[R-390] 26Z5W replacement

[Tim Shoppa]

> Has anyone tried rewiring the rectifier scoket and
> using another rectifier tube in its place instead of
> going solid state and wiring in a resistor?

Somewhere on the net is descirbed how to use 12BW4's
in place of 26Z5W's.  You have to put the filaments in series
instead of parallel.  12BW4's are readily available.

Ah, here it is:

  http://www.mines.uidaho.edu/~glowbugs/r390_psmod.htm

Looking in the mailing list archives it is reported that the 12BW4
has slightly higher plate resistance than the stock 26Z5W's.

Tim.