[EricS]

Hi guys, sorry for the silence - I've been traveling since last week. I purchased a NOS 84 tube and it measures properly with my meter - filament is good and all other pin combinations are open.

After inserting the tube and connecting the speaker, the measurement you asked me to make from Pin 4 of the rectifier to chassis ground measures completely open instead of the 200 ohms you specified. All four wires on the speaker harness are unbroken and show good continuity. The speaker coil measures about 5 ohms and the field coil measures about 1000 ohms.

With the 84 tube pulled, there is no connection (infinite resistance) from pin 4 to ground. The same is true from the pos terminal of the second cap to ground.

Any ideas on what to check next? I'm starting to think that a tube tester would be a good idea...

Eric