[MrFixr55]

Hmmmm,

Roy, I still think that there is a big problem in the area of that IF transformer. The plate voltage of that 6F7 is much lower than it should be. The voltage drop across the primary of the 2nd IF transformer should be minimal, as the resistance of the primary coil is only 11 ohms.

Consider that the specified voltage drop across the output transformer is only 10V for a tube (6F6) that likely draws about 30 mA over a 250 Ohm resistance of the output transformer. Consider that the specified voltage drop for the IF 6K7 is nil (250V vs the B+ output of 250V), the average plate current of a 6K7 is only about 5 mA and the resistance of the 2nd IF primary is 11 Ohms. Your measured voltage is only half the specified voltage. Either something is horribly wrong with the transformer or there is a bad solder connection to it or within it. I believe that you previously stated that the resistance of the transformer was good. However, remember that the current across the circuit when measuring resistance is in the order of microamps when using a DVM. In real life, the voltage drop between the B+ supplying the transformer and the plate of the tube is much more that should be occurring at 5 mA at 11 Ohms.

As to the general fluctuation in B+ after the field coil as opposed to before the field coil may indicate a problem with Cap #60. However, also consider the resistance between the negative lead of the Cap #60 (chassis ground) and the negative lead of Cap #62 (the power transformer HV secondary). As current changes, voltage changes.

Bottom line is that Job #1 is to determine why for a 5 mA load the drop over 11 Ohms is 125 V. This is a violation of Ohm's law. There has to be a bad connection or something else going extremely wrong there, and likely causing the noise you hear.

I think that you are close to solving this issue.