I participated in the design of Ez-Em, a medical device. That's all I'll say about that.
I did invent a company, Simple Systems Inc, so I could get the free electronics magazines, back when they were worth getting.
I used to take the St Charles line streetcar to Radio Parts on Lee Circle in New Orleans. Giant statue of Robert E Lee, with his back to the north. More often than not, they would give me parts. Once the owner gave me a 10-turn pot and dial, which overwhelmed me. Probably nobody else in New Orleans wanted it anyhow.
Mike Quinn Electronics, in a quonset hut at the Oakland airport, was a death trap.
All the surplus places are gone around here. There used to be one on Market Street in downtown San Francisco.
--
John Larkin Highland Technology, Inc
Science teaches us to doubt.
Claude Bernard
h RCA's 40673 that was used in TV tuners and garage door openers. They used to cost me 36 cents, from the Linear corporation that built the openers. I bought them 25 at a time, and often ran out before more were available. Th ese were very sensitive receivers, and with careful alignment many would op erate a door from three blocks away. That was handy for fire stations. They could start the doors to open and have them open enough that they didn't h ave to wait to pull off the road when they returned after a fire run. the 4
06743 turn up in small batches from time to time, but they aren't worth $20 each.
e
led SREPCO, and it carried TV repair parts. Pioneer had an industrial branc h in Dayton, Ohio but they only sold to corporations listed on Dunn and Bra dstreet. SREPCO was a very early distributor in Electronics 'Standard Radio and Electronic Parts Company'. Those stores were closed, decades ago.
.
"
Dayton had several surplus stores, including the infamous Mendelson's which was started at the end of WW-II buy buying the leftover parts as war contr acts were terminated. Lima Ohio had the well known Fair Radio. All in all, about a dozen surplus stores within a four hour drive. My first visit was t o Mendelson's while I was in High School. I was teaching a night school cla ss for adults in 'Small Appliance Repair' and one of my students offered me a ride. We were there until they turned out the lights. MPJA was supposedl y the infamous 'Jonesy' who had a store in Dayton in the early '70s before moving to Florida. A less well know shop was Mike Bird's. It was above thei r family coin and trophy shop, and by appointment only. I had to teach him how to price things at Hamfests. In return, he offered to let me have credi t on what I wanted. He would also give me stuff he didn't think would sell. Like a case of over 900 nine pin tube sockets. I went there one day. For $
100 I bought a 60W Bogen MX60A PA amp, a pair of short racks with a desktop from a PDP8, and a GE band printer. Two days later my boss said, I sure wo uld like another of these Bogen MX60A PA amplifiers. He gave me $100 for it . I still use that PDP set of racks as my main workbench 40 years later. :)
Yeah, they knocked down Radio Row on Canal St to build the WTC.
Dave Jones has a video of a place in (iirc) Burbank that has all sorts of old missile parts and stuff.
Apart from the nostalgia value, we're way, way better off now.
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510
http://electrooptical.net
http://hobbs-eo.com
I had to lookup the electrolyic transistor. What's the reason these odd devices went away? I get the point contact diodes and transistors are just obsolete, but since when are zeners going away?
Has anyone here used any SiC power semiconductors?
One of the oddest is Ge(Li) diodes. Called 'jelly detectors', they had to be kept cold (liquid nitrogen temperature). Continuously. Not just in operation, but all the way from the factory to the point-of-use.
And, of course, the selenium drum in the old Xerox machines is an odd semiconductor.
Lithium-drifted silicon [Si(Li)] and germanium [Ge(Li)] are ancient history--they went out about 1980, when boules of higher purity became available.
The lithium drifting was intended to make them behave more like intrinsic semiconductors.
If a Ge(Li) detector warmed up, it decayed with a time constant roughly like fresh fish. It could be re-drifted once, with some performance degradation, but if it happened twice it was toast. Fortunately intrinsic Ge detectors are tougher that way.
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510
http://electrooptical.net
http://hobbs-eo.com
Expensive, unreliable, slow, big, noisy. You can put a lot of BCX70s on a 6" wafer.
I get the point contact diodes and transistors are just
Bandgaps are better at low voltages, but zeners are still popular.
I've used SiC diodes and the Cree and ST power fets. They are fabulous at high voltages, but hard to drive. I'm driving one from -8 to almost
+20 on the gate in a few ns, and there are no commercial drivers that will do that.
The 1200 volt Cree parts sort of zener around 1600 volts or so on the drain, without damage. But you can blow out the gates driving them a little harder than you need to.
The Cree substrate diode model is a joke.
--
John Larkin Highland Technology, Inc
picosecond timing precision measurement
jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com
They're dramatically faster and tougher, for one reason.
Are there any good MOSFET substrate models?
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510
http://electrooptical.net
http://hobbs-eo.com
with RCA's 40673 that was used in TV tuners and garage door openers. They u sed to cost me 36 cents, from the Linear corporation that built the openers . I bought them 25 at a time, and often ran out before more were available. These were very sensitive receivers, and with careful alignment many would operate a door from three blocks away. That was handy for fire stations. T hey could start the doors to open and have them open enough that they didn' t have to wait to pull off the road when they returned after a fire run. th e 406743 turn up in small batches from time to time, but they aren't worth $20 each.
You
ly
100
-the
called SREPCO, and it carried TV repair parts. Pioneer had an industrial br anch in Dayton, Ohio but they only sold to corporations listed on Dunn and Bradstreet. SREPCO was a very early distributor in Electronics 'Standard Ra dio and Electronic Parts Company'. Those stores were closed, decades ago.
ted
,
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n
Not for you, but the warehouses that Amazon fills with people are breeding grounds for the virus. Many employees have quit and when employees speak o ut about better working conditions they get fired. I seldom use Amazon bec ause there are always better alternatives. Amazon is the easy choice for p eople who don't like to think.
--
Rick C.
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