[R-390] RT301 current regulator tube

[Jacques Fortin]

Hi all,
I just found the V-I plot I made in 1984 from the 2HTF11B that came with my
R390/URR when I found it.
For the record, the Amperite 2HTF11B is a functional equivalent of the 3TF7.
And for the sceptic ones, look at the TM 11-856, page 12, figure 11.
At that time, it was right on the 300mA target between 10 and 18V.
I will attach the pdf, but not sure it will "pass".

And about beating that dead horse: Dallas Lankford already published in 2004
that the best BFO + PTO stability was obtained by powering the filaments
with a voltage regulator (he used a 7812, I believe).

73, Jacques, VE2JFE in Montreal
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