and others with a 22 
Ohm 1/2W carbon resistor right at the grid pin of V-7 and a 100 Ohm 1/2W 
right at at Pin 8&3 with C58 at the tube side and C59 at the other and both 
with very short leads.

For the finals be sure R119/120 and R43/48 havent drifted high and as long 
as you are at it check the cathode resistors.Next install other 100 Ohm 1/2W 
carbon resistors at pin 3 of both tubes with added .01 discs at the far end 
as with V7.

Why Collins didnt use some of those basic stabilazation components across 
all S Lines is beyond me.

Also dont overlook a gassy 6AH6 or 6CL6 which would likely be running hotter 
than normal.

Carl
KM1H


----- Original Message ----- 
From: "Glen Zook" <gzook at yahoo.com>
To: <drleborgne at aol.com>; <collins at mailman.qth.net>
Sent: Friday, April 20, 2012 7:39 PM
Subject: Re: [Collins] 32 s 1 self oscilation


Neutralization! Follow the neutralization procedure in the 32S-1 manual.

Then, there are several things that can affect the neutralization:

Are you using 6146B/8298A or 6146W tubes or has the unit had those tubes in 
the final amplifier stage before? If so, has your 32S-1 had the 
neutralization circuit modification? If it has the modification then the 
neutralization capacitor inside the final amplifier cage will be an air 
variable. If it is a ceramic trimmer then there is a VERY good chance that 
it will "burn up" using the 6146B/8298A or 6146W and oscillations will 
occur.

Are you mixing an earlier 6146 or 6146A/8298 with either a 6146B/8298A or 
6146W. Doing so will virtually always cause oscillations.

In addition, tighten EVERY machine screw and nut that goes through the 
chassis. These do work loose and/or become corroded over the years. They 
need to be checked and tightened every few years.

Glen, K9STH


Website:  http://k9sth.com


________________________________
 From: "drleborgne at aol.com" <drleborgne at aol.com>
To: collins at mailman.qth.net
Sent: Friday, April 20, 2012 9:45 AM
Subject: [Collins] 32 s 1 self oscilation


Dear collins colleagues: My 32 s-1 seems to self oscilate consuming 
transmitter power in the bands above 7.2 Mg.
Any suggestions where the problem might be ? thanks & 73 KI4JRY   Martin
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