[Hallicrafters] Reviving nice SX 100

[John King]

I recapped my SX 100 and it is working as best I can tell with questionable band performance due to propagation.
First thing I noticed was a non operative BFO. To make sure the problem is not the tube, I removed the 6SC7 tube (audio amplifier and BFO) tube from my SX 96 and substituted it for the one in the SX 100. The BFO still did not work. I am waiting for manuals to arrive, but I suspect a component in the BFO circuit. Hopefully it is not an open BFO coil. Some BFO circiuits have a csapacitor or two in the BFO can which are hidden from a general re-capping. The SX 100 had one original  Hallicrafters brand tube after 50+ years.

The BFO is my greatest current proble, Without the BFO, I cannot detect whether the BFO is working or not.
The AVC works well and the S meter works also. Needs mechanical adjustment for calibration purposes.
The noise limiter appears to be working some as when turned on, changes occur in the audio of the signal. 
Next, I will attack my very nice Hallicrafters, SX 96 and give it the same treatment. And then my nice S 53 receiver.
I really  love to hear them when the old receivers give the cry of re-birth.
73, John, K5PGW