I suspect the tuned inputs are just too out of resonance to pass all
the drive on the WARC bands. Does the output power keeping increasing
as you increase drive until you run out of drive? If so, then my
hypothesis is probably right. My SB220 input networks aged to the
point where I had this problem on the regular ham bands, much less on
the WARC bands. I'm rebuilding the tank and input circuits to include
the WARC bands.
Michael
--- Bert Almemo <balmemo@sympatico.ca> wrote:
>
> Thanks for all your answers and shared experiences re. my problem
> running my
> SB-220 on the WARC-bands. All of your amps seem to be doing fine, but
> unfortunately not mine.
>
> Power out on 12 and 17m is around 400W and 30m doesn't really work at
> all.
> The reason for the low output, compared to all of you who answered
> (most of
> you have over 1KW out), I don't know. Are the tubes tired or do I
> have too
> little driving power. The IC-765 only delivers 90-100W and that, I
> know, is
> not enough to drive 2x3-500Z to full output. The output from the amp
> is
> anywhere from 600-900W depending on band, 10-80M.
>
> Any ideas of how to find out if the amp is healthy, tubes OK, etc?
> Appreciate your input.
>
> 73 Bert, VE3OBU
>
> _______________________________________________
> Amps mailing list
> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
__________________________________________________
Do You Yahoo!?
Yahoo! Movies - coverage of the 74th Academy Awards®
http://movies.yahoo.com/
|