|
Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets. |
|
Thread Tools |
29th Oct 2018, 1:47 am | #1 |
Retired Dormant Member
Join Date: Oct 2018
Location: Manchester, UK.
Posts: 2
|
Ferranti Audio Frequency Transformers
Hello!
I have acquired two Ferranti audio frequency transformers. One is in a box, it says it's an A.F.6. tTe other looks like it has previously been taken apart and reassembled, although I can't be sure as I literally know nothing about these items. I was just wondering if anyone can give me any info on what they were used for and what they may be worth. They are interesting looking pieces, but that's just about all I can tell about them! Thank you for your time. |
29th Oct 2018, 10:02 am | #2 |
Heptode
Join Date: Jun 2017
Location: Southport, Merseyside, UK.
Posts: 646
|
Re: Ferranti Audio Frequency Transformers
If you key " Ferranti Audio Frequency Transformers A.F. 6 " into google, a range of links comes up. There appears to be a number of items in the AF 1 and upwards series.
__________________
Time flies like an arrow, fruit flies like a banana |
29th Oct 2018, 11:39 am | #3 |
Nonode
Join Date: Mar 2008
Location: Aberdeen, UK.
Posts: 2,857
|
Re: Ferranti Audio Frequency Transformers
Phil,
They were used in battery powered TRF Rx's from the 1920's & early 30's. Regards, David |
29th Oct 2018, 4:01 pm | #4 |
Dekatron
Join Date: Aug 2007
Location: W.Butterwick, near Doncaster UK.
Posts: 8,935
|
Re: Ferranti Audio Frequency Transformers
Main point,put an Ohms meter across to make sure they are not open circuit.
__________________
G8JET BVWS Archivist and Member V.M.A.R.S |
29th Oct 2018, 4:27 pm | #5 |
Retired Dormant Member
Join Date: Oct 2018
Location: Manchester, UK.
Posts: 2
|
Re: Ferranti Audio Frequency Transformers
Thanks for the info, everyone!
Does anybody have any idea of the likely value of these, please? |
30th Oct 2018, 12:40 am | #6 |
No Longer a Member
Join Date: Oct 2016
Location: Maroochydore, Queensland, Australia.
Posts: 2,679
|
Re: Ferranti Audio Frequency Transformers
Due to the fact they have a limited frequency response and are little use for any HiFi "Audiophile" application the prices are still sensible and probably below 20 or 30GBP depending on condition. I have experimented with a number of these transformers and they are ideal for AM radio use and under the right circumstances, the interstage and output transformers are capable of a fairly flat response from around 100Hz to 8 or 10KHz. Typically they were used in 1920's era TRF radios and in that era, many of the speaker systems could barely do a few hundred Hz to 5kHz.
|
14th Nov 2018, 10:49 pm | #7 |
Dekatron
Join Date: Jan 2004
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 8,195
|
Re: Ferranti Audio Frequency Transformers
Hi Phil, nice to meet you art Golborne and I trust you had a good day.
Further thoughts on your transformers, there was a thread on the forum about modulating CRT's with a transformer isolated signal. Your transformers may well work for this purpose and should have a good bandwidth for this application. Ed |