On Thursday 27 February 2025 12:55:16 pm wn4isx via groups.io wrote:
I'd have to dig through my "lab notebooks." All in 3 photocopy boxes filled with notebooks and sheets of paper. I'm recovering from bronchitis, my wife would have called 911 last Friday night if she hadn't had her knee replaced on January 31 and isn't quite up to managing alone, so don't want to breath the dust.
So, going from a 60 year old memory, something like shown
I don't much care for that site. They'd had a couple of my pages on there, and got takedown notices from me because of it. They want you to sign up to download, but taking a screenshot was good enough.
Note: This is not the way to do it today. Use CMOS chips to drive MOSFETs, lower loss from collector to emitter.
Good idea. I probably have more of those around here anyway. And a bunch of UPSs to acrap out, maybe I'll try and see what they're doing in one of those...
Tripplite used a similar design with heavy duty germanium power transistors in their 150W 12>120V inverter.
Hmm.
My unit almost certainly didn't produce anything near 60Hz, but it worked.
I'm not sure how important 60 Hz is for a lot of applications.
I'm amazed at how well a lot of my projects worked when I was somewhere beyond clueless. Of course a fair percentage were total failures. I tried to build a FM wireless mic....with a germanium transistor when I was 9. I didn't have a clue about Ft.
I never tried to build one of those. Closest I came to that was a device that was supposed to generate a signal that would be helpful in doing some TV adjustments, basically a few oscillators and a couple of monostables to move the lines around. The RF part was a lot of hassle. I had bought this thing as a kit, and ended up going to the place in NYC that was selling it, and the guy there was nice enough to fiddle with it some but eventually I just gave up on it. Not done much RF stuff since then.
Now the FM wireless mic with a pair of tunnel diodes did work, range about 500 feet. Yep, certainly violated Part 15 of the FCC rules.
I have a vague recollection of buying some tunnel diodes way back when, I might still have one, I'm not sure.
And my Tesla Coil got me in trouble when it sat the wallpaper on fire.... My mother disassembled that unit with a frightening amount of anger....
Heh.
I needed 90V one night RFN to check a surplus 6M military radio.
I was in Eastern Kentucky between Jackson and Hazard.
Sort of limited on options....but the grocery store (IGA) had 9V batteries.
I used 10 9V batteries, snapped the positive from one to the negative of the next. Ugly as sin, delicate as a ...er flower, but it worked.
I've seen that done before. But 9V batteries aren't as cheap as they used to be.
I've been told I think out side the box.
There are boxes we are supposed to think in?
Not that I'm aware of. :-)
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, ?a critter that can
be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters"
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Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin
