> From: Rich Measures <measures@vc.net>
>
> For adding a step-start relay and high speed switching, a FWB is
> indicated. Half-wave rectification causes DC to unhappily flow in the
> transformer. Adding 3 more diodes and ungrounding the 80v winding is
> easy/inexpensive.
The very small power demand of the bias supply (about 12 watts)
would not greatly affect the core losses of a transformer already
delivering 160 watts to a resistive load.
The half wave rectifier is perfectly fine.
If I was going to do a mod, I'd get rid of the whole 130 volt supply,
and let the tube self-bias off. Than a more conventional 12 volt
relay could be used.
Not doing a 12 volt conversion, why bother with a full wave bridge
change. The switch to a FWB would not make a bit of performance
difference.
73, Tom W8JI
--
FAQ on WWW: http://www.contesting.com/ampfaq.html
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|