Re: 468 with no -2450

Chuck Harris
 

40673...Lysdexia strikes again ;-)

Tin plating was very common.... unfortunately. In many cases,
the bright tin plating was also inside of the can, and created
the infamous tin whiskers, and rendered the device inert.

-Chuck Harris

'Michael A. Terrell' mike.terrell@... [TekScopes] wrote:

Most of what I saw were tin plated TO-5 or TO-3 cans, in PA amplifiers when I did industrial repairs.

The 40763 was a popular Dual Gate, N-channel RCA FET in that five digit line. I replaced dozens, if not hundreds of those in 'Linear' brand garage door openers for a friend's 'Overhead Door Company' dealership. I believe that they were in four lead, TO-1 cans. We bought them 25 or more at a time, because he had many thousands of the old openers still in service. They were about 16 cents each, but now they can go for $16 each, when some turn up.

-----Original Message-----
From: "David @DWH [TekScopes]" <TekScopes@...>
Sent: May 26, 2017 12:31 AM
To: TekScopes@...
Subject: Re: [TekScopes] 468 with no -2450

Somewhere I have the RCA transistor databook with those 5 digit
transistors.

The thing I always remember about them is that they used nickel plated
steel cases which tended to rust.

On Thu, 25 May 2017 23:36:34 -0400 (GMT-04:00), you wrote:

RCA used to used a five digit code for semiconductors that hadn't been assigned a JEDEC number. Their predecessor to the 2N3055 was a 100 V version that they called the 40411. It was part of a consecutive set from 40406-40411 for their first Quasi-Complementary 701W audio amplifier design which was shown in their semiconductor handbook, around 1970. There was no stated logic for the numbering, and it appeared to just be sequential. Once they were assigned a JEDEC number, the old numbering was removed from current literature, making it difficult to find any data.

-----Original Message-----
From: "Chuck Harris cfharris@... [TekScopes]" <TekScopes@...>
Sent: May 25, 2017 8:12 PM
To: TekScopes@...
Subject: Re: [TekScopes] 468 with no -2450

AFAIK there is no Q110.

There is a transistor identified as line -110 in the
parts blow up, which is Q1108, as it is also identified
on the schematic. It is listed as being a 151-0140-00,
and as a 36568, whatever that is....
Michael A. Terrell

Michael A. Terrell


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Posted by: "Michael A. Terrell" <mike.terrell@...>
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