Hi Ed., The converter might be weak and able to operate (poorly) at the broadcast band but not at higher frequencies. Probably the oscillator is stopping. The converter tube is a good possibility and you can try another if you have one. You should be able to measure a few volts negative at the oscillator grid if it's oscillating. It could also be low voltage supplied to the converter, perhaps due to high value resistors. You can try swapping the XXL tubes if you don't have a spare and see if that makes the oscillator work at shortwave frequencies. A DC voltage check might pinpoint the faulty section. I'll email the schematic. Good Luck, Don Black.
: I have been restoring a Philco 42-340 radio and have the AM band working. However, I can not seem to get the short wave to work. I have checked the antenna and switch contacts without success. Is there something I am overlooking? The AM reception is limited (if this is any clue to the sympton).
: Any info to where I should check would be appreciated!
: Ed