something cool.

I came across this old telegraph switchboard transformer at a yard sale. It has no markings or patent numbers.
Surely there could be an audio application for it. Any thoughts?

ReRibbon said:

I came across this old telegraph switchboard transformer at a yard sale. It has no markings or patent numbers.
Surely there could be an audio application for it. Any thoughts?

Click to expand...

Cool! What do the coils measure in OHMS. Might work as a Carbon Button Mic Transformer?

The side with two lugs reads 44.4 ohms.
The side with three lugs reads outside left to center lug 24.3 ohms.
The same is read for the outside right side and center lugs.
The outside two lugs measured together reads 42.6 ohms.

There may be some numbers stamped into the top and/or bottom flanges. There could be some information on one of the WECo transformer  links on this page:

http://www.telephonecollectors.info/index.php/browse/cat_view/92-wiring-diagrams-technical-library/142-western-electric/335-component-specifications

Thanks for the link. I couldn't really find anything.
There is this stamp, but it's not all that clear.

ReRibbon said:

The side with two lugs reads 44.4 ohms.
The side with three lugs reads outside left to center lug 24.3 ohms.
The same is read for the outside right side and center lugs.
The outside two lugs measured together reads 42.6 ohms.

Click to expand...

Seems to me like a 600:600 repeater with a center-tapped; the center-tap was used for creating a third "phantom" connection out of two balanced lines, allowing three links with two balanced lines.
These  were designed for voice range 300Hz-3.5kHz