Hi! I am having the same problem with likely the same instrument. Did you ever find the data sheet for the
108-020k 0046? What replacement did you end up going with?

Thanks!

Moderator edit: New thread created from this.

 

Now a question nobody asked: Is the transistor actually used as a DC voltage regulator, OR IS IT AN "Output Transistor in an amplifier circuit, where it has to switch at a high frequency??? That is quiet a big difference