On Sun, 02 May 1999 10:03:47 -0700 Vic Rosenthal <rakefet@rakefet.com>
writes:
>
> I've got just about all of the parts for my 2 x 3-500z amplifier
> except the
> plate transformer. I haven't been able to find one of reasonable
> size and
> weight inexpensively, so I'm thinking about buying one from Dahl.
Inexpensive and Dahl do not work in the same context.
> My question
> is: should I get a transformer for a doubler or full-wave bridge
> circuit?
A doubler in SSB/CW use offers a significant advantage over a FWB. Been
explained here too many times to go into that again.
I
> was planning to use a doubler and one of the SB220-replacement type
> of
> transformers, but I realized that if I'm actually going to buy a new
> one, I can
> get whatever I want. I already have 8 240uf 450v electolytics for
> the filter; I
> can use them in either configuration.
Good values as long as they can handle the ripple current. Cheap bargain
caps are a potential disaster.
>
> I want to run the amp at 3000v. Would a bridge circuit provide a
> stiffer plate
> supply?
Not at those cap values. For intermittent service such as SSB/CW the
doubler can actually be more efficient since it uses a larger guage
secondary wire; assuming equal KVA ratings of course. There is a lot to
be said for using capacitor storage in some applications.
>
> Also, I need a pair of 3-500z chimneys. Somebody had a pair for
> sale, but I
> can't find his message. Anyone?
Ameritron uses a cut down version but they work and are cheap. BTW,
unless you are pushing for lottsa RF out a chimney is not a
requirement....good airflow is. Buy one of Harbach's high volume SB-220
fans.
>
> 73,
> Vic, K2VCO
> Fresno CA
>
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>
>
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