[Charlie]

Not that tubes wouldn't cause the sound fade, but I believe it would be more likely a resistor or capacitor changing value as the chassis warms. Since you've gotten rid of all your paper/wax caps, I would do some resistance checks from the tube sockets using your info in the sams. Keep in mind, you would want to do these checks pretty quick after powering down the set since the issue seems to be heat related.

Let's say you find a resistance reading to be way off from what it should be on a certain tube socket... wait a few minutes and come back to check it again. If the same check comes back a second time as something closer to what it's supposed to be, there's a pretty good chance you've found the problem.

If you think the only thing changing for you is your sound going away, first check thru all the sound circuits for resistance readings... starting with the sound output stage and work backwards back to the sound IF.

It can be quite surprising just how many resistors you might find way out of spec. If a particular tube socket pin is supposed to show 500 ohms from that pin to ground (or back to the B+ source) and your getting 250k ohms, that means that a resistor or several in that particular path have changed value. YOu would then follow your schematic from that socket pin backwards and check the resistors in that path... likely to find that bad one... or more.

You must also keep in mind that some of these paths can have slightly varied readings because a certain control adjustment (such as contrast, vert hold, or any other pot) will have an affect on your reading as it may be part of the circuit you're checking.

If the sound problem was a tube, it could be anything from the speaker backwards.

Regarding the ghosts, bad tubes in the IF strip commonly cause this... gassy or shorted. My CM color set used to have some serious ghosting until I found one of the IF tubes to have a short. Getting an IF alignment could also correct your problem... but that's something best left to those who know how to do it and should only be done once you've tried everything else. You don't want to go in there turning things... would just make it worse.