-----Original Message-----
From: amps-admin@contesting.com [mailto:amps-admin@contesting.com]On
Behalf Of NI4L
Sent: 25 September 2002 10:53
To: Phil T.; amplifier reflector
Subject: [Amps] HV CAPACITOR BANK question
Phil
ok, let me ask you this ....the transformer i have is 3500/4500v@3.5
amps the gu84B likes about 4000v with a cap of that value 16@7500 v i
think was what it was? Would it ever fully charge? would it degrade the
performance of the amp by useing only one oil cap like this instead of a
cap bank like i have at 93mfd@ 7200v? Or would it be better to go with
say 2 of the 32mfd@ 4500v? what are your thoughts on this. I guess what
i am getting at is for all practical purposes which would make it sing
and what would make it lag? Another thing i was wondering... If by
useing the low tap on the transformer to keep the voltage around 4k
after running it through the caps and rectifiers will the transformer
grunt only useing the low tap and one oil cap. What would be a good
value of cap if you were going to use only one oil cap to make it work
smoothly? Anyone with any thoughts on this subject please step up to the
plate.
Chris
Chris are you actually running the GU84B at 4kV? The russian amateurs I have
talked to don't run it above 3kV ever. The GU78B which I have doesn't like
more than 3.5kV off load and the voltage ratings are considerably higher for
the GU78B.
I personally would not like 93mfd of capacitance in any big HT, that makes
for a lot of joules to get rid of in the event of a fault. I tend to go for
around 30mfd max in HT's of over 3kV, does anyone disagree with this?
Conrad G0RUZ
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