[Hallicrafters] Cleaning the inside of HT33A amplifier

[Richard Knoppow]

----- Original Message ----- 
From: "John King" <k5pgw at yahoo.com>
To: <hallicrafters at mailman.qth.net>
Sent: Tuesday, November 08, 2011 5:37 AM
Subject: [Hallicrafters] Cleaning the inside of HT33A 
amplifier


I am mainly worried about the transformers because they are 
NOT POTTED.

     That may actually make them easier. A million years 
ago, when I worked for Hewlett-Packard, we routinely washed 
instruments. We found that supposedly hermetically sealed 
transformers and chokes often failed because they were NOT 
very well sealed, small amounts of moisture could get in but 
didn't come back out during the baking process. We routinely 
removed such transformers. Open frame transformers will bake 
out thoroughly. Our drying process used an electric oven 
running at about 130F and a minimum of 48 hours. I preferred 
to leave stuff in for a week if possible. I _never_ had a 
transformer failure in nearly ten years of doing this.


--
Richard Knoppow
Los Angeles
WB6KBL
dickburk at ix.netcom.com