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Identify these transistors
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tub...@myshop.com
Feb 20, 2019, 12:13:25 AM2/20/19
to
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???
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???
Allan
Feb 20, 2019, 3:34:14 AM2/20/19
to
tabb...@gmail.com
Feb 20, 2019, 3:42:09 AM2/20/19
to
> 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?
germanium yes.
> 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???
NT
Look165
Feb 20, 2019, 4:47:41 AM2/20/19
to
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.
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.
Phil Allison
Feb 20, 2019, 5:01:53 AM2/20/19
to
tub...@myshop.com wrote:
.
.
http://oldtube.com/2N408-RCA-used-1pc.jpg
> 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?
>
** TO1
>
> Shortly after, I recall seeing a lot of metal cases that were shaped
> more like a hat, with a brim. Those too vanished.
http://oldtube.com/2N508-ETCO-Au-2pcs.jpg
> 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???
** You are always missing the point .....
See here for pics of a great many old semis.
http://oldtube.com/Oldtube-semiconductors.htm
.... Phil
.
.
>
>
> 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?
>
** Yep - made by the Japanese and many others.
>
> 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?
>
http://oldtube.com/2N408-RCA-used-1pc.jpg
> 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?
>
>
> 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???
See here for pics of a great many old semis.
http://oldtube.com/Oldtube-semiconductors.htm
.... Phil
Wond
Feb 20, 2019, 10:32:34 AM2/20/19
to
>
> .... Phil
Jeff Liebermann
Feb 20, 2019, 12:18:32 PM2/20/19
to
On Tue, 19 Feb 2019 23:13:16 -0600, tub...@myshop.com wrote:
Like this? It has straight sides:
<https://62e528761d0685343e1c-f3d1b99a743ffa4142d9d7f1978d9686.ssl.cf2.rackcdn.com/files/93218/area14mp/image-20150827-378-u7k0in.jpg>
--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
Like this? It has straight sides:
<https://62e528761d0685343e1c-f3d1b99a743ffa4142d9d7f1978d9686.ssl.cf2.rackcdn.com/files/93218/area14mp/image-20150827-378-u7k0in.jpg>
--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
whit3rd
Feb 20, 2019, 3:16:31 PM2/20/19
to
On Tuesday, February 19, 2019 at 9:13:25 PM UTC-8, tub...@myshop.com wrote:
> In the 1960s ... I recall seeing a lot of metal cases that were shaped
<http://www.oddmix.com/semi/5a_western_el.html>
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.
> In the 1960s ... 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???
If it was like this
> some of the hat shaped types with a point sticking out of the top. I
> always wondered what that point was for???
<http://www.oddmix.com/semi/5a_western_el.html>
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.
bitrex
Feb 20, 2019, 5:08:37 PM2/20/19
to
On 02/20/2019 12:13 AM, tub...@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?
Germanium, son. Geraniums are the perennials your wife grows in the garden.
> 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?
Use-Author-Suppli...@127.1
Feb 24, 2019, 1:23:30 AM2/24/19
to
tub...@myshop.com wrote:
: In the 1960s the pocket radios hit the market and were sold everywhere.
Here https://www.mklab.rhul.ac.uk/~tom/temp6 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.
Email: T dot Crane at rhul dot ac dot uk
: In the 1960s the pocket radios hit the market and were sold everywhere.
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.
Email: T dot Crane at rhul dot ac dot uk
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