09-19-2024, 04:01 PM
Hi Brad,
I had no idea that the overheating was problematic in this radio. Do you know the part number of the transformer you plan to use? I was surprised to find that the stock transformer HV secondary was only good for 131ma and the one 6.4 V secondary was good for 5A. I did not check all the tubes filament draw, but 11 tubes must be running very close to 5A. Though the 1942 parts catalog shows the transformer is good for 14-15 tubes. The Thyratron has its own 2.5V 2.5A filament transformer. I will check the motor transformer as it sits very close to the power transformer and may have been affected by the overheating. In looking through the parts catalog, I did see one transformer, 34-7455 for 15-16 tubes, that might fit the bill. It has dual 6.3V and dual 5V filament windings and the HV winding will handle 180ma. Not sure what chassis this was used in.
The existing transformer used cloth covered wires, though stiff, they are not compromised. The chassis itself seems to have about 50% rubber and 50% cloth covered wiring. The worst rubber wiring is in the station lamps harness.
I will not be doing any further work until I'm able to source a power transformer. Which is kind of disappointing.
Thanks for the info.
Rich
I had no idea that the overheating was problematic in this radio. Do you know the part number of the transformer you plan to use? I was surprised to find that the stock transformer HV secondary was only good for 131ma and the one 6.4 V secondary was good for 5A. I did not check all the tubes filament draw, but 11 tubes must be running very close to 5A. Though the 1942 parts catalog shows the transformer is good for 14-15 tubes. The Thyratron has its own 2.5V 2.5A filament transformer. I will check the motor transformer as it sits very close to the power transformer and may have been affected by the overheating. In looking through the parts catalog, I did see one transformer, 34-7455 for 15-16 tubes, that might fit the bill. It has dual 6.3V and dual 5V filament windings and the HV winding will handle 180ma. Not sure what chassis this was used in.
The existing transformer used cloth covered wires, though stiff, they are not compromised. The chassis itself seems to have about 50% rubber and 50% cloth covered wiring. The worst rubber wiring is in the station lamps harness.
I will not be doing any further work until I'm able to source a power transformer. Which is kind of disappointing.
Thanks for the info.
Rich