found a 1960s Philco Portable TV today at the Antique Mall!

[jr_tech]

At this point, a copy of the schematic would be very helpful.... I believe that it can be found in Sams 650, folder #2.
If this set uses a circuit similar to "slender seventeeners" and predictas of the era, you will find a fairly large cap ( .15 to .22 uf or so) connected near the cathode circuit of the 6dr7/6de7 (pin 8) to the vertical hold pot.... I would consider replacing it first.

jr