On Fri, 5 Oct 2001 12:02:52 -0700 (PDT), Jim Reisert wrote:
>The HF-2500 is extremely sensitive to grid current. 5 or so years ago, we used
>one in an SSB contest at KC1XX and the thing shut down on a frequent basis.
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I've run my HF-2500 for about three years now and the only time it shut
down was from pilot error. At 1500 watts out, normal grid current in
mine is about 30-40 ma. The grid protection circuit trips at >100 ma.
If yours was shutting down for no apparent reason, there must have been
some kind of fault in the amp or antenna system. The factory claims
"brick-on-the-key" performance on all bands, no time limit, no
exceptions. That's just what I've seen with mine.
A great amp, IMO. I prefer it to my previous Alpha 91b because:
1. I like triodes over tetrodes. They tune better IMO, because the
interaction between screen current and plate current makes tetrodes tune
up a little strangely. The various peaks and dips do not all coincide
like they do with triodes.
2. It has real analog meters instead of LEDs. The LEDs do the job ok,
but I just prefer real meters. I guess I'm just an old fashioned guy.
The 91b does have one advantage; it has separate band switch positions
for all the WARC bands. The HF-2500 doesn't.
Bill, W7TI
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