Just wondering if anybody may have come across this transformer or hopefully have a catalogue page with the data for it.

I have searched the Rola catalogue on KC's website but this refers only to valve radio and amplifier transformers.

https://www.kevinchant.com/uploads/7/1/0/8/7108231/rola_tech_data.pdf

This tiny transformer would probably be from the 60's and I am fairly sure it is a push-pull output transformer going by the winding resistances.

These are the details;
Centre-tapped winding (transistor push-pull side) measuring 15 Ohms per side. Wire colours Blue - Red (ct) - Brown
Speaker winding measures 0.95 Ohms. Wire colours Green - Black

My guess is that the transformer is for a speaker impedance of 8 Ohms and the primary impedance would be around 350 - 400 Ohms 400Hz. Power rating would be no more than 200mW.

Regards to all
Ross

Sounds like a Jaycar MM2530 1K Center taped to 8 ohms, 300mW would probably do the trick.
Or if you use a 15 ohm speaker it would become an approx 2K CT/15. etc.
JJ

Thanks for the tip Johnny - will check out the Jaycar transformer for comparison.

Actually, I wanted a real copy of a pamphlet or data sheet for the Rola JTR27 mainly because it is brand new and still in its original carton. Sort of a collectable item perhaps...

I just had a look at a Rola/Plessey Loudspeaker Data guide.

All it says for the JTR27 is that is a output transformer, 450 CT/15. There are no other details, pictures or dimensions.

Hi MonochromeTV,

The 15 Ohm secondary impedance is good to know.

I managed to borrow an LCR meter and discovered the primary inductance 1kHz was 65mH per side which means the 450 Ohms would be about right.

Would you be able to make the Plessey-Rola data catalogue available?