GM Little General

8/17/2013 3:39:39 PMLou

Guys:

Well after much work and some realignment, I now have the Little General working ( melodious too!).

However, I have one question.

This radio has three RF stages - all 24A tubes.

What is the best frequency to align the stages - the highest frequency on the dial or some intermediate frequency like 1 MHz?

I have no alignment instructions from the manufacturer but being a TRF set, they should be all similar.

Thanks
Lou

8/17/2013 4:44:19 PMNorm Leal

Lou

If you have trimmer caps they have the greatest effect at high end of the dial. Adjust there for max signal. Be sure 24A's have shields. These radios can easily go into oscillation with high RF gain.

Norm

:Guys:
:
:Well after much work and some realignment, I now have the Little General working ( melodious too!).
:
:However, I have one question.
:
:This radio has three RF stages - all 24A tubes.
:
:What is the best frequency to align the stages - the highest frequency on the dial or some intermediate frequency like 1 MHz?
:
:I have no alignment instructions from the manufacturer but being a TRF set, they should be all similar.
:
:Thanks
:Lou
:

8/18/2013 12:30:31 AMLou

Thanks Norm

Well I happen to have only one out of the three necessary shields. I am either going to have to make two more or see if I do get the oscillations you speak of. Unfortunately these appear to be "custom" shields for this radio alone. I have not seen this type of slip fit shields before.

Lou

:Lou
:
:If you have trimmer caps they have the greatest effect at high end of the dial. Adjust there for max signal. Be sure 24A's have shields. These radios can easily go into oscillation with high RF gain.
:
:Norm
:
::Guys:
::
::Well after much work and some realignment, I now have the Little General working ( melodious too!).
::
::However, I have one question.
::
::This radio has three RF stages - all 24A tubes.
::
::What is the best frequency to align the stages - the highest frequency on the dial or some intermediate frequency like 1 MHz?
::
::I have no alignment instructions from the manufacturer but being a TRF set, they should be all similar.
::
::Thanks
::Lou
::
:
:

8/18/2013 8:21:14 PMClifton

Lou,

For testing you can probably be creative and use extra heavy duty aluminum foil and wrap the tubes in for a shield. Just make sure the foil grounds to the chassis.

Clifton

:Thanks Norm
:
:Well I happen to have only one out of the three necessary shields. I am either going to have to make two more or see if I do get the oscillations you speak of. Unfortunately these appear to be "custom" shields for this radio alone. I have not seen this type of slip fit shields before.
:
:Lou
:
::Lou
::
::If you have trimmer caps they have the greatest effect at high end of the dial. Adjust there for max signal. Be sure 24A's have shields. These radios can easily go into oscillation with high RF gain.
::
::Norm
::
:::Guys:
:::
:::Well after much work and some realignment, I now have the Little General working ( melodious too!).
:::
:::However, I have one question.
:::
:::This radio has three RF stages - all 24A tubes.
:::
:::What is the best frequency to align the stages - the highest frequency on the dial or some intermediate frequency like 1 MHz?
:::
:::I have no alignment instructions from the manufacturer but being a TRF set, they should be all similar.
:::
:::Thanks
:::Lou
:::
::
::
:
: