- S-1828 made by " SI " in 1974. Or so I understand.
Then a couple made by RCA :
- CVT.......... 418
- CXK ....... 3M
I think you got the RCA types wrong, because the '64595' appears in the same place and has the same number of places as, for example '40319' etc., which are IDENTIFIABLE RCA part numbers. That said, I have two '64115' devices from RCA (also TO-3), on which I came up empty not only from the internet, but every databook which I have in print or PDF. Nada, zero, nil, rien, gornischt. Oh yeah, one of those totally unspecific 'parts search' sites associates the number with RCA, but that could just mean than someone has tried before me.
No RCA or Harris discrete / power databook and no other semiconductor data or substitution tables list ANY 64xxx number which could beeven remotely connected to the components in question, be it mine or yours.
One information is available from unknown sources: I have a '63857' (RCA) in TO-66 size, which I have marked down as a thyristor(SCR) without further data. Hm. When I get near the big TO-3 box, I will subject all of the unclear ones to a test with the Atlas DCA-75pro. Let's see what the wondersome device says. Other conceivable types, which are frequently packaged in TO-3 are triacs, double diodes, IGBTs, and MOSFETs.
But we must keep in mind that we can't even rule out categories on which it is completely lost, as it could be a thermoswitch, or any other special thing.
Maybe it is a RCA test item, and all devices intended for dimensional/mechanical inspection are '64115' and those for hermeticity test are '64595'. In such a case, we will never find anything and there could be literally anything inside, including random devices or nothing.
![WTF? :wtf:](https://www.eevblog.com/forum/Smileys/default/wtf2.gif)
And I have something on the SDT9308, although not much..
And you seem to have gotten ahead of me again - I had the SFC2309 erroneously listed as a 9V regulator.
Well done, grenouille électronique!