[TMC] FRR receivers and testing 4CX tubes

[doxemf at aol.com]

Hal,

For testing some of the common 800 series tubes, 811,12,13,14, and 
4-65/125, etc., I built up a small multisocket chassis around a dual 
6.3v ct transformer with a terminal strip breakout to be replaced with 
a switch someday. A small variac servers as the fine adjust.

  A 1 kv @ 250ma CV or CC variable regulated supply for the plate and an 
Eico 1030 supply for screen and bias gives me enough parameters to 
pretty much setup a good quality test.

 It really weeds out the shorted, overloaded screen, and gassy tubes.
You can use a known new or good working tube to establish a "normal" 
range of readings and go from there.

Using the CC, Constant Current mode prevents any blowups and really 
lights up a gassy tube.
   I set up a 100ma limit and then adjust the bias voltage to achive 
that with a KV on the plate.
Tube manual parameters can also be used for most of the tubes.

  This supply is an Electrophoresis medical lab type which can be found 
reasonably on e-bay.

Hope this helps,
Bill,
KB3DKS/1


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