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Ameritron question on unit I purchased

NightOwl3261

Well-Known Member
Jul 24, 2020
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Purchased a used but very clean AL-80p and the unit has what looks like nice professional tags under the meters that say.

Under one meter it is tagged:

IG 150ma
IP 400ma

Are these max settings to stay at or below?

Under other meter it is tagged:

ALC140 ( have no idea about this one)

Been years since I tuned a tube amplifier.

Do these values mean anything to me?

Also if need be, after a ten meter mod on the amp, with a modern HF rig can one just use the radios internal antenna tuner to match the impedance of the radio to the amp rather than the tuning slug on the back of the Amplifier?

You can use AM unmodulated to tune and don't need to use CW correct?
 
Last edited:

W8JI, the designer of these amplifiers, says adjustment of the tuning slugs is unlikely to be necessary, and to avoid messing with them.

Your radio probably doesn't make enough power in unmodulated AM (~25W) to tune an AL80B to full power. Tune in CW or FM, start at a relatively low power then work your way up. I believe W8JI has his recommended tuning instructions posted on his website.

Found it: https://www.w8ji.com/loading_amplifier.htm
 
Digging deep in my old grey matter..
The al811 & 811h mod is SIMPLE. you cut 1 wire for the 10-12 meter mod, you will need to adjust input coil (inside amp)for lowest swr. if you do for 26.700 mhz, center of 24.900 & 28.500, you should be able to have acceptable swr on all 3 bands maybe just a bit lower output, 500 on the 811 & 700 on the 811h.
unless you use a real ham rig with mating cables, you'll need something to key it.
Adjusting the coil watch for high voltage inside the amp...
P.S.found a thread on this forum about it read it good info there.
Don't try to beat the snot out of the amp, tubes are expensive and almost onubtanium now...

Ameritron AL811 | WorldwideDX Radio Forum
 

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