[Hallicrafters] 1000 kc crystal tube

[Troglodite at aol.com]

In a message dated 2/26/2010 12:28:00 P.M. Central Standard Time,  
ranickel at comcast.net writes:

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.



Bob,
 
It seems there was an era where everyone got into the "modular" act. There  
was something appealing about it at first. It made replacing blocks of 
circuitry  simpler, and some systems using multiple copies of same or similar 
circuitry  seemed to lend itself to the idea.
 
I used the concept on my second homemade electronic musical instrument,  
about 1967 or so. I made 9 pin bases by setting 9 pin tubes in a pie pan and  
filling it with about 1/2" of melted wax. I then yanked the tubes, and  
straightened and cut pieces of #18(?) tinned solid wire which I placed in the  
holes vacated by the pins. I then filled the cavities with polyester resin,  
casting about a dozen 9 pin "plugs" at a time. I built the circuitry on to  
these, then glued the result into a pharmacy bottle. It was cheap, and 
looked  reasonably decent.
 
It would have been nice if Compactrons had been around then, I could have  
done the same thing but had a couple more pins. For most of my modules, 
which  were simple flip flops, preamps and analog filters, 9 pins was sufficient.
 
Doug Moore kb9tmy