How to fabricate TO-3P transistors to fit into TO-3 sockets.
Here I have the 2 gold pins, a ring terminal, insulating bush, M3 washer, TO-3P Mica washer, Transistor, M3 16mm, & M3 20mm Stainless Steel screws.
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Cut the E & B legs off the transistor (as shown) and shorten the C leg, use a small file to lightly round off the square ends of the E & B legs - for neatness when soldering.
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Two gold pins shown, (left=uncut, right=cut) Cut the solder buckets off the gold pins, use flush cutters (as shown) just leaving the insertion stop disk at the top of the pin. Use a small file to lightly smooth the top of the pin where it was cut.
NB: Use safety glasses when cutting the pins, as the cut end of the gold pins really fly off when cut and could injure you.
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Here is the cleaned heatsink, the sockets (underneath) have been removed, cleaned and then put back.
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Insert the two gold pins into one of the sockets and tin the ends (as shown), the pins should be inserted just enough to grip in the socket. Cut a ~3mm strip off the bottom of the TO-3P mica washer so it doesn't interfere with the E & B legs, and position it as shown.
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Position the transistor, insert the 20mm screw with washer, then tighten down the screw carefully making sure to keep the gold pins directly underneath the E & B tabs. When the screw is tight make sure the transistor and mica washer are positioned correctly, and also the gold pins - then solder the E & B tabs to the gold pins - leave a little blob of solder on the top of each tab to show that the new gold pin leg has been soldered and for neatness.
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Now add the bush, and the ring terminal, slide the terminal onto the C leg and trim the leg as needed. Insert the M3 16mm screw, and tighten it up. Then solder the C leg to the terminal after making sure everything is lined up neatly.
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This is one transistor complete, note that I have not added any heatsink compound yet as I think it advisable to complete all this work without getting the compound everywhere. I will complete all 4 transistors on this heatsink before removing them all and applying compound to complete the job.
Part numbers:-
Gold pins = TE Connectivity 1650155-1, Farnell P/No 2310222
Ring terminal = Molex 0.5-1.0mm M2.5, Farnell P/No 2295580 (I drilled it out to M3
)
TO-3P insulating set (x10) = Multicomp MK3305, Farnell P/No 520238
I hope this is helpful.