KPA500 FT8 on 17m anomaly

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KPA500 FT8 on 17m anomaly

mtwheatley
I have a FlexRadio 6400 driving my KPA500 with a 43' vertical antenna and an
MFJ-988RT tuner at its base.  I do a lot of FT8 on different bands,
Everything works great on all bands except 17m.  There if I run the
FlexRadio barefoot at 80w, everything is fine.  But if I turn on the KPA500
and set the output from the Flex to 15w, when I key FT8 the output of the
KPA500 jumps around wildly between 80 and 150w when it should be about 250w
steady.

This only happens in DIGU (digital mode).  If I switch to FM or NFM on the
same frequency the KPA500 operates correctly and its output is about 250w.

My SWR on the band is 1.2

Any ideas?

Michael - KM6LHD



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Re: KPA500 FT8 on 17m anomaly

mtwheatley
Thanks to Bob, K4TAX, I found my problem.  It was RF on the short cable
between the remote tuner and my 43' vertical antenna,  Some good snap on
chokes fixed the problem.

MIchael KM6LHD



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