What is this component?

[misterc57]

Is the tab pin 1 or pin 8? I have seen references to both. When looking at the bottom I am counting in a clock wise rotation?

Assuming the tab is pin 1 and counting in a clockwise rotation looking at the bottom. I have seen the following resistance.

Pin 1 has no connection to any other pin.

pin 5 to 6: 1654 ohms
pin 5 to 7: 4 M ohms
pin 5 to 8: 3.8 M ohms
pin 5 to 2: 1704 ohms

pin 5 to 1: OL
pin 5 to 3: OL
pin 5 to 4: OL

[Dave H]

The tab is pin 8 and yes it's counted clock wise looking at the bottom.

Edit:
It could be an op-amp. Correcting the pin numbers 4 to 5 is -ve supply to an offset pin and 4 to 1 is -ve supply to the other offset pin.
A 741 has 1k between -ve supply and its offset pins.

[misterc57]

The tab is pin 8 and yes it's counted clock wise looking at the bottom.

In that case the readings are

Pin 8 has no connection to any other pin.

pin 4 to 5: 1654 ohms
pin 4 to 6: 4 M ohms
pin 4 to 7: 3.8 M ohms
pin 4 to 1: 1704 ohms

pin 4 to 8: OL
pin 4 to 2: OL
pin 4 to 3: OL

[Dave H]

Thanks, I was doing the conversion in my head for the edit above and got it wrong. I've corrected it now.

[misterc57]

So possible an op-amp like below? Any other tests I can do?

[Helmholtz]

Don't forget that the DCR readings with a semiconductor device depend on meter current and polarity.
Maybe compare to a verified 741.

But I doubt it's a simple 741 and if it's not there may be a hundred other possibilities.
I wouldn't waste my time with this, even if I had many of them.

[eschertron]

A stash of OTAs might be valuable to some. But sleuthing what exactly you have there, even if you can focus in on the family of devices, will be quite time-consuming. Sometimes things like that sit in a bin for a few years until the puzzle pieces simply "drop into place".

[Enzo]

Whatever they are, they willl likely be obsolete and modern parts run rings around them. HOWEVER, by going through this exercise, you might learn something. learn some techniques, invent some procedures

[misterc57]

Yeah I have a lot of them and thought I would learn something in the process. At some point I would like to breadboard it and play around...

One clue I have is the lot originated from a ham radio guy

[Dave H]

If it's an op-amp I don't think it's a 741. I've just measured several old 741s and they all measure 1k from 4 to 1 and 4 to 5

You could try breadboarding this circuit - make a +/-9V supply with two 9V batteries. Connect pin 4 to -9V, pin 7 to +9V and pin 6 to pin 2. Connect a potentiometer between +9V and -9V and connect its wiper to pin 3. If the output voltage (pin 6) follows the voltage on the pot wiper it's an op-amp, if it smokes it's not.

[J M Fahey]

FWIW my first successful amplifiers used TO5-8 case 741:
We are talking 1969-71
I had to use those because I used Tube amp style eyeletted boards; I could fit these by spreading legs, not possible with DIP plastic ones.

[g1]

You could try breadboarding this circuit

You need one of these jigs. I've never even taken it out of the package. I'd think getting the pins lined up could be a pain at times.

[dmeek]

Can you cut the top off and see what's inside.

[nosaj]

You need one of these jigs. I've never even taken it out of the package. I'd think getting the pins lined up could be a pain at times.

I have some copper clad breakout boards for transistors like that.
nosaj

[Leo_Gnardo]

If the output voltage (pin 6) follows the voltage on the pot wiper it's an op-amp, if it smokes it's not.

Heh, heh....