Re: [midatlanticretro] Reforming Capacitors: EAI Analog Computer TR-48
- On Thu, Oct 11, 2012 at 03:28:37PM -0000, joshbensadon wrote:
> Does anyone have any experience or remarks to make about these CANMine were mid 60's. Are these aluminum electroltytics or one of the older
> capacitors from the late 50's or early 60's?
technologies? You will find people have widely varying options on what
to do with them. What I did:
>Yes, In my opinion you are correct.
> Here's a transistor with 430 on it. Would that make it 1964, week 30?
> Transistor part number is 2N1218. Or does the 430 refer to the factory the
> transistor was made? or other?
> Photo of transistor posted in the photos/Josh Bensadon folder of this group.
> I've seen some IC's with only a 3 digit code on them (not part of this analog
> computer). Case in point is the following:
> RCA H 650
> Is that to mean 1976 week 50?
> H being the factory where it was made?
In the early years of semiconductors most parts have three digit date codes.
You have to know the approximate decade the part was first produced to get the
Sometimes you have trouble telling the part number apart from the date code.
In the 1970s a lot of the 7400 series ic's had date codes like 7414 and a part
number like 7404.
I was always having trouble with those.
A good history of early transitor marking can be found here.