[Milsurplus] LV Tube operation.... was half-voltage dynos

[J Forster]

  Hi All,
    The November issue of Electric Radio has an article on a vacuum tube

  curve tracer.This looks like a useful tool if you are into design.
    In tech school we had to generate characteristic curves for each
half
  of a 12AU7, create the transfer characteristics and then build various

  configurations of small signal amplifiers.We just had power supplies
  and meters all cliped together,but it was fun if you only had to do it

  once!

Curve tracing is easy if you have access to a Tektronix 575, 576, or 577
Curve Tracer. All you need is a filament supply and socket wiring if you
are interested in Triodes or Diodes. Things with additional supplies
require extra stuff.


    Anyway,the setup in the ER article may be the ticket to look at what

  happens to the tube characteristics as a function of filament voltage
  and effective heating of the cathode.
   Jay KE6PPF

I got into studying cathode poisoning because of my interest in
reconditioning gassy tubes. It can, in fact, be done quite easily in 80+
% of the WW II small signal, not transmitting, tubes.  It saves having
to realign sets.

-John