[Collins] 75A-4 Recap

[Kenneth Lopez]

Howdy folks,

Well, I've just acquired another 75A-4, just after selling mine.   
These things seem to follow me home somehow!  I guess I'll have to  
keep this one...

Serial # just over 1000, nice physical shape, some functional problems.

First, where would one mount the blocking cap to take the B+ off the  
filters? It is noted as C 144 on a later schematic.  This A4 is early  
enough not to have it installed.  What type of cap should I use here,  
disc ceramic?

Next:  I've seen the list of the "7 deadly caps" and note also the  
need to replace the Black Beauties.  Which others should I change?

What is the preferred type of cap?  Sprague Orange Drops OK for the  
black beauties?

It is working, but has pops, hum, etc.  Probably need to replace the  
HV mutli-section can.  I see one at Antique Electronics.  Expensive,  
but the only ones I could find.

As I dig further I'll report nasty symptoms.

Lastly, I am open to suggestions and guidance to bring this rig back  
to spec.


Cheers,

Ken N6TZV