[OZ4]

I just spent two and a half days trying to get an oscillator running in a 71-123 with the 36 tube. It seems that most Philcos of this age use the same 36 tube oscillator. So after doing the continuity check on the coil windings it too needed rewinding both the primary and the secondary. After completing said tasks the osc ran at about 4.5 mhz. I measured it with voltmeter that has a counter in it. I also could see lots of harmonics and ringing while tuning across the band with a scope clipped over the plate wire of the 36 tube not a direct connection just hanging on the insulation. It was really unstable. I spent two days trying to find what was bad. first I thought I had wound the coil wrong. So I checked it against the coil of an 89 radio coil that works and after much checking and more checking all the caps and resistors I came up with the thought that the inner coil must be bad even though it checked good. Then just before I was about to rewind the inner coil a thought came to me. What about the coupling between the inner and outer coils. I took my signal generator at 1.2 mhz and hook it up the primary winding and measured the output of the inner coil while moving it in and out of the outer. There was a huge difference. The peak was not at the normal location it was about 3/4 of and inch out from the bottom of the outer coil. Now this did not mean that this was the fix but after I reinstalled the coil assembly with the inner loose and a short jumper wire where the two lugs are normally soldered together so I could move the inner coil in and out while watching the scope. And there is was!!!!!!! after days the oscillator was clean and stable through the tuning range with the inner coil hanging out about 5/8 inch of the bottom of the inner. See attached image. You can see the tip of the lug from the outer coil hiding behind the dogbone resistor and the lug from the inner coil just to the right of the dogbone wire.
Hope this helps someone.