Maybe you'll be dead...:^) or maybe someone else will pick-em up? I think we're still buying RF power transistors from Russia or somewhere... ~70 MHz at 1-2W. (70 MHz is my freq, I don't recall where they roll off.)
So one would have to parallel BFT93s, then. Blech.
I ordered a reel of BFG403s (basically a 17-GHz BFT25A), which are on LTB, and am plotting to get some SKY65050s, ATF38143s, ATF55143s, BFP640s, BFP650s, BFU520As, and a few others that are still apparently in production. Ties up a few $k in inventory, but preserves freedom of action and possibly future competitive advantage.
Inconvenient.
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics
160 North State Road #203
Briarcliff Manor NY 10510
hobbs at electrooptical dot net
http://electrooptical.net
Or maybe buy 20k, at less than $0.50/ea that could be a nice investment if you end up not using them. It is likely that obsolete parts dealers come banging on your door who are then willing to pay 5-10x that money. I just had a situation like that but could not help them because I didn't know any former clients who had stock in the part left.
One approach when you don't need wide range fast slewing is an NPN connected as a pseudo-inductor (resistor from C-B, cap from B-E). It's good for stiffening PNP current sources. Of course the limited slew range probably leaves out every single one of your applications. :(
Tubes have a similar problem, for similar reasons. ;)
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics
160 North State Road #203
Briarcliff Manor NY 10510
hobbs at electrooptical dot net
http://electrooptical.net
However, tubes have a staunch constituency and the Russians and Chinese have figured out how to cash in.
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Even very cool looking ones:
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I had a bet going with a boss in the 80's that our ultrasound Doppler units could have already been built very economically in WW-II and before, with tubes. He didn't believe it. When I gradually retire I could build such a machine. Got the tubes, sockets and stuff. Problem is, neither of us has cardiovascular issues so we don't really need it. Also, the only way to build such a device would be with highly polished wood and brass as an enclosure.
I don't think they've figured out how to make P-channel ones yet, though. ;)
When I was at IBM, I used an 811A to switch bias onto the grids of a drift chamber. No semiconductor could come near its performance for that job.
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics
160 North State Road #203
Briarcliff Manor NY 10510
hobbs at electrooptical dot net
http://electrooptical.net
Perhaps we should compile a list of classic endangered discretes between us so we can stock up on 'em while we can. Not that it'll do the designers much good, but repairers and whatnot could benefit.
Yes, the Russians make some killer tubes, god bless 'em and good luck to them for their efforts. Not sure about Chinese ones, though. I still don't trust anything made in China.
Some electronics from China are of good quality. Some of the dealers there are less than honest though. I just had one who promised twice to send a warranty replacement, never did, and doesn't respond to emails. I'll have to check how long one can place a credit card payment in dispute, just out of principle.
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