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PostPosted: Thu Mar 11, 2010 10:35 pm 
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I found this item on ebay:

http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... K:MEWAX:IT

It's supposed to be a transistor kit of some sort. What interests me are the little 3 wired components pictured. They look like very early transistors to me, unless I'm wrong....

Image

They could also some other components, I'm just not sure by looking at the pictures.

Norman
KA1GUK


Last edited by Norm_N_Tam on Tue Mar 16, 2010 12:43 am, edited 5 times in total.

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PostPosted: Thu Mar 11, 2010 10:38 pm 
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They might be ceramic filters. Used for 455 KHz or 10.7 Mhz. IF in compact radios.

Rich

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PostPosted: Thu Mar 11, 2010 10:46 pm 
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XtalHWJ wrote:
They might be ceramic filters. Used for 455 KHz or 10.7 Mhz. IF in compact radios.

Rich


Rich,

You could be right at that. There are 8 of them that I can see. I wonder why so many.

Norman
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PostPosted: Fri Mar 12, 2010 12:27 am 
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Those are Russian silicon transistors, from the 70's or 80's I believe.


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PostPosted: Fri Mar 12, 2010 12:42 am 
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http://cgi.ebay.com/KT315G-Vintage-Russ ... 1e5ad48305


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PostPosted: Fri Mar 12, 2010 12:59 am 
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Rune wrote:
Those are Russian silicon transistors, from the 70's or 80's I believe.


It's amazing that anyone made transistors that looked like that in the 70's or 80's. They look like some of the very early (about 1950 or so) prototype transistors I have seen in pictures.

Image

Image

Most of the early ones were germanium, although some early silicon transistors were made for research purposes.

Norman
KA1GUK


Last edited by Norm_N_Tam on Fri Mar 12, 2010 8:50 pm, edited 2 times in total.

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PostPosted: Fri Mar 12, 2010 1:16 am 
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Around 1980, I was with Westinghouse and we had a contract to construct a semiconductor manufacturing plant in Poland.

The Polish wanted to establish some trade with us and proposed to sell us some 15 amp SCRs made with Russian technology.

I got samples and cut one open to see the construction. Instead of an ultrasonic wire bond to the gate area of the chip, there was a hand-soldered wire. Instead of using glass or silicone resin to coat the edge of the chip, they simply added mineral oil to the case before welding the cover on.

Amazingly different!

Rich

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PostPosted: Fri Mar 12, 2010 3:06 am 
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XtalHWJ wrote:
I got samples and cut one open to see the construction. Instead of an ultrasonic wire bond to the gate area of the chip, there was a hand-soldered wire. Instead of using glass or silicone resin to coat the edge of the chip, they simply added mineral oil to the case before welding the cover on.

Amazingly different!

Rich


It sounds to me that not only do they look like early prototypes, they are constructed like them too!

Norman
KA1GUK


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PostPosted: Fri Mar 12, 2010 12:38 pm 
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Norm_N_Tam wrote:
It's amazing that anyone made transistors that looked like that in the 70's or 80's. They look like some of the very early (about 1950 or so) prototype transistors I have seen in pictures.

Us Europeans were not ''better'' if it can be said that way, with the Sot-25 transistor packages used by Mullard, Phillips and so on. To me it looks like the Sot-25 is even more bulkier than the Russian/Soviet one. But, they sat very sturdy on a PCB.

Image


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PostPosted: Thu Mar 18, 2010 7:59 am 
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Rune wrote:
Us Europeans were not ''better'' if it can be said that way, with the Sot-25 transistor packages used by Mullard, Phillips and so on. To me it looks like the Sot-25 is even more bulkier than the Russian/Soviet one. But, they sat very sturdy on a PCB.

Image


I found an interesting little computer interface circuit for a BC148:

Image

It seems that you can sub a 2N2222 for those little guys! But you are correct, the shape of the legs on that particular package were meant to provide a strong connection on a PCB.

Norman
KA1GUK


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