| |
G4EBT > RADIO 11.11.07 22:05l 68 Lines 2332 Bytes #999 (0) @ WW
BID : DC7029G4EBT
Read: GUEST DK5SG
Subj: Re: 2 Transistor radio
Path: DB0FHN<DB0RGB<DB0MRW<OK0PPL<DB0RES<DK0WUE<CE8FGC<ON0BEL<GB7FCR
Sent: 071111/1945Z @:GB7FCR.#16.GBR.EU #:50706 [Blackpool] FBB-7.03a $:DC7029G4
From: G4EBT@GB7FCR.#16.GBR.EU
To : RADIO@WW
Dave, G0OEK wrote:-
>I wonder if anyone has a circuit for a 2 transistor, loudspeaker
>MW receiver. Using a ferrite rod antenna.
> I did have one years ago, (Shop bought), and I think
> it received about 6 or so stations. I would like to
> build one, and get it working. Just for fun....
> Hope you can help, with a piccy, gif jpg, or ascii.
Many people will have fond recollections of the long since defunct Radio
Constructor magazine, in which for many years, Sir Douglas Hall wrote many
articles based on his ingenious "Spontaflex" circuits.
The designs hark back to the days when transistors were expensive, and his
aim was to squeeze as much performance out of them as he could. He was a
wonderful man who lead a fascinating life and there's a website dedicated
to him and his circuits.
http://freespace.virgin.net/spontaflex.reflex/
There you will find all the Radio Constructor magazines by Sir Douglas
spanning the period 1953 - 1978 to download, and an article on his
biography. Also, articles from Practical Wireless and Radio Bygones.
There is also a list of UK suppliers of most of the components for these
old circuits. A "one man band" that I've used extensively is Pete Roberts,
at:
You can view or download his catalogue at:
http://hometown.aol.co.uk/oldradioparts/front.htm
His website states that he's shortly going to make up kits of parts for
the Spontaflex circuits as they have quite a following.
You'll see countless old transistors radios at car boot sales from which
ferrite rod aerials, speakers, transformers, diodes, transistors can be
stripped.
Incidentally, if you come across a "dead" radio using AF116/117 germanium
transistors, they suffer from "whiskers" growing from the crystalline
germanium which short to the screen lead.
Sometimes you can bring the radio back to life by snipping the screen
lead with no detrimental effects. It's no use using any "new old stock"
AF116/117 replacements as they to will by now have grown whiskers.
If you can find any, use AF125s to replace AF116/AF117 transistors.
Best wishes
David, G4EBT @ GB7FCR
British Vintage Wireless Society Member
G-QRP Club Member, No: 1339
Cottingham, East Yorkshire.
Message timed: 18:44 on 2007-Nov-11
Message sent using WinPack-Telnet V6.70
(Registered).
Read previous mail | Read next mail
| |
