On Thu, 14 Mar 2019 11:04:55 +0000, N_Cook wrote:

TO18 size of can but inerference fit? mounted in a brass mount with
lens, no type number seen.
Actively passing 60mA drops 1.3V and DVM-D test shows 1V one way, so
Is this a laser or just an LED? 60 mA sounds to me like it might be a
laser, and fairly powerful.

1979? Hmmm, probably NOT a laser at that date, and hitting such an old
LED with such current would be pretty hard on it, unless the pulses were
short and the duty cycle low.

Possibly heating the whole assembly might make the emitter slide out.
I doubt these would be interference fit, as that could easily damage the
emitter. Likely, a TO-18 package had a fairly wide dimensional tolerance.
So, I'm guessing they used some kind of glue to hold it in place.

Jon