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oldest semiconductors still in use

A

amdx

Phil Hobbs said:
You can still get new 1N34As, and NTE still makes selenium rectifiers--

What is the advantage of a selenium rectifier, today?
MikeK
 
C

Cydrome Leader

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.
 
R

Rich Grise

Cydrome said:
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
 
S

Spehro Pefhany

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.

1N34A, perhaps (a Ge point-contact diode). It is still being made in
China, and it dates back to the 50s or even 40s according to this
page:

http://semiconductormuseum.com/MuseumLibrary/HistoryOfCrystalDiodesVolume1.pdf
 
S

Spehro Pefhany

1N21 and 1N23 still made. They were in every WW-II radar receiver.

The 555 is still made.

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!
 
P

Phil Allison

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



** The NE555 is an outstanding example of a long lived IC.

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



..... Phil
 
C

Cydrome Leader

amdx said:
What is the advantage of a selenium rectifier, today?
MikeK

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?
 
D

Dennis

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

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.
 
R

Raveninghorde

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

Good Luck!
Rich

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.
 
M

Martin Riddle

R

Rich Grise

amdx said:
What is the advantage of a selenium rectifier, today?

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

Thanks,
Rich
 
C

Cydrome Leader

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

George H.

interesting.

Are there any modern drop in replacements for stuff like you'd use in a
crystal radio?

Or, if I were to take apart a modern communications satellite, would I be
able to make the most simple AM receiver possible?
 
J

Jeff Layman

The pictured part appears to have been made by Newmarket in the UK, a
company that went out of business some decades ago.

Yep, I missed that. NVOS...
 

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