I picked up a cosmetically very nice HA-5 "in perfect working condition." Ahem..... Anyway, after replacing the completely open filter caps and a defective VR tube, and going through the usual cleaning and connection checks and so on, the thing sorta works, but the output from the 5 MHz variable oscillator wanders around a few dozen hertz. It also has more drift than I'd like, certainly OK for AM but not too good for CW. I powered this with external regulated power supplies, including regulating the heater supply, but the wandering continues. Rather than shot-gunning a bunch of parts replacements I figured there was undoubtedly someone who knows this product intimately and could give some guidance. I also have two different schematics for this, which one is the preferred version? One has the cathode of V1A directly grounded, the other has a 120 ohm cathode resistor, but there are other differences as well. Thanks in advance.