Hello Everyone,
I got my hands on Riders page 20-65 & 20-66 Sears,
Roebuck Model 9005 Ch. 132.858. The schematic shows output xfmr p/n to be N22193-1. Can anyone tell me what this crosses to or what values I need to look for in a replacement xfmr. I don't see any spec reference in the 2 pgs I have.
Thanks,
Sam

Hi Sam

Your radio uses a 50L6GT output. This determines the output transformer. Look for an output transformer with primary of 2,000 ohm impedance. DC resistance will be much less. Seconday should match your speaker, probably 4 ohm? Not critical..

AES, www.tubesandmore.com and PTOP, www.oldradioparts.com , both sell replacements.

You will need to connect the bottom two leads shown on your radio primary. Replacement transformers won't have this extra winding. This winding was just a few turns of wire to cancel hum.

Norm

:Hello Everyone,
:I got my hands on Riders page 20-65 & 20-66 Sears,
:Roebuck Model 9005 Ch. 132.858. The schematic shows output xfmr p/n to be N22193-1. Can anyone tell me what this crosses to or what values I need to look for in a replacement xfmr. I don't see any spec reference in the 2 pgs I have.
:Thanks,
:Sam

Norm
Thanks for the follow up. I'm not quite sure i understand what you mean by connecting the 2 bottom leads. Could you explain?
Sam
:Hi Sam
:
: Your radio uses a 50L6GT output. This determines the output transformer. Look for an output transformer with primary of 2,000 ohm impedance. DC resistance will be much less. Seconday should match your speaker, probably 4 ohm? Not critical..
:
: AES, www.tubesandmore.com and PTOP, www.oldradioparts.com , both sell replacements.
:
: You will need to connect the bottom two leads shown on your radio primary. Replacement transformers won't have this extra winding. This winding was just a few turns of wire to cancel hum.
:
:Norm
:
::Hello Everyone,
::I got my hands on Riders page 20-65 & 20-66 Sears,
::Roebuck Model 9005 Ch. 132.858. The schematic shows output xfmr p/n to be N22193-1. Can anyone tell me what this crosses to or what values I need to look for in a replacement xfmr. I don't see any spec reference in the 2 pgs I have.
::Thanks,
::Sam

Sam

The schematic I looked at had B+ from the rectifier going to one lead of the output transformer. Another lead, near bottom of the transformer schematic, sends B+ to the test of your radio. This is a hum cancelling winding. It wasn't used in most radios. Replacement transformers won't have this extra winding. It's not a center tap but rather just few turns of wire.

Connect these two wires together when replacing the output transformer. The radio will operate.

Norm
:Norm
:Thanks for the follow up. I'm not quite sure i understand what you mean by connecting the 2 bottom leads. Could you explain?
:Sam
::Hi Sam
::
:: Your radio uses a 50L6GT output. This determines the output transformer. Look for an output transformer with primary of 2,000 ohm impedance. DC resistance will be much less. Seconday should match your speaker, probably 4 ohm? Not critical..
::
:: AES, www.tubesandmore.com and PTOP, www.oldradioparts.com , both sell replacements.
::
:: You will need to connect the bottom two leads shown on your radio primary. Replacement transformers won't have this extra winding. This winding was just a few turns of wire to cancel hum.
::
::Norm
::
:::Hello Everyone,
:::I got my hands on Riders page 20-65 & 20-66 Sears,
:::Roebuck Model 9005 Ch. 132.858. The schematic shows output xfmr p/n to be N22193-1. Can anyone tell me what this crosses to or what values I need to look for in a replacement xfmr. I don't see any spec reference in the 2 pgs I have.
:::Thanks,
:::Sam