07-26-2023, 09:19 AM
Nice set Ed! Hose it off and disinfect really well. Chassis finish looks really good! Reminds me of my Crosley 5C2 but yours is much better built, especially having a transformer. I wonder why the 84 was not more popular with small radios. It would give sufficient power and save a filament winding. Interesting enough, I just looked at the schematic and they do, in fact, have a separate filament winding for the 84. Any of the Philco schematics using the 84 that I have looked at, including my 41-250, use the same winding for the 84 filament as the do for the other tubes. They can do so as the 84 cathode is insulated from the filaments. Per the RCA Receiving Tube Manual (RC12), the maximum potential difference between heater and cathode is 500V. The main issue in using an 84 is that the tube delivers a maximum of 50mA vs the 125mA of an 80, but for a set with a single output tube, it should be sufficient. (Heck, the 41-250 has P-P 41s, but at 180V, I am sure that the output is much lower than if driven by 250V.
"Do Justly, love Mercy and walk humbly with your God"- Micah 6:8
Best Regards,
MrFixr55