What is this component?

[misterc57]

Anyone know what this 8 pin TO-5 package component is? I have not been able to find anything online.

F2500 728 7822C

Thank you, MC

[Jon Snell]

You may find it is a relay. According to my Comway spares catalogue from 1980 the F2500 could be a DPDT 50mA relay. Unfortunately part of the page is missing but it is in the signal relay section.
Obsolete for many years.

[Enzo]

Where is it? What make and model thing is it used in? Today we expect op amps to be little black square things with four legs down each side, but back when, they indeed came in round metal packages as you describe. It could easily be an op amp. That is a 1978 date code.

[mhuss]

Just by appearance, it could be a (really old) op-amp. Some resistance measurements could quickly confirm or deny the relay suggestion.

[misterc57]

Where is it? What make and model thing is it used in? Today we expect op amps to be little black square things with four legs down each side, but back when, they indeed came in round metal packages as you describe. It could easily be an op amp. That is a 1978 date code.

Did not come out of anything. It is NOS and part of a whole bunch of components lot (used and new) I picked up.

[misterc57]

Just by appearance, it could be a (really old) op-amp. Some resistance measurements could quickly confirm or deny the relay suggestion.

Which pins do I need to measure?

[mhuss]

Just start at one pin (the tabbed one is a good place to start) and measure resistance between that and every other pin, Move one left and repeat, Continue until you get back to where you started. A relay will have low resistance in both directions across the coil and close to zero resistance in both directions across closed contacts (up to two sets for a double pole relay). Everything else will read 'open.' You will not see this set of readings with an op amp.

[mozz]

I'm guessing opamp as i see them daily like this. There are also relays but not as common.

[Enzo]

The 8-leg part has the same pin connections as th common black plastic ones. The little thingie sticking out serves the same purpose as the notch in the end of a plastic DIP IC. You count legs from it. Today we mostly see dual op amps, but back then single op amps - like a 741 - were more common, so note the pinout is different between single and dual.

[loudthud]

I worked at a place that used relays similar to this. They were $10 each back in the 80's. Look for two opposite pins to have the coil, about 50 Ohms, and as you move around the circle two adjacent pins will look like a short (two places), the rest will be open.

Schematic something like the pic below.

[Enzo]

There you go, two reasonable alternative IDs, can't think of anything else it might be?

[Mick Bailey]

Some matched transistors such as the AS394H were supplied in TO5-8 case.

[g1]

I suppose it could be some other kind of IC as well?
I also have some dual Fet's and dual transistors in cans like this, but they are 6 legged type.

[Helmholtz]

I suppose it could be some other kind of IC as well?

Sure, apart from most early opamps (709, 741 etc.), also OTAs (3080), voltage regulators (723) and many application specific ICs came in that package.
Sealed metal cans were considered to have lower failure rates than (early) plastic packages.

[Mick Bailey]

Here's the pinout of a dual transistor package with 8 pins.