[Collins] Re: 75S3 Questions

[Bill Stewart]

Man, what a great response to my questions. Many thanks to all who 
responded.

I have shut the receiver down, except for some testing. In previously 
looking around the rcvr, I did note that there were only five of the paper, 
tubular capacitors...all Sangamo and I believe either .1 or .05's. They will 
be replaced. The coupling cap to the grid of the 6BF5 is a disc. I think 
disc caps usually hold up ok, but will check the 6BF5 grid bias.  Also, 
someone mentioned the bias rectifier being a S/T cube...that's what I have. 
I will replace it with a 1N4007, same as used for the B+ diodes. It does 
have 150vdc B+. I think the fuse-block diode mounting was orig with this 
rcvr since the mounting nuts have some loc-tite on them.

The B+ 'lytic in my rcvr is a Sprague with twist lock tabs, 183-1764-00 (may 
be a Collins in-house number). It is 40/40/40 uf @250vdc. It is about 1 inch 
in dia. The ones I found at Surplus Sales was 40/40/20 at 450vdc 1.5 in. dia 
and another was 40 at 350vdc and 40/40 at 300vdc 1 3/8 in. dia. I'm not sure 
if either of these would fit the chassis slots for the twist tabs. Anyone 
know for sure. I may try my hand at restuffing first.

I did receive the manual on cd today and its the forth edition, 1 jul 1963. 
It's not the exact manual for my rcvr but will do for a while. By the way, 
if anyone needs to copy this version of the manual, let me know and you can 
borrow my cd.

On the S-meter illumination, I noticed the inside of my S-meter is black. 
The inside of my 30L1 meter is white.

Guess that brings me up to date for now. I have some other questions re: hum 
and some squealing at close to max volume. These problems may go away after 
I re-cap so will hold off on these questions.

Again, many thanks for all the help...it IS a real nice rcvr...73 de Bill 
K4JYS