[Collins] 51S1 recuperation

[David Evans]

I am trying to recuperate a 51S1 I picked up at the flea market in a partly
damaged state. Have repaired the meter, had the  power transformer
rewound-it had been burnt out, and am now using my old heathkit signal
generator (from the flea market too) to track down problems.I have reception
of a sort on all bands and have peaked the if coils etc.Am getting
closer...I think now I'll replace the transistors - they are ancient of
course- any idea out there what the subs would be for 2N647 and 2N 637B?
73 to all David CT4RL