Speaker Output Transformer

[Danndad]

Can anybody help with a speaker output transformer off of a Japanese valve radio?  Primary is OC.  Price to include postage to Cornwall please.

It will only allow me to add one picture for some reason, I will try and add some more later.

Danndad

   

[boater sam]

What is the output valve and the impedance of the speaker?

If all else fails a rewind is possible, I am in Cheshire but the postal service will recover after Christmas, hopefully.

[Danndad]

Thanks for the reply Sam.
The output valve is a 50C5 and there are two 3ohm speakers wired in series.
I bet a rewind price is shocking.

http://www.r-type.org/exhib/abo0115.htm

[boater sam]

Not necessarily shocking but it depends on your shock level!
I rewind output transformers for the likes of DAC90A Bush sets and they cost me around £6 to £10  in materials. My time is free of course.
This set needs a transformer of about 20:1 ratio. You could try a small 240v to 12v mains transformer, about the same ratio, and it should work just fine.

[Mike Watterson]

This set needs a transformer of about 20:1 ratio. You could try a small 240v to 12v mains transformer, about the same ratio, and it should work just fine.

The "trick" is to use a larger one than the dead audio transformer to avoid the bias current saturating the core.

I've even bought cheap clock radios out of Tesco, Argos or a charity shop to use the small mains transformer as audio on a battery valve radio.

[Danndad]

I've sent you a PM Sam.

[boater sam]

This transformer has been rewound.  It was a fiddly job, being so small.  Only 2428 turns!  On a 1/2" waxed bobbin!

Must of been a very marginal design form new.

Sam.

[Danndad]

Transformer back from Sam today, will fit in the coming days.

[Danndad]

Big thanks to Boater Sam.
Transformer in and working well.