[RGK20m3]

First, I do not think the AVC is working; I fed a 1000kc signal directly to the antenna terminals via a .1uf capacitor and monitored the bias voltage on both the 1st and 2nd IF grids- no change as I varied the signal from minimum to maximum. I measured +11.1v on the cathode of the 6J5 and -2.8v on the grid (which is about the same as I measured at the grids of the two IF tubes). I verified all the components on the grid and cathode circuits, so maybe a bad tube? Original Philco....
I measured the resistance across the shorting switches for the magnetic tuning; 0 ohms when off and about 1.4meg when on. I checked both to ground at about 855k (which seems to be about right for the various resistors in the circuit). I verified circuit is correct and individual component values to within 10% of specification. I then powered up and had 0 volts across the shorting switches when off, and only .008v when mag tuning on; this voltage did not change as I adjusted the 85B trimmer. I measured one side at +.018v and the other at +.010v. I rechecked for a signal across the plates of the 6H6 and have a good modulated signal of at least 10v. Sounds like a bad 6H6?
I also checked the oscillator control tube; +4.08v on the cathode(s), 215v on both plates, and zero on grids- at least that tube seems to be working, and shows band switch is ok.
Radio receives well. What are your thoughts? I appreciate the help and any advice you can give.