oldest semiconductors still in use

I bored and wondering what some of the oldest still in production semiconductors there are out there.

let's ignore the weird companies that repackage die from out of business companies and stuff like that.

z80 processors are still being made, but there's got to be some series of diodes or transistors that are much much older.

Google for numbers like 2N404, or CK722. Maybe other old farts remember some other numbers.

Good Luck! Rich

The 555 is still made.

...

tm

You can still get new 1N34As, and NTE still makes selenium rectifiers--I don't know if they took over somebody's old process, but probably so...I can't imagine doing it from scratch today!

Cheers

Phil Hobbs

The 555 is ca. 1970. uA/LM741 is a couple years older, but for integrated circuits, maybe the SN7400.. still 1K+ in stock at Digikey.. around '64? That's 47 years!

Just going by low-numbered 1N and 2N parts:

Germanium: 1N34A's are still available. NTE has a bunch but I bet they are new old stock... maybe start the line back up when they're gone. I see 1N270's still sold by Central Semiconductor.

Silicon: 2N708 and 2N918 seem to be actively manufactured.

But older than semiconductors: 2A3's, 6L6's/derivatives, 6SN7's/Soviet equivs are being made still and at least in the case of the 6L6, I betcha some of the Russian/Eastern Block countries never decommisioned/ recommisioned the production line. I'm pretty sure the 2A3's are a new production line.

Tim.

"Cydrome Leader"

First sold back in 1971, around 1 billion units per year are still used.

.... Phil

CKE still makes selenium surge supressors as I recall. They're big finned things, like selenium or copper oxide rectifiers. I have no idea what they're for. Dean Technoloy still drags weird stuff like that to trade shows.

Does anbody have any idea why somebody might decide they need a 1N34 or something like that these days?

digikey does seem to have real and plain 7400s (plural, not S version) in stock.

Last question- would anybody know if the specs for this have drifted over the decades? If I blobbed some epoxy over a 1970s 7400 and a new one would anybody be able to tell them apart at all?

I seem to have lost my CK722 (several bucks new - back when a dollar was worth something). I still have a couple of in the box 2n404s.

On a sunny day (Wed, 05 Jan 2011 17:18:06 -0600) it happened Dennis wrote in :

In my box now: OC140, OC 76, OC460 All Ge transistors.

OC460, 1959:

OC 76, 1955:

The OC140 is a glass tube painted black, if you scratch of the paint it becomes a photo transistor, 1959:

An other interesting old part: FHZ55/500, 500V Neon ? tube parallel stabiliser.

I was looking earlier to see if anyone still made germanium transistors. The low Vbe wold come in handy occasionaly.

All I came across in stock with Farnell was the OA47 diode.

How about cpu's?

Cheers

George H.

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xt -

I remeber finding some in a diesel /(electric) train wreck when I was much younger.

George H.

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es

Well educationally they are interesting. There's a whole crystal radio community, that detects with tuned LC's and Ge diodes.

George H.

To replace one that was designed into older equipment that still works?

Thanks, Rich

The 2N2222 is fairly old, or the 1N34..

Fry them for the "good" smell; gets adsorbed into the skin and then you stink like a skunk every time you sweat.. Makes for quite a difference in social acceptability..