fixing IF caps

[DaveWM]

thought some may find this interesting.

http://www.youtube.com/watch?v=WrjAk...CVtyRrqXVtll-g

[radiotvnut]

In today's world, I'm finding more and more receivers from the '50's and '60's that have bad IF transformers. Obviously, the repair procedure is a little tedious; but, since good IF's are hard to find, it's often the only way to save one of these sets.

[Einar72]

It's also good to see if a bad bypass cap or tube was the cause before reinstalling...

[DaveWM]

I checked the parts around it, the problem would present with a very light pressure applied to the transformer lug. Thinking the movement at the lug may have been transmitted along to another part (in this case only parts directly attached to the lug was a resistor and a a cap) I carefully prodded at them while measuring them (power off) for resistance and capacity with a analog meter and a eye tube (modern DMM not good for this kind of work as they are too slow to react). those parts did not seem to have any shock sensitive issue so I deduced it had to be either a broken wire that was intermittent at the coil or a inside cap that was making poor contact and changing value. Either way it would require removal for inspection. I checked the wire for continuity by the analog meter and prodding, leaving the most likely suspect being the cap. replacement of the cap albeit the incorrect value for now resolved the intermittent nature. I am hopeful that a 33pf will be a better match and give a better Q from the transformer.