Although it is labeled as model 57K made in Canada, the closest schematic I can find is a model 57 with the identical tube lay out. The speaker is missing, can someone advise how to go about replacing the original with a permanent magnet type? Thanks.

Brian: Here is your schematic? http://www.nostalgiaair.org/PagesByModel/739/M0029739.pdf

The field coil resistance is listed as 2K for a Model 57K.

You can replace the field coil with a 2K power resistor. Add up the total plate current for all the tubes, double it, and then figure the minimum power rating for the resistor, using tube data for plate current.

Is the audio xfmr present, or was it part of the missing speaker? If xfmr not present, use just about any-old audio xfmr to connect to the modern PM speaker.
Doug

:Although it is labeled as model 57K made in Canada, the closest schematic I can find is a model 57 with the identical tube lay out. The speaker is missing, can someone advise how to go about replacing the original with a permanent magnet type? Thanks.

Thanks. Quite a few of my radios have a four prong speaker plug, two larger pins and two smaller ones. Was there any standardization to these, the larger ones being perhaps the speaker coil?

:Brian: Here is your schematic? http://www.nostalgiaair.org/PagesByModel/739/M0029739.pdf
:
:The field coil resistance is listed as 2K for a Model 57K.
:
:You can replace the field coil with a 2K power resistor. Add up the total plate current for all the tubes, double it, and then figure the minimum power rating for the resistor, using tube data for plate current.
:
:Is the audio xfmr present, or was it part of the missing speaker? If xfmr not present, use just about any-old audio xfmr to connect to the modern PM speaker.
:Doug
:
:
::Although it is labeled as model 57K made in Canada, the closest schematic I can find is a model 57 with the identical tube lay out. The speaker is missing, can someone advise how to go about replacing the original with a permanent magnet type? Thanks.

I don't know the answer. But you should be able to figure them out with an ohmmeter. Also, some schematics show a diagram of the speaker plug/socket pinouts.
Doug

:Thanks. Quite a few of my radios have a four prong speaker plug, two larger pins and two smaller ones. Was there any standardization to these, the larger ones being perhaps the speaker coil?
:

I'll make this statement without reviewing the diagrams, but big pins equal field coil.

:I don't know the answer. But you should be able to figure them out with an ohmmeter. Also, some schematics show a diagram of the speaker plug/socket pinouts.
:Doug
:
::Thanks. Quite a few of my radios have a four prong speaker plug, two larger pins and two smaller ones. Was there any standardization to these, the larger ones being perhaps the speaker coil?
::
:

Bill, what book did that info come out of?
Doug

:I'll make this statement without reviewing the diagrams, but big pins equal field coil.
:
:
:
::I don't know the answer. But you should be able to figure them out with an ohmmeter. Also, some schematics show a diagram of the speaker plug/socket pinouts.
::Doug
::
:::Thanks. Quite a few of my radios have a four prong speaker plug, two larger pins and two smaller ones. Was there any standardization to these, the larger ones being perhaps the speaker coil?
:::
::

Hi Doug,
It's Radio Troubleshooter's Handbook, 3rd ed.,1943, Alfred A. Ghirardi.
Bill

:Bill, what book did that info come out of?
:Doug
:
::I'll make this statement without reviewing the diagrams, but big pins equal field coil.
::
::
::
:::I don't know the answer. But you should be able to figure them out with an ohmmeter. Also, some schematics show a diagram of the speaker plug/socket pinouts.
:::Doug
:::
::::Thanks. Quite a few of my radios have a four prong speaker plug, two larger pins and two smaller ones. Was there any standardization to these, the larger ones being perhaps the speaker coil?
::::
:::

Thanks, Bill. I know I have one book by Ghirardi. I'll have to dig it out.
Doug

:Hi Doug,
:It's Radio Troubleshooter's Handbook, 3rd ed.,1943, Alfred A. Ghirardi.
:Bill
:
::Bill, what book did that info come out of?
::Doug
::
:::I'll make this statement without reviewing the diagrams, but big pins equal field coil.
:::
:::
:::
::::I don't know the answer. But you should be able to figure them out with an ohmmeter. Also, some schematics show a diagram of the speaker plug/socket pinouts.
::::Doug
::::
:::::Thanks. Quite a few of my radios have a four prong speaker plug, two larger pins and two smaller ones. Was there any standardization to these, the larger ones being perhaps the speaker coil?
:::::
::::

Thanks to you both, Bill and Doug, for your assistance. Brian

:Thanks, Bill. I know I have one book by Ghirardi. I'll have to dig it out.
:Doug
:
::Hi Doug,
::It's Radio Troubleshooter's Handbook, 3rd ed.,1943, Alfred A. Ghirardi.
::Bill
::
:::Bill, what book did that info come out of?
:::Doug
:::
::::I'll make this statement without reviewing the diagrams, but big pins equal field coil.
::::
::::
::::
:::::I don't know the answer. But you should be able to figure them out with an ohmmeter. Also, some schematics show a diagram of the speaker plug/socket pinouts.
:::::Doug
:::::
::::::Thanks. Quite a few of my radios have a four prong speaker plug, two larger pins and two smaller ones. Was there any standardization to these, the larger ones being perhaps the speaker coil?
::::::
:::::