[SPAM] [BITX20] LTSpice simulation of uBitx Power Amp
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Jerry… thanks for doing this. I had intended to do this same thing but so many things kept getting in the way. Since you uploaded the .asc I’ll try some of my favorite PA transistors in place of the 510s when I get back from vacation and see how they look. The 3904s should be good above 50 mhz. also I suspect the stages are coupled a bit too tightly at higher frequency where something smaller would be more appropriate. Anyway, nice work.
This does point out a few “oh yeah” things though. The 510 miller cap loading at the higher frequencies is very high. I guess you see that in the smith chart of the spec sheet too so no surprise. Also, I think we see a lot of variation in the 510 parts…as some people report them working well at 20+ MHz and some not so much.
Yes agree. I’d love to see a sim of the WA2EBY amp. Dying to know the efficiency at 30 MHz.
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From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Jerry Gaffke via Groups.Io
I've uploaded an LTSpice simulation of the uBitx Power Amplifier from Q90 on out through the IRF510's