'The BURTON' Driver Transformer - Info ?

[Newmarket]

Hello 'Hive'
So I know lots around opamps / impedance / 'balancing' etc etc - it's how I earn a crust - but I'll happily admit that magnetics - and in the context here Audio Transformers -is not an area where I have a lot of expertise.
But over the last few years I've used more transformers for isolation and Impedance transformation (eg DI) purposes on a personal/hobby level.
So I've picked up a few 'mystery transformers' that I haven't been able to find a lot (or any tbh) info' on.
First up - this one - (see pics).
I can't take any Inductance measuremnts atm - but could next week when back at work - but the DCRs are:

On the two terminal side (designated HT+ / Plate) = 452 Ohm
Three Terminal Side: (designated G/LT/G) = 176.8 / 223.2 Ohm (G to G = 400 Ohm)

Any info' / advice appreciated.

Apart from that it's just aesthetically pleasing

 

[Youngwhisk]

If that is the one from eBay late July, one of the pictures showed the ratio on the bottom. Possibly 1.5-1

 

[ruffrecords]

This looks like a push pull stage driver transformer possibly for a battery powered device of some sort. LT stands for low tension (i.e. heaters) and obviously G is for grid. Probably directly heated tubes too.

Cheers

Ian

 

[Newmarket]

If that is the one from eBay late July, one of the pictures showed the ratio on the bottom. Possibly 1.5-1

Yes it is. At least the timeline fits and I haven't seen another. I missed the bottom marking as I didn't look under s "Thank You" Post-It that the seller placed there.

 

[Newmarket]

This looks like a push pull stage driver transformer possibly for a battery powered device of some sort. LT stands for low tension (i.e. heaters) and obviously G is for grid. Probably directly heated tubes too.

Cheers

Ian

Thanks for that info Ian.

 

[Newmarket]

Another transformer. More info on this unit but anything further appreciated.

 

[scott2000]

Came across this page...Maybe a way to reach out to them?

https://www.radioexperimenter.us/chicago-radio-catalog/audio-transformers.html

 

[Newmarket]

Came across this page...Maybe a way to reach out to them?

https://www.radioexperimenter.us/chicago-radio-catalog/audio-transformers.html

Thanks. I'll follow it up.

 

[MisterCMRR]

Actually, the label says a lot about this one. Both 10,000 Ω to 10 Ω and 2,500 to 2.5 Ω are 100:1 impedance ratio. Since turns ratio is always the square root of impedance ratio, it makes this a 31.6:1 transformer. But it has dual primary and secondary windings. You can test the DCR of each winding and you should find two that are near-equal likely in hundreds of ohms, and two that are near-equal of only a few ohms. To use with 10 kΩ input, put the similar windings in series, and for 2.5 kΩ input, use them in parallel. But you'll have to establish the "polarity" of the windings (i.e., the schematic "dot" showing ends of same polarity). Easiest way to do this is with a generator and oscilloscope. Drive one of the primary windings with the generator, being sure to sync the scope to the generator, not the scope input channel you're viewing! Then you can look at each of the windings, including the one you're driving as a reference, to see the matching polarity connections. Also, the label says 5 mA DC rating. This would be primary DC for a single-ended tube driver ... but it's not clear whether that applies to the series or parallel connection.

 

[ruffrecords]

I suspect is is a push pull output with the 10K being plate to plate impedance with the 5mA probably referring to the allowed dc imbalance between windings. Note the dB level is quoted as 40 which is 10 watts.

Cheers

Ian

 

[Brian Roth]

Ian, maybe my old eyes are failing me, but it sure looks like the dB Level marking is "0" rather than 40.

Hmmmmm....

Bri

 

[ruffrecords]

Ian, maybe my old eyes are failing me, but it sure looks like the dB Level marking is "0" rather than 40.

Hmmmmm....

Bri

On the first pic it does look like that, but he second pic, the close up, when clicked on to enlarge, definitely looks like 40 to me. There is definitely something to the left of the zero but my eyes are as old as yours and definitely not to be relied on for critical viewing

Cheers

Ian

 

[Newmarket]

Actually, the label says a lot about this one. Both 10,000 Ω to 10 Ω and 2,500 to 2.5 Ω are 100:1 impedance ratio. Since turns ratio is always the square root of impedance ratio, it makes this a 31.6:1 transformer. ...

Thanks for that input. Small point it should be 1000:1 impedance ratio (rather than 100:1). I guess it's just a typo'.

 

[Newmarket]

Ian, maybe my old eyes are failing me, but it sure looks like the dB Level marking is "0" rather than 40.

Hmmmmm....

Bri

On the first pic it does look like that, but he second pic, the close up, when clicked on to enlarge, definitely looks like 40 to me. There is definitely something to the left of the zero but my eyes are as old as yours and definitely not to be relied on for critical viewing

Cheers

Ian

I think the stamping says "+0"

But I don't have it to hand atm so I'll check later.

 

[Brian Roth]

Oops.....I meant to write that my old eyes saw "+0" whatever that means. Hence my Hmmmmm in the earlier post. <g>

Bri

 

[ruffrecords]

Oops.....I meant to write that my old eyes saw "+0" whatever that means. Hence my Hmmmmm in the earlier post. <g>

Bri

I have blown the pic up and I can now see that you are indeed correct. It does say +0 so forget everything I said about 10W etc.

Cheers

Ian

 

[Newmarket]

I have blown the pic up and I can now see that you are indeed correct. It does say +0 so forget everything I said about 10W etc.

Cheers

Ian

Yes - just checked and it's "+0".
Of course, the "+" is meaningless with 'Zero' but I guess it's just a convention.
Cheers.