I kinda had the feeling that someone would suspect poor line voltage
regulation as a cause of the secondary DC voltage to sag heavily. I was
going to mention that it was the first thing I checked. When I originally
built the supply I had 25 amp fuses but I blew them to kindom come in a few
seocnds of key down loading. I took care of that, and continued my
investigation, I determined that under no load and a HV DC of about 4300-4400
volts being produce by a line voltage of 238 volts. At full load I measured
the line voltage and it dropped to 229 volts, thats not bad since the line
current is about 45 amps. So the problem is NOT primary line sag. Bill Orr
claims in his book, that the regulation of the DC from the rectifier is much
tighter when the increase in filter capacitance. Like I said he recommended
80uf for my specs. I had 120uf and did not get the 5% regulation he talked
about. I know that all power supplies drop considerably when loaded heavy
but this supply has all the goodies to prevent that. I am leaning towards
the theroy that since the secondary AC voltage on the transformer is 3000,
that is the effective voltage and will be the only "heating power effect"
voltage. The 4300 volts after the rectifier is 1.414 of the 3000, but that
is the peak of the 3000, and the peak will not offer any effectiveness to the
"heating effect" so a voltage drop should be expected near that 3000 vac
value. Also, since SSB has become popular nobody uses choke input filters
any more. Now as I recall you dont get that rise in voltage with a choke
input filter. So maybe I should count my lucky stars I have a few hundred
more than the effective 3000. So what say anybody?.....73 LOU
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