[Ron Ramirez]

There is no local oscillator in this set. It's a TRF, not a superheterodyne.

I have no idea when it was made, but it seems to be nicer than a lot of TRF sets of the late twenties/very early thirties...three stages of RF amplification, and push-pull 45 outputs.

I don't see much in the way of components between RF stages. RF coils, the 0.25 uF cathode bypass cap that is common to all of the RF amplifier tubes, resistors in the front end and voltage divider network, tubes...any of these could be causing the problem. Also a bad field coil, or filter choke. Check the voltages. You are lucky in that Rider's gives the voltages. A lot of the schematics for smaller companies such as Jackson-Bell didn't even give component values, let alone socket voltages.