What in the heck was the purpose of this 790ohm ballast tube? (Do they use a regular #47 pilot lamp?)
It just feeds the pilot lamp and they do not use the pilot lamp tap on the rectifier... duh?
Just to add another tube value?
http://www.nostalgiaair.org/PagesByModel/958/M0014958.pdf

:What in the heck was the purpose of this 790ohm ballast tube? (Do they use a regular #47 pilot lamp?)
:It just feeds the pilot lamp and they do not use the pilot lamp tap on the rectifier... duh?
:Just to add another tube value?
:http://www.nostalgiaair.org/PagesByModel/958/M0014958.pdf

That just has to be one of the dumbest ideas I have seen in a while. An expensive way of powering a pilot light.
Lewis

:That just has to be one of the dumbest ideas I have seen in a while. An expensive way of powering a pilot light.
:Lewis

Maybe not so dumb in some respects. How many of us have blown taps on a rectifier because the pilot light was burned out? In the long run a saved rectifier or two would be worth the cost of the ballast, no?

::That just has to be one of the dumbest ideas I have seen in a while. An expensive way of powering a pilot light.
::Lewis
:
:Maybe not so dumb in some respects. How many of us have blown taps on a rectifier because the pilot light was burned out? In the long run a saved rectifier or two would be worth the cost of the ballast, no?

Yeah, I had thought about that, but it sure seems an expensive way to light up a bulb.
Lewis

Hi All,
It does look odd, but I suspect that the 50L6GT had been a 35L6GT in an earlier design. This may have been a work around at a time when 35L6GT got scarce.

Best Regards,

Bill Grimm

I vote for added tube count. The radio already has a 35Z5 which is made to operate a lamp. Don't think this will save the filament tap of 35Z5 either. Tap usually goes due to bad filter caps or tube arcing. Since there isn't a lamp and tap to act as a fuse something else has to go. The 35Z5 is connected directly to the AC line, no resistance.

Norm

:Hi All,
: It does look odd, but I suspect that the 50L6GT had been a 35L6GT in an earlier design. This may have been a work around at a time when 35L6GT got scarce.
:
:Best Regards,
:
:Bill Grimm

Hi Norm,
I must say, I haven't found the design variant that has the 35L6GT in it.

Best Regards,

Bill Grimm

Hi Bill

In order to use a 35L6 in place of 50L6 there should be series resistance added in the filament line. Philco did this is some radios. The idea being a resistor takes most of the turn on surge.

If the radio doesn't have series resistance someone substituted the wrong tube. Either tube will work but with 35L6 there will be extra voltage across each filament.

Norm

:Hi Norm,
: I must say, I haven't found the design variant that has the 35L6GT in it.
:
:Best Regards,
:
:Bill Grimm