[R-390] Gettering old tubes

[Drew P.]

Ben Loper wrote:

"This is probably getting out of hand but maybe put together a chassis with
multiple sockets and a filament supply to keep your tubes warm"

I got one! It not only does that, but also applies conservatively rated bias voltages to the other tube electrodes to avoid cathode interface problems.  It is enjoyable to operate and is an electro-mechanical marvel.  It's called an "R-390A".

Drew