[fenbach]

hi keefer,
compare the hum using the original and the AAR and the aurora vibrators to see if the tone of the hum varies slightly. and if you're using a 120 volt power supply, see if the hum is the same using a battery. hearing different tones is a clue. i'm not sure yet if i will have a clue.

[Keefer]

Lol.I am using my  automobiles battery and the hum isn't real bad.I am going to check my b+ and see my voltages.Will let you know what I find.

[Keefer]

        Happy Thanksgiving all you guys.Fenbach finally checked voltages and no pins go over 140.I will include pic of 84 tube and cap.

[fenbach]

keefer,
i tested the plate voltages on a [working] F-1442 philco out of a '37 ford. it has nearly the same tube sequence. these are the voltages i got.
both 78s - 190V
6A7 -200V
75 - 152V
41 - 184V
test the voltage where the two 64 caps meet. which are connected to the cathode, pin 4, of the 84 tube. that definitely should be 200V or more. regardless, try pulling one tube at a time and retesting the voltage where the caps join. could be that one of the tubes is pulling too much current.
if you don't get 200+volts DC where the caps join, maybe half the power transformer is open. check the AC voltage at pins 2 and 3 of the 84 tube. which are the output of the transformer. they should both definitely be north of 200V AC.

or maybe just one side of the vibrator is working. test the DC voltage at both small pins of the vibrator. which are input to the transformer. you should get about 6V DC. if half the vibrator is bad [or has a bad connection], you won't have any DC voltage on one of the small pins.

or maybe one side of the 84 tube is defective. try subbing in another 84. or testing the one you have.

big haystack, few needles.