[Hallicrafters] 1000 kc crystal tube

[rbethman]

Bob,

We ran across similar "modules" while still in the military.

There were several in our JCS 750KW Solar Gas Turbine generators.  There 
were also a couple in the switchgear skid built by A.G. Schoonmaker.  
They had two versions.  One for three 500KW generators, and another for 
four 500KW generators.

Having had several failures and ridiculous replacement costs, we also 
had nothing to lose.  So off we went tearing them apart.  They were P&B 
Relay cases, but were internally a circuit of diodes in one case.  We 
made our own for FAR less than ordering the replacements.

The others were like you described, a relay and a handful of diodes.

Same solution!  Built our own.  Saved Uncle Sam a pretty fair chunk of 
money!

Looking back, we probably could have submitted our solution in hopes of 
getting a financial award, but honestly we were just trying to keep the 
equipment working.  That was our focus.  If money was driving us in the 
'70s, we would NOT have been in uniform!

Bob - N0DGN

On 2/26/2010 1:27 PM, Robert Nickels wrote:
> On 2/26/2010 11:31 AM, springertool at wyoming.com wrote:
>    
>> I ran across an interesting "tube" recently among my boatanchors .. a triple AND gate inside a metal, 11-pin tube ... albeit, diode logic, it shows the evolution of technology.
>>
>>      
> Very interesting indeed, Jon.   Back in the late 60s, my ham buddy and I
> scrounged some modules out of the trash of a company which was known to
> have it's own 'mini-computer'.   They were encapsulated in epoxy with an
> octal type plug (can't remember how many pins) so figuring there was
> nothing to lose I turned my dad's propane torch on one, and found that
> the epoxy would soften to the point it could be picked away in chunks.
> Inside was a 12 volt Potter-Brumfield 4PDT relay and some diodes and
> resistors wired in unfathomable (to us!) ways.  We did find good uses
> for the relays but I wish I'd kept a couple of the modules now.
>
> 73, Bob W9RAN