[Amps] Vintage Bandswitches; for Homebrew

[Carl]

They were part of the BC-375 tuning units used in those WW 2 planes.

There used to be an endless supply of those switches decades ago, even a 
commercial ham amp used them. Ive several myself.

They will work fine in an amp of reasonable power but realize they are 
nonshorting. I dont know what the breakdown voltage is and how much 
contamination the ceramic has accumulated in the past almost 70 years or 
so.

Carl
KM1H


----- Original Message ----- 
From: "Pat Barthelow" <aa6eg at hotmail.com>
To: <amps at contesting.com>
Sent: Saturday, February 07, 2009 12:10 PM
Subject: [Amps] Vintage Bandswitches; for Homebrew


>
>
> Since I was a kid, I usually had in the junkbox (garage)  WWII vintage 
> QRO parts and various boxes.   There were lots of various tuner boxes 
> that I later learned were often installed in B-17s and other bombers. 
> The construction was MASSIVE, but a bit crude, at least 
> cosmetically... no Silver plating, and dainty precision formed 
> contacts here.  There was a common bandswitch in a tuner that I found 
> a crude picture of on the web:
> http://www.pa6z.nl/PROJECTS/136KHz_trx/a_Resize_of_band_switch1.jpg
>
> That had large, heavy contacts, and wipers,  heavily tin plated, and 
> massive ceramic structures.   Simple plain, large, but robust.  Are 
> there any plusses or minuses that folks have exprienced in using this 
> switch in a home brew QRO amp?
> Best,
> Pat, AA6EG
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