Greg Mayman wrote in a message to Roy J. Tellason:

 -=> Roy J. Tellason said to Greg Mayman
 -=> about "*BIG* TRANSISTORS" on 12-18-03  04:06.....

 GM> Yep. For my money they are SCRs.

 RJT> I don't think so,  but let's see what an ohmmeter has to say about
 RJT> it... 
 RJT> Nope.  Reads like an NPN transistor,  with the pin that's common to
 RJT> the case being the collector,  I'm guessing.

 GM> It's time to set up for some DC tests with a power supply and
 GM> resistors, and see if they act like NPN transistors.

Don't need a power supply and resistors -- testing with an ohmmeter is quite enough.

 RJT> They're pretty dirty,  I need to figure out something I can clean them
 RJT> with that won't affect any numbers that might be on them.

 GM> Plain water and a soft brush is the safest, but there are no
 GM> guarantees that even that won't remove the numbers.

Yep.

Looking at what I can see for transistors in that sort of package in the
ECG book,  their replacements seem to be rated at either 20A or 50A for Ic
max.

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