I'm designing a dual voltage HV power supply and am ready to order the plate
transformer. I'm a bit unsure about the best choice of voltage ratings,
however. One primary tap of the transformer would be suitable for three
3CPx800a7 tubes. For that tap, I'm thinking I'd like a no-load (except for a
100K bleeder) DC voltage of 3650V, which would drop down to about 3300V at
1.8A. (That would correspond to a transformer secondary of 2600Vrms.) Does
that seem like a reasonable choice for the 3CPX800a7? Obviously I can go up
or down, if necessary.
The other winding would be for three 3CX800a7s or GU74Bs, and here I'm
thinking a no-load voltage of about 2800V, dropping to about 2500V at 1.8A.
I know the original specs for the 3cx800 specified a maximum plate voltage
of 2250V, but that was subsequently increased to 2500V. I hear conflicting
stories about the maximum voltage for the GU74B, but most folks put it at
about 2500V. I'm not sure how much I can push the voltage rating on the
GU74B. In any case, I'd appreciate opinions on the subject.
Thanks,
Jim W8ZR
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|