05-23-2017, 10:07 AM
Tnx Kman!
Tube came in the other day so I unsolder the diode and installed the 117Z6 and no dice... So measured voltage and found that the filament string was at 7.5v, not good. Portables with low volt/low current tubes need to be pretty close to the proper filament voltage . In this case it require 9-9.5v to operate. Ended up adding a 20K@2w in parallel with the 1700 ohm filament dropping resistor giving me 9.1v.
As an aside my line volt here is fairly low @113vac
On the schematic it shows a dial light (used in ac operation only) but this set shows no sign of having one. I wired up a bulb and it does work just have to fashion a mounting bracket.
Tube came in the other day so I unsolder the diode and installed the 117Z6 and no dice... So measured voltage and found that the filament string was at 7.5v, not good. Portables with low volt/low current tubes need to be pretty close to the proper filament voltage . In this case it require 9-9.5v to operate. Ended up adding a 20K@2w in parallel with the 1700 ohm filament dropping resistor giving me 9.1v.
As an aside my line volt here is fairly low @113vac
On the schematic it shows a dial light (used in ac operation only) but this set shows no sign of having one. I wired up a bulb and it does work just have to fashion a mounting bracket.
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry
