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@hotmail.com>
To: <amps@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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