[rfeenstra]

Found the cause of the hum.  It's a ground loop through the house wiring.  The reason I didn't hear it before is that it was plugged into a different circuit.  The hum is gone if I plug it into that same outlet.  Neutral to ground on the "hum" outlet is about .5 volt AC, enough to cause the hum.  Looking at the schematic, the chassis is tied to the ground lug, while the neutral is the negative line.  The two are tied together at the electrical box generating a nice ground loop.  Part of what tipped me off is the fact that I noticed the hum increased ever so slightly when I turned on my Scott 16A, which was on the same circuit.  Finished an alignment so all of the bands are almost perfectly on.  It tracts very well except it is off slightly at the extreme ends of the dial.  The speaker is in getting re-coned as it was warped and distorting.  I changed a couple of dry electrolytic's that are in bathtubs and the line caps with safety caps.  They were also in a bathtub.  I'm going to leave everything else for a year or so, then revisit the voltages and see if the resistors drift any farther out of tolerance.  A few are a bit more than 20% high. I'm hoping all of the coupling caps, which are high value mica's, will hold up. The bypass caps are all oil bath type paper and seem to be ok. We'll see!