I have a Trans World Electronics 500M with 8 Motorola MRF 454 transistor
finals. I was playing around the other night with my K2 qrp rig keying about 8
or 9 watts into the amplifier. It amazed me how well it was working as I was
getting an easy 100 plus watts and it seemed like I was still enjoying the qsk
of the K2.
Unfortunately, I put my hand on the heat sink and it was hot. Usually on ssb
it hardly gets warm even with the occasional rag chew. I looked at the amp
meter and the collector was drawing 20 amps with no rf input. I quickly shut
things down. The next morning I popped the cover just to give a visual
inspection. There is no apparent physical damage nor burnt odor.
I put 50 or 60 watts of ssb rf into it last night and the amp easily put out
over 500 watts drawing 70 amps on peaks. But,again, once the mike was keyed it
drew 20 amps without any modulation.
I am really not much of an electronics tech but open to any advice, comments or
trouble shooting tips anyone may care to share. Or if there is a repair
service that will work on a Metron. I hate to toss it out as I seldom need the
500 watts but its the only way I will get on 75 meters in the evening.
Meanwhile back to cw qrp with the good old K2.
Thanks for reading, Larry W8CCY
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