I also found this on AMfone posted in 2015 by member Tim WA1HnyLR.
Your comments please DMOD.
I agree with most everything except for the first 12AX7A (V7A) stage. See my modifications in the dotted line, upper left, Schematic 1. My experimentation shows a 3.3 megaohm resistor on Pin 2 of V7A is of sufficient loading to get the low's needed. What he didn't take into consideration is that by going to a 10 megaohm grid resistor, you increase grid leak bias, so he should have changed R18 from 4.7k to some lower value to get the proper grid bias.
Tim's main contribution here (and a good one) was to move the T2 tertiary winding's feedback to a low impedance path, the cathode of V7B, Pin 8. His modification is shown in the lower right in broken line format, Schematic 1.
Tim wrote-up a number of mods for the Ranger, with one using a phase splitter and removing the T3 interstage transformer, but that is beside the point here.
The 1614 screen Voltage regulator is shown on Page 2, which meets the RCA specs for ClassAB1 modulators.