Re: Reforming Capacitors: EAI Analog Computer TR-48
- --- In email@example.com, Matt Patoray <mspatoray@...> wrote:
>I've seen pictures where some guys have opened the can, replaced the guts with new caps and resealed it to look original. This will be our last resort, the owner of this computer prefers to keep things as original as possible.
> If they are the multi section cans, if there is room underneath what u can do is just solder new ones below the circuits on a terminal strip, get as close as you can with the capacitance, higher is ok but not too much over. As for voltage go at least 50% higher. If you go that route and use radial caps get 105 degree C ones.
> This can be treated more like an old radio or tv instead of a computer.
>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.