Ferranti AF Transformers

[SurreyNick]

Does anyone have any datasheet information on the range of Ferranti Audio Frequency transformers (AF1, AF2, AF3....AF10 etc.)? The datasheet for the AF3 is available from the RadioMuseum website, but nothing else and I can't find any elsewhere.

However, Ferranti did produce datasheets for each and (I believe) they even published a short brochure which included them all.

All help appreciated.

Thanks

[yestertech]

I have a copy of the "True Road to radio"
The specs. might just be in there - will check

Andy

[SurreyNick]

Thanks Andy
Nick

[David G4EBT]

I don't know how comprehensive the Ferranti AF3 data is on the RMORG site Nick, but you can get the six-page brochure from here if it's any better:

http://www.valve-radio.co.uk/literat...3-transformer/

(Quite a lot of other data of interest at the home page on that link too).

Hope that helps a bit.

[SurreyNick]

Oh yeah, that's much better David, thanks. So that sorts out the AF3, just need something for the other nine transformers in the AF series. Help!
Nick

[dsergeant]

I couldn't see any specs on the transformers in True Road to Radio. But I have just started reading Ferranti - A History by John Wilson. There may be some references to them in there in general terms, but it will take a while to get through the 600 odd pages (and already have volume 2 of the Wilson trilogy waiting when I have finished that - I expect a lot of nostalgia as I worked for them for over 20 years).
Dave

[SurreyNick]

Thanks Dave. Do please let me know if you find any references, although I appreciate it may be some time
I bet it was an interesting company to work for.

I believe the museum of science and industry and the national archives have records relating to Ferranti and their products so I will try them too.

Nick

[Ed_Dinning]

Hi Nick, most of the Ferranti archive is at the Manchester museum of science and industry, but I'm not sure how much is catalogued.

Ed

[SurreyNick]

Thanks Ed
I'll contact them and find out.
Nick

[Dave757]

Hi

Here's one for the AF5

Kind regards

Dave

[SurreyNick]

Oooh, excellent. Thanks Dave.
I have sent you a PM in the hope you might be able to email me a larger copy too.

Two down, eight to go

Thanks again
Nick

[dsergeant]

The Ferranti A History book has a prominent photo of the AF3 on the front cover so it is a hopeful sign. I am at the moment learning about Sebastian's childhood when he was already designing steam engines at the age of 12 and telling his parents off for giving him a story book rather than an engineering book for his birthday, fascinating stuff!
Dave

[SurreyNick]

And I was only interested in fishing and girls at that age! Oh well, explains why he became who he did and I'm still a fisherman
N.

[SurreyNick]

Thanks to Dave757 and other contributors to this thread I now have datasheets for all Ferranti AF transformers except AF1, AF2, AF9 and AF10.

If anyone can help with these, especially the AF2 (which I have) I would be very grateful.

Once I have all that I can locate my hands on I will make them available to the forum.
Nick

[PJL]

I have a set to make a stereo PP triode amplifier as per the Ferranti notes (one or two need repair/rewind). As well as the air spaced coils to lower capacitance they have a compensating capacitor embedded in the primary connection block to improve the HF response. I must try them out to see what the frequency response is like.

[SurreyNick]

I wasn't really conscious of it until earlier today that Ferranti produced two versions of their AF transformers. The standard version and a push-pull version which had the letter 'c' designation after the model eg AF3c. The push-pull ones had additional taps, which is obvious really but I hadn't given it much thought. I now have a whole lot more to collect for my display!

Nick

[Ed_Dinning]

Hi Nick, Ferranti was one of the "fathers" of the transformer and his company made a wide variety of sizes and powers of transformer.
In the true road to radio book many types other than I/V types are shown for the constructor to use. A lot of these are of a similar style to I/V transformers, so look at them carefully.
Apart from the obvious mains transformers and chokes, there are several types of output transformer, single ended, push-pull, QPP, output chokes.
There are also driver transformers in single ended and push-pull varieties to drive the output valves, then input transformers for microphones and pick-up.

Quite a variety!!!

Ed

[G4XWDJim]

Originally Posted by SurreyNick

If anyone can help with these, especially the AF2 (which I have) I would be very grateful.

I have several of these transformers that I'd like to identify. They seem to have lost their identifying marks and numbers over the years so it will be a case I imagine of identifying them by measuring their resistance and calculating their ratios either with an audio sig gen or low voltage AC.

I would be grateful if you can make the information available here.

Jim

[SurreyNick]

Happy to do so Jim. I had intended to wait until I had a full suite but if you'd like what I have currently PM me your email address and I will forward them to you
Nick

[G4XWDJim]

Pm on it's way Nick,

Many thanks,

Jim