[Milsurplus] 1625 Tube Base Hole

[WA5CAB at cs.com]

That's right.  I think it was only one or two contractors who brought the 
cathode and suppressor leads out of the envelope separately, like in the 837.  
But I don't recall who they were.  Probably shown in the '56 HB article (which I 
don't have here).

In a message dated 3/12/2006 6:15:05 PM Central Standard Time, 
kgordon2006 at verizon.net writes: 
> >     I have several 1625 tubes with a 1/4  by 1/2 inch hole cut in the 
> side 
> >of the base
> >right above pins 5 and 6.  Could someone explain why this was done.
> 
> Yes. Those cuts were made to enable separation of the suppressor grid 
> connection from the cathode connetion so that those tubes could be 
> used in a grounded-grid linear amp.
> 
> SOME 1625s had a separate EXTERNAL connection to the suppressor 
> grid, and that connection, and the one to the cathode were stuffed in 
> the same pin and soldered. Most 1625s had the suppressor connected 
> to the cathode INTERNALLY, i.e. inside the tube envelope.
> 
> 

Robert Downs - Houston
<http://www.wa5cab.com> (Web Store)
MVPA 9480
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