> 1-These amps are notorious for parasitics. EVERY ONE OF MY AMPS WAS
> FITTED OUT WITH the Ralph Measures 3-500z parasitic suppressers
You just said two very dirty words, Tom will now proceed to try and castrate
BTW, my LK500ZC has many many hours behind it including several ARRL and CQ
DX and WPX contest awards. I never once had a "parasitic" problem or lost a
tube since it was new in 1987. It has also tuned just fine into 3:1 and
> had no further problems--for 10 years, in every cqww and arrl test
> during those years. I replaced just two 3-500z tubes in all that time.
> 2-Some of these amps have a low and a high fan setting. I always used
> the high fan setting. There is also a temp sensing circuit which
> switches the fan to a high setting with a higher duty cycle. If this
> cicuit is not working that may be your problem..
> 3-The amps I had all were fitted with four fans in a wall behind the
> tubes. Check that they all work. Also note that the fans are usually
> very, very noisy on the high setting. If the fan noise is very quiet,
> then the fans are NOT working at the high rpm setting.
> 4-If you are running the amp at the 3500 dc high volt tap instead of the
> 3100v tap on the xfmr(just switch to the high voltage indication on the
> front panel, no load) you will have tuning capacitor arcing and
> bandswitch arcing problems on any load other than 1:1 SWR. This amp is
> not designed to operate at power levels of 1500w at other than 1:1.
> My amps ran well at 1200watts into loads up to 1:3 SWR.. I ran all
> of my amps at 1200-1300w MAX into low swr loads for years at v47kp
> without problems.
> If you insist on getting 1500w out, good luck!!
> 5-Drive power was limited to that which gave 1200w out, typically 70-100
> watts depending on the band.
> 6-I never ran the amp with the full break in system.
> alex aimette, w2ox/v47kp
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