2sc1589 and S10-12 vintage BJT packages?
They are used in a vintage (80s) Yaesu FT-301S HF transceiver, in it's power amplifier (10W output only).
The circuit of the amplifier is on page 22 and the components on page 44 of the PDF.
I am trying to find out if the packages of these transistors are ceramic (which can be more easily broken and expose any possible BeO) or plastic.
Transistor packages will hardly break by itself. Do you plan to disassemble the power stage?
SC1589 clearly shows up as plastic package in datasheets on the internet. No idea about less common S10-12.
No I don't, I just worry because the TX is not working (of course there are lots of reasons for that) and one of the reasons might be a broken ceramic transistor, especially if the equipment has been dropped to the ground from a height at some point in the past (second hand). The case of the transceiver does not show that kind of damage...
Decades ago, I have broken a ceramic planar transistor on an FM transmitter by screwing it too much on the heatsink (it was one of these types with a single central screw to the heatsink) when already soldered to the PCB above. Didn't get BeO poisoning, but perhaps it's base was not destroyed, I don't remember now.
So I am a bit concerned about the transceiver, how to handle it when I service it etc.