Poor sensitivity on Stromberg Carlson 561

[Len]

Have recapped, out of tolerance resistors changed, tubes tested, realigned, all coils test good. Only pulls in strong stations, but not clear. Voltages good on rectifier and output tubes, some voltages not correct on other tubes. If I touch the wave trap coil the radio wakes up but still sounds bad. I believe some of the voltages on the schematic are incorrect.

Any thoughts?

Thanks, Len

Attachments:

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   strom-561-scaled.jpg
   

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   Strom-tube-volts.pdf
   

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   Strom-schem-voltages.pdf
   

[John Greenland]

Merry Christmas Len,

I have 2 suggestions. ( please keep in mind that this comes from a tech whose is as far away from an expert as we are from the sun )

1: Do a substitution ( if you have spare tubes ) on the tubes which have incorrect voltages. Sometimes a tube tester will not be 100 % right about the tube.

2: get a small brush like the ones used by welders to clean the nozzle on a welding torch ( Canadian Tire has them) and clean the socket pins especially the sockets where voltages are wrong

Good luck
John G. VO1 CAT

[Len]

Thanks John, I finally found the problem. Someone had installed a wire on the antenna coil thus shorting out the signal. Should have seen this sooner but was looking too deep into the problem. Cut that red wire and the radio woke right up picking up stations all across the dial loud and clear.

Attachments:

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   Stromberg-antena-scaled.jpg
   

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