Hi, I have 2 different schematics for this radio and have a question about 2 of the tubes. In the Photo Fact schematic it says to use a 12SG7 semi remote cut off RF Pentode in socket #2 and a 12J5 Med Mu Triode in socket #3. In the other schematic John F. Rider it says to use a 12SK7 Remote Cut off Pentode in socket #2 and either a 12H6 Duo Diode or 12J5 in socket #3. The radio currently has the Rider schematic tubes in it the 12SK7 and the 12H6 both are metal tubes. There are a couple things I have to take care of one socket possibly is loose and a OOT resistor. Was kind of wondering if the tube configuration could be causing the problem with the static I'm getting after a hour or so of playing the radio. Thanks Again, George.

Hi George

12SK7 and 12SG7 are usually interchangeable. A 12J5 and 12H6 could be interchangeable if the tube is used as a detector? This tube will be using pins #5 and #8.

Around WW2 manufacturers used whatever tubes they could get. Not unusual for the same model to have different tubes.

Type of tubes are not causing a problem. Most likely a leaky cap?

Norm

:Hi, I have 2 different schematics for this radio and have a question about 2 of the tubes. In the Photo Fact schematic it says to use a 12SG7 semi remote cut off RF Pentode in socket #2 and a 12J5 Med Mu Triode in socket #3. In the other schematic John F. Rider it says to use a 12SK7 Remote Cut off Pentode in socket #2 and either a 12H6 Duo Diode or 12J5 in socket #3. The radio currently has the Rider schematic tubes in it the 12SK7 and the 12H6 both are metal tubes. There are a couple things I have to take care of one socket possibly is loose and a OOT resistor. Was kind of wondering if the tube configuration could be causing the problem with the static I'm getting after a hour or so of playing the radio. Thanks Again, George.

Hi George,
Static after operating a while? What do you think about the resistor heating up and being "noisy" because it is out of tolerance. Noise could be from the socket. You might could probe around and fine a loose solder connection too.
Bill

:Hi George
:
: 12SK7 and 12SG7 are usually interchangeable. A 12J5 and 12H6 could be interchangeable if the tube is used as a detector? This tube will be using pins #5 and #8.
:
: Around WW2 manufacturers used whatever tubes they could get. Not unusual for the same model to have different tubes.
:
: Type of tubes are not causing a problem. Most likely a leaky cap?
:
:Norm
:
::Hi, I have 2 different schematics for this radio and have a question about 2 of the tubes. In the Photo Fact schematic it says to use a 12SG7 semi remote cut off RF Pentode in socket #2 and a 12J5 Med Mu Triode in socket #3. In the other schematic John F. Rider it says to use a 12SK7 Remote Cut off Pentode in socket #2 and either a 12H6 Duo Diode or 12J5 in socket #3. The radio currently has the Rider schematic tubes in it the 12SK7 and the 12H6 both are metal tubes. There are a couple things I have to take care of one socket possibly is loose and a OOT resistor. Was kind of wondering if the tube configuration could be causing the problem with the static I'm getting after a hour or so of playing the radio. Thanks Again, George.

Thank You for your much needed help. I just finished replacing all of the resistors. I'm about a 100 percent sure there are a couple of sockets that need attention. I will cross that bridge tomorrow night. I lubed the slugs they seem to be fine. Once again Thank You for your help will let you know what I find. George