Doug Person wrote:
>
> That seems quite a bit less than what the manual suggests. However, the
> reduced power would hardly be noticable to anyone. I wonder what the
> affects of SSB would be rather than full carrier. If I tune up the amp
> using no more than the 400ma plate current and 65 watts drive, would pushing
> the power to 100 watts PEP input during normal SSB operations result in
> additional stress on the 3-500z, or perhaps increase distortion?
The single 3-500Z can be tuned and loaded to 550ma single tone (CW) for a very
short period in order to establish the correct operating conditions for the peak
of the SSB signal. It should then be driven by no more than about 65w PEP to
give about 1000w PEP output. Average plate current will be much less than 550
MA. However, when operating CW, the amp should be loaded to 400 MA maximum! I
find that my SB1000 produces around 800 watts CW output with 400 MA plate
current and around 125 MA grid current.
> Now that I've gotton your input, I'm sorry to report that while tuning the
> AL-80A on 17 meters with 500ma ip and 150 ma of ig, A somewhat loud and most
> unpleasant noise ocurred within the amp after which there was no current
> indicated for either ig or ip. Did I fry the tube?
You probably fried the plate RF choke which has a resonance near 17 meters. You
can order a replacement from Ameritron for about $25. The one made for the
AL80B works properly on the WARC bands. I have had one of these in my SB-1000
(which by the way is *very* similar to the AL80) for some time and it works
quite well on all bands, including WARC.
73,
Vic, K2VCO
Fresno CA
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