COLIN LAMB wrote:
I do not want to discourage you from changing things - but the regulator
tubes are quite reliable and are also a visual indicator of high voltage.
They will have exactly the same heat and power usage as zener diodes, so
there is no advantage to use them.

I will say that the regulator tubes in a lot of equipment is problematic
because they are noise sources that spew RF trash all over the place. In
the Hammarlund sets they are well-shielded and decoupled at the base, but
it still would be interesting to compare receiver noise floor with and without
a zener string.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."