[RodB]

The freq counter is connected to pin 6 of the 12SA7 (cathode). The antenna measures 1.3 ohms. The resistance of pin 8 to B- is 3.2 meg and the voltage was -1.3v to -4.0v depending on the tuning of the gang cap. That second harmonic occurred to me too because it might be closer to 750 kHz which is half of the 1500 I tuned to. I can't get an accurate location of the tuned station because the dial face is still in the cabinet. I'm glad you think its not the coil!

I'm going to check out the area around the tube socket and maybe the osc section of the gang cap. The circuit is pretty simple, not many components.