BBC Transformers

[Guest]

Bought the following model from Canford for a pittance (£3.50) - BTW check out their second hand/shop soiled offers (as well as their clearance offers) - B- gauge patchbay for £25!!!!

Back to the problem...
So I now have a 1 1/2 inch tall "open coil" transformer (bigger than I thought) with the following characterstics
LL228 2PE
Impedence Ratio 2:1
Primary Inductance 5
Winding Resistance Primary 7 ohms
Winding Resistance Secondary 3.5 ohms

What can I use it for (apart for a paper weight?)

 

[NewYorkDave]

600:300 line level (if it really is a 2:1 impedance ratio) or 600:150 (if you really meant to say "turns ratio").

You want details on how I came to that conclusion, or did you just want the answer?

 

[rafafredd]

Or 150:600, 312 output iron.

 

[gyraf]

or as a 150:600 output transformer, giving +6dB more max. output if your circuit run at low voltage, e.g.+/-12V

 

[Guest]

[quote author="NewYorkDave"]600:300 line level (if it really is a 2:1 impedance ratio) or 600:150 (if you really meant to say "turns ratio").

You want details on how I came to that conclusion, or did you just want the answer?[/quote]
originally just the answer - but now I am intrigued

 

[rafafredd]

5H is what you usually have for audio frequency transformers at 600ohms winding.

 

[NewYorkDave]

Yes, 5H or greater.

Inductive reactance is 2pi(fL). So at the lowest frequency of interest

6.28(20 * 5) = 628 ohms.

UK said a 2:1 impedance ratio, which would indicate a 600:300 transformer. But if what he really meant is a 2:1 turns ratio, then it's a 600:150 transformer.

Lastly, the physical size and the lack of shielding indicates a line level transformer.

 

[Guest]

[quote author="NewYorkDave"]Yes, 5H or greater.

Inductive reactance is 2pi(fL). So at the lowest frequency of interest

6.28(20 * 5) = 628 ohms.

UK said a 2:1 impedance ratio, which would indicate a 600:300 transformer. But if what he really meant is a 2:1 turns ratio, then it's a 600:150 transformer.

Lastly, the physical size and the lack of shielding indicates a line level transformer.[/quote]
All I am doing is quoting from the catalogue
Here is the pdf
http://www.canford.co.uk/commerce/resources/catdetails/2743.pdf
In the picture it's the middle on in the second row...
I am awaiting more info from canford

 

[rafafredd]

You say it´s a BIG iron... Maybe it´s gapped?