okay radio guys need help philco model 111

radio plays fine for about 1/2 hour reception volume great then gets quiet.
somethings getting hot or shorting out somewhere. tubes are new, all resistors all the caps , replaced band switch.
no wires shorted. I can turn it off a few minutes then back on works about 1/2 hour again. could it be one of the mica caps ?
IF so where do i get them.

Any help would be appericated
THANKS DENVER

Ok take a look at the tube sockets.Make sure they get good contact when the sets warm.Could well be a mica cap.Feel around once it stops playing.Something may be overheating.A cold solder joint can be the cause too.Sprman : )

WILL DO THANKS . This set is kind hard to work on big console have to slide chassi out to check anything.
THANKS DENVER