Identify these transistors

In the 1960s the pocket radios hit the market and were sold everywhere. I have not opened one of them in years, but I recall the transistors used in them did not look like more modern types. They had a small metal can. Just a straight sided metal can, shaped like modern capacitors, but bare metal. Some had colored dots on them to identify the leads too.

First, I am thinking that they were geranium types. Is that correct?

Second, I have a very old GE transistor manual (edition 2) (PDF). No where in there does it mention the case style of them. What is the case style?

Seems those type of transistors came and went quickly. I assume they were the first generation of transistors.

Shortly after, I recall seeing a lot of metal cases that were shaped more like a hat, with a brim. Those too vanished. And I recall seeing some of the hat shaped types with a point sticking out of the top. I always wondered what that point was for???

Reply to
tubeguy
Loading thread data ...

Sounds like BC108 series the tab idenified the emitter I think.

Reply to
Allan

germanium yes.

There was TO1, but there were others

no, just the 1st generation cheap enough to go into pocket radios

More than one case type, eg TO39

to kill your opponents of course.

NT

Reply to
tabbypurr

I would say it is ACxxx or AFxxx ; they were cased in metal can and sealed with glass. The coloured point was indicating the collector. OCxx were cased in black glass with golden leads. The so called point (white, red, green or yellow) on top was indicating the gain range like, A, B, C today. The second one on bottom was indicating the collector.

All were Germanium transistors (take care, ||Vbe||=0.3V). Then came the 2N4xx.

Reply to
Look165

. .

** Yep - made by the Japanese and many others.

formatting link

** TO1

formatting link

** You are always missing the point .....

See here for pics of a great many old semis.

formatting link

.... Phil

Reply to
Phil Allison

Thanks for the link, Phil. What- no CK722!

Reply to
Wond

Like this? It has straight sides:

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
 Click to see the full signature
Reply to
Jeff Liebermann

If it was like this the 'point' was where the vacuum pump was applied, and the metal case pinched shut.

There was no good coating for Ge transistors to keep the surfaces clean, because Ge doesn't have a strong, stable oxide; paint was too dirty, and sputtering quartz was expensive. So, seal it in a vacuum was one solution. There were others (one gizmo I cut open had a kind of goo/gel blobbed over the germanium part).

TO-18 and TO-5 and TO-39 cases might have been e-beam welded at the top/base seam, which could also hold a vacuum.

Reply to
whit3rd

Germanium, son. Geraniums are the perennials your wife grows in the garden.

Reply to
bitrex

Check this page

formatting link

Reply to
KenW

snipped-for-privacy@myshop.com wrote: : In the 1960s the pocket radios hit the market and were sold everywhere. : I have not opened one of them in years, but I recall the transistors : used in them did not look like more modern types. They had a small metal : can. Just a straight sided metal can, shaped like modern capacitors, but : bare metal. Some had colored dots on them to identify the leads too.

: First, I am thinking that they were geranium types. Is that correct?

: Second, I have a very old GE transistor manual (edition 2) (PDF). No : where in there does it mention the case style of them. What is the case : style?

: Seems those type of transistors came and went quickly. I assume they : were the first generation of transistors.

: Shortly after, I recall seeing a lot of metal cases that were shaped : more like a hat, with a brim. Those too vanished. And I recall seeing : some of the hat shaped types with a point sticking out of the top. I : always wondered what that point was for???

Here

formatting link
are some photos of a few old, unusual transistors from my collection, including a red spot one. Are any of these the types you were thinking off?

Regards Tom Crane

Ps. The email address in the header is just a spam-trap.

--
Tom Crane, Dept. Physics, Royal Holloway, University of London, Egham Hill, 
Egham, Surrey, TW20 0EX, England.  
 Click to see the full signature
Reply to
<Use-Author-Supplied-Address-Header

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.