Old OP Transformer

[PeteMcK]

Guys,

Found an old (early 50s?) 'Cinevox" Projector amp on the side of the road, nothing useful except the transformers & valve sockets.
The OPT measures 400 + 400 ohms primary, and 56 Ohms secondary. The Primary seems ball park, but the secondary seems too high for normal speaker loads. Comparable tramsformers I have for 15 ohm speakers measure 2-3 ohms.

My guess is that this is for some sort of Higher Z load?
Cross section area of core is about 1" sq - can probably handle about 10W?

Any alternative theories?
Pete McK

 

[Frank Berry]

The amplifier may actually be a preamp with balanced a 600 ohm output.
What are the tube types?

 

[SHiFTY]

What are the markings on the outside? Does it have an internal speaker?

 

[TonyTecson]

could be 70.7 volts output for long cable runs.....

 

[Frank Berry]

"could be 70.7 volts output for long cable runs....."

Perhaps but isn't the transformer rather small?

 

[PeteMcK]

tube

The only tube left in it had the part code partly scratched out, but I think it's a 6C5 or 6L5, has a metal can; there are 7 octal sockets, in a layout which is really bad for heat dissipation.
There is also a power transformer and a large choke. The build quality isn't very good.
"could be 70.7 volts output for long cable runs" - I'm thinking it's for something like this, 10 W was a lot of power back in 1950!!!

Perhaps I should think about using this transformer for inter-stage use?

Thanks for the input,
Pete McK