[Boatanchors] Re: [Hammarlund] Johnson Electronic T/R Switch.

[Peter Markavage]

The ones I have use a 6BL7 and a 6X4. If you want to cut down on some of
the heat, replace the 6X4 with a pair of diodes.

Pete, wa2cwa
http://www.manualman.com

On Mon, 19 Feb 2007 14:36:50 -0000 "Ken Hickman" <n5cm at rtconline.com>
writes:
> Hi Gang,
> 
> I obtained a Johnson T/R Switch, Catalog No. 250-39 about a year 
> ago.
> Haven't had
> a set-up to use it until now.
> The case get too hot to touch after a short time on! I used one many 
> years
> ago and
> although it got pretty warm, I could pick it up.
> I seem to recollect the gating tube was a 12BL7. This one which 
> looks almost
> new
> has a 6BL7 in it.
> Anyone have an manual and/or schematic? Help!
> Take care,
> 
> Ken   N5CM