Wednesday, September 9, 2015

BAM! - AL-80A Broken Again

Well, crap. The AL-80A is broken again. Yup. I was on 17m chasing a bit of DX, when I decided I needed more than 100 watts. I hit the A->B button, then A/B, then tuned a bit away from the DX frequency (never tune up on DX - ever), dialed in 50 watts, switched the amp to operate and hit the Tune button.

Heard something go POP! as I turned the plate tuning knob, and immediately the grid current meter pegged. Not good.

A little diagnoses -- with no RF, keying the amplifier the grid current meter reads about 100 mA. Even with about 20 watts, the grid current meter pegs. Seeing the output meter peg, too.

At the worst, I may have fried my tube. I suspect I may have blown more of the metering circuitry.

This amplifier is very picky about 17m....

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