old SCR/Thyristor identification

[rav]

Greetings,

I've come across a box of something that looks like the Microsemi GB301A SCR (http://www.microsemi.com/existing-parts/parts/41622). However, instead of 3-pins, these have 4. Some of these are marked AX, AQ, or BB (others have no marking). All are gold plated, and all are engraved with a `D` on one of the hexagonal edges. There are no model numbers or other forms of identification. I'm interesting in knowing what I've got here, and any help would be appreciated. Two pictures are attached.

Thanks,

RAV

 

[shrtrnd]

I can't see the pictures very clearly, but they're probably thyristors,with the hook terminal (the 4th lead), being an isolated case-ground.
The AX, AQ, BB were probably just markings for assembly by techs at the place where the devices were installed in some proprietary equipment. You won't be able to ID them with what you can see. You'd have
to test them in a circuit to get the operating characteristics and parameters.