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[N5XJT]

I purchased a used AL-80A (1990 mfr.) about 2 yrs. ago and so far very happy with it, no problems.  Output checked with 3 different watt meters so confident this is correct, around 850 watts CW and 1KW+ ssb with 60 watts input from either a FT-950 or a TS-850. The tube is a Chinese RF Parts 3-500Z about 15 yrs. old. HV is 2900 stand by, fairly steady under transmit. Question:  Is the 2900 HV indicative of a possible problem as the manual states it should be around 3100?  Just being over cautious, any thoughts appreciated.

[W1QJ]

HV is dependent on you line voltage and the condition and accuracy of the series resistors.  Most likely everything is totally fine.  Manual states a nominal value. YMMV.

[KD6VXI]

Hv is dependant on line voltage, as Lou said.

Metering accuracy is dependant on resistors installed in the 80s/90s....  Not sure when they went to the B model.

I found my Sb220 was very low HV.....  Or. So I thought.

Once I replaced all metering resistors my HV jumped up 400 volts!

--Shane
WP2ASS / ex KD6VXI

[KM4AH]

If it doing 1000+ with 60 watts drive there is nothing off about your voltage. Not, sure about your watt meter.

[W1QJ]

The watt “indicator” on this amp is NOT a watt meter.  It’s never exactly right at all and can be way off from a true value. It’s an TF voltmeter and usually calibrated on 20 meters into to a 50 ohm resistive dummy load.  It’s good for seeing a peak in output while tuning up but accuracy isn’t that good. 

[N5XJT]

Thanks for the replies, good info.  I never thought the built in watt meter was accurate so I verified output with three different external meters.  Sounds like all is well so will leave as is.  Thanks again.
Joe - N5XJT

[KM4AH]

Well, that's better than 12 dB gain. Which is really good.