[Amps] Voltage Doubler Regulation

[k7fm]

"## I have 3 x drake L4B's  and  mating hv supplies.  2650 vdc on RX..
and  2500 vdc  with 800 ma  key down cxr.  They use a doubler.  The
xfmr is a small thing. Sec dc resistance is 10 ohms.   They used  8 x 200
uf caps.  I replaced em with 8 x 2500 uf  outboard caps.. [ and step start 
of course].
Dynamic regulation is superb on ssb... it doesn't budge.  Ripple dropped 
from
 3%...down to just .24% "

I had the same transformer Dick had.  The transformer is in a BTI-2000.  It 
is large and heavy and I figured it should have better regulation.  Without 
doing much testing, I installed lots of C, but it did not help.  Then, I 
learned the truth - the secondary was fairly high resistance, even though it 
was designed for a voltage doubler circuit.  If the resistance is high, you 
can add all the capacitance you can find and not solve the problem.

73,  Colin  K7FM