>
>>..... For intermittent service such as SSB/CW the
>>doubler can actually be more efficient since it uses a larger guage
>>secondary wire;
>
>? good point. . . IOW more copper and less paper.
>
>But isn't the transformer utilisation factor worse with the doubler, leading
>to higher peak currents, and so more loss? OK, so resistance is less, but
>loss is I squared R. This makes the choice more difficult.
? So it would seem. . However, the decrease in R with half as many
turns required is better than what one might expect since fewer layers of
paper lets one use a bit larger gauge of wire than would at first seem
possible. Thus, utilisation increases with a doubler design. //
Another advantage of the FWD is ripple semi-cancellation -- i.e., as one
capacitor bank is discharging, the other is charging.
> think I'd go
>for the bridge because of this...but I prefer the tuned choke input with the
>bridge to reduce strain on the tranformer and rectifiers.
>
? And especially for RTTY and AM broadcasting duty. // With a tuned
choke filter, FWB is the only reasonable choice.
>
- cheers, Peter
Rich...
R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures
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