Interesting Diode AA129
 

Was the AA129 made out of reject transistors ?

John.

Re: Interesting Diode AA129
 

Can't answer that, but interesting that a few suppliers (eg Cricklewood, Littlediode) still seem to have stock of them, so maybe not a popular item even in it's heyday.

Re: Interesting Diode AA129
 

The fact that they have a Pro-Electron coding despite the OC71 style glass encapsulation suggests they may have been a way of disposing of old stocks or sweating obsolescent production facilities once the AC/AF series of transistors were introduced.

Re: Interesting Diode AA129
 

You are possibly right Paul, it just looks a botched job.

John.

Re: Interesting Diode AA129
 

They do look like an OC71 or OC45 with the base tied to the collector.

Re: Interesting Diode AA129
 

Gives them a way to convert duds into a revenue stream. Only needs one out of two junctions to be useable.
And can be done to anything found dud right up to post packaging.

David

Re: Interesting Diode AA129
 

Re: Interesting Diode AA129
 

If you do a Google image search, different manufacturers have used different packages for this diode. Soldered, welded and plain two wire. Intended as a stabiliser diode.

Re: Interesting Diode AA129
 

Full data sheet:

Attachment 206659

Cheers

Re: Interesting Diode AA129
 

I seem to remember the temperature characteristic of a transistor would work better for this specific application so it might be intentional design and not a way to get rid of duds.

Re: Interesting Diode AA129
 

Would be interesting to separate the leadouts and test as a transistor to see the characteristics.

Re: Interesting Diode AA129
 

Newmarket never made diodes as such, but I have seen a welded lead transistor used in this way.

Re: Interesting Diode AA129
 

The more common version of this as I recall was the AC128 used on convergence panels of the Philips G8