Greetings; I just acquired a GTC Model H battery eliminator. It uses a 6J5GT tube.

The "A+" voltage is 1.5 VDC, which it is supposed to be. However, the "B+" voltage is 45 VDC, which is exactly half the value (90 VDC) it is supposed to be. I know old battery eliminators, and indeed all old electronics can deteriorate over time, but is it unusual for voltage to be exactly half? Does anyone have any ideas as to what might be the problem? Where I can start to check? As you can tell I'm new to radios and am starting to grasp the basics.

Thanks,
Jim

:Greetings; I just acquired a GTC Model H battery eliminator. It uses a 6J5GT tube.
:
:The "A+" voltage is 1.5 VDC, which it is supposed to be. However, the "B+" voltage is 45 VDC, which is exactly half the value (90 VDC) it is supposed to be. I know old battery eliminators, and indeed all old electronics can deteriorate over time, but is it unusual for voltage to be exactly half? Does anyone have any ideas as to what might be the problem? Where I can start to check? As you can tell I'm new to radios and am starting to grasp the basics.
:
:Thanks,
:Jim

Jim:
I would need a schematic to be sure, but a 6J5 doesn't seem right. Maybe there should be a rectifier tube in that place, a rectifier that hat pins 2&7 for filament, 8 for cathode, and 3 for one plate. That would make a 6J5 give you half a rectifier and half the voltage. I need to know more to guess more.

Lewis L.

Sears used similiar circuits in their 5302 and 5303 power shifter units using a 6P5GT (which could be subbed by a 6J5GT) as a half wave rectifier as Lewis said. Under no load conditions the B+ should be higher than 90 volts. Check out/replace
the caps in the B+ circuit, check the transformer AC plate supply voltage and test/sub the 6j5 if possible.

Here's alink to those Sears power shifter schematics

http://www.nostalgiaair.org/Resources/244/M0017244.htm

http://www.nostalgiaair.org/Resources/245/M0017245.htm

Br
Ken

:Sears used similiar circuits in their 5302 and 5303 power shifter units using a 6P5GT (which could be subbed by a 6J5GT) as a half wave rectifier as Lewis said. Under no load conditions the B+ should be higher than 90 volts. Check out/replace
:the caps in the B+ circuit, check the transformer AC plate supply voltage and test/sub the 6j5 if possible.
:
:Here's alink to those Sears power shifter schematics
:
:http://www.nostalgiaair.org/Resources/244/M0017244.htm
:
:http://www.nostalgiaair.org/Resources/245/M0017245.htm
:
:
:Br
:Ken
:

Hello:
I have a Porta Power battery eliminator I acquired with a model 80B Sentinal battery radio{1939 model]. On the inside bottem chassis cover was somewhat of a schematic.I finally got it to work. It used a 5W4,a selenium rectifier,three large electrilydics and a voltage divider.The selenium rectifier was completely gone .I replaced it with a bridge and replaced the three caps and oart of the votage divider resisters and it seems to work fine.
If you Email me I will send a copy of the print that I have. good luck. If you decide not to repair it I might buy it.

::Sears used similiar circuits in their 5302 and 5303 power shifter units using a 6P5GT (which could be subbed by a 6J5GT) as a half wave rectifier as Lewis said. Under no load conditions the B+ should be higher than 90 volts. Check out/replace
::the caps in the B+ circuit, check the transformer AC plate supply voltage and test/sub the 6j5 if possible.
::
::Here's alink to those Sears power shifter schematics
::
::http://www.nostalgiaair.org/Resources/244/M0017244.htm
::
::http://www.nostalgiaair.org/Resources/245/M0017245.htm
::
::
::Br
::Ken
::
:
:
: Hello:
: I have a Porta Power battery eliminator I acquired with a model 80B Sentinal battery radio{1939 model]. On the inside bottem chassis cover was somewhat of a schematic.I finally got it to work. It used a 5W4,a selenium rectifier,three large electrilydics and a voltage divider.The selenium rectifier was completely gone .I replaced it with a bridge and replaced the three caps and oart of the votage divider resisters and it seems to work fine.
:If you Email me I will send a copy of the print that I have. good luck. If you decide not to repair it I might buy it.

After finally finding a schematic (here at Nostalgia under Sears 5302 and 5303, I finally concluded that, yes indeed they used a 6J5 for a half-wave rectifier. As their notes indicate, it only takes a little load to drag the Voltage down to 90 Volts. If the 6J5 is good, then the filter caps might be leaking and dragging the Voltage down. As for that copper oxide rectifier in the filament supply, your guess is as good as mine as to how efficiently it rectifies. Replacing with silicon might give too much filament Voltage. But anyway, this thing is for playing a battery operated radio on AC, so it isn't going to be a very high current device.
Lewis L.

::Sears used similiar circuits in their 5302 and 5303 power shifter units using a 6P5GT (which could be subbed by a 6J5GT) as a half wave rectifier as Lewis said. Under no load conditions the B+ should be higher than 90 volts. Check out/replace
::the caps in the B+ circuit, check the transformer AC plate supply voltage and test/sub the 6j5 if possible.
::
::Here's alink to those Sears power shifter schematics
::
::http://www.nostalgiaair.org/Resources/244/M0017244.htm
::
::http://www.nostalgiaair.org/Resources/245/M0017245.htm
::
::
::Br
::Ken
::
:
:
: Hello:
: I have a Porta Power battery eliminator I acquired with a model 80B Sentinal battery radio{1939 model]. On the inside bottem chassis cover was somewhat of a schematic.I finally got it to work. It used a 5W4,a selenium rectifier,three large electrilydics and a voltage divider.The selenium rectifier was completely gone .I replaced it with a bridge and replaced the three caps and oart of the votage divider resisters and it seems to work fine.
:If you Email me I will send a copy of the print that I have. good luck. If you decide not to repair it I might buy it.

:::Sears used similiar circuits in their 5302 and 5303 power shifter units using a 6P5GT (which could be subbed by a 6J5GT) as a half wave rectifier as Lewis said. Under no load conditions the B+ should be higher than 90 volts. Check out/replace
:::the caps in the B+ circuit, check the transformer AC plate supply voltage and test/sub the 6j5 if possible.
:::
:::Here's alink to those Sears power shifter schematics
:::
:::http://www.nostalgiaair.org/Resources/244/M0017244.htm
:::
:::http://www.nostalgiaair.org/Resources/245/M0017245.htm
:::
:::
:::Br
:::Ken
:::
::
::
:: Hello:
:: I have a Porta Power battery eliminator I acquired with a model 80B Sentinal battery radio{1939 model]. On the inside bottem chassis cover was somewhat of a schematic.I finally got it to work. It used a 5W4,a selenium rectifier,three large electrilydics and a voltage divider.The selenium rectifier was completely gone .I replaced it with a bridge and replaced the three caps and oart of the votage divider resisters and it seems to work fine.
::If you Email me I will send a copy of the print that I have. good luck. If you decide not to repair it I might buy it.