40s Philco 40-145 BUMMER!

[DavGoodlin]

I think that fusing on the tube plates would be the same, a 1/10 amp fuse.
If you measure the operating current on the 340 volt B+ supply, its about 70 mA.
In my profession, adding 20% and fusing at that value is standard design practice.

I just acquired another 1939 Zenith radio, chassis and speaker only, that has a 6X5 in it.
No testing yet, but the transfomer is physically smaller in comparison to a typical Philco.

[NoPegs]

I just had a brainstorm on the 6X5 issue, since I'm studying the schematic of my 20A1 chassis Admiral and it has the silly 6X5GT on the LV side...

Could I use the guts of a "brightener" (Or preferably the type designed to work-around H-K shorts without the whole voltage changing part.) to just float the heater supply to the tube? Alternative options are just find a small >600mA 6.3v transformer core and tuck it up underneath the lower chassis. (There's so much room that I feel like I could tuck an entire AA5 set in there too!)

For my 1941 Zenith chairside I'm probably going to go with the multiple fuses option, since that chassis is much more dense than the lower on the Admiral.

[DavGoodlin]

Getting the filament off ground potential solves the problem. Great idea