|
Homebrew Equipment A place to show, design and discuss the weird and wonderful electronic creations from the hands of individual members. |
|
Thread Tools |
24th Feb 2014, 5:29 pm | #1 |
Octode
Join Date: Jun 2005
Location: Sheffield, South Yorkshire, UK.
Posts: 1,227
|
Crazy idea? Phone to radio.
Is it possible to convert an oldish telephone into a simple radio? I was thinking of fitting a simple crystals etc type front end and feeding into a phone. Could it possibly work?
|
25th Feb 2014, 11:21 pm | #2 |
Dekatron
Join Date: Feb 2007
Location: Leominster, Herefordshire, UK.
Posts: 16,536
|
Re: Crazy idea? Phone to radio.
Yes, but no better than a crystal set is inherently capable of doing (which by and large is pretty disappointing unless a lot of effort is put into optimizing every last detail). The earpiece of the phone would probably need a matching transformer to get the best out of the crystal set's output. Some research into what crystal set enthusiasts are doing to optimize performance would probably help decide what circuit to use. Presumably the dial could be used to operate a tuning capacitor or gang, but the size and hence quality factor of the coil(s) would be limited by space constraints.
Best results would probably be obtained if the phone line into the house were overhead wire as it should be possible to use this as a long wire aerial using a suitable low value coupling capacitor to isolate the dc and phone signals from the set. This may not be viable if ADSL figures on the line in question. Of course it wouldn't exactly be approved for connection to the line either. It could be set up for minor amusement- pick up the phone and get an earful of 5-live or some such. Not too different from real cases of long overhead lines and dodgy joints near Droitwich providing a blast of the Light Programme when least expected, really.
__________________
....__________ ....|____||__|__\_____ .=.| _---\__|__|_---_|. .........O..Chris....O |
26th Feb 2014, 10:04 am | #3 |
Heptode
Join Date: Aug 2013
Location: Bradford, West Yorkshire, UK.
Posts: 888
|
Re: Crazy idea? Phone to radio.
Where would the world be if we dismissed our 'crazy ideas'? Build one! Could be a fun project, especially if you have kids and want to get them involved in something different.
|
26th Feb 2014, 12:12 pm | #4 |
Dekatron
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 14,007
|
Re: Crazy idea? Phone to radio.
A bed&breakfast I would visit occasionally in Edinburgh had, as a talking-point, a 1920s-style wall-mounted phone (the type with the receiver on a cord and the microphone hinged out of the wall-mounted unit) whose non-functional insides had been replaced by a simple AM/FM radio.
The owner had pre-tuned it to Radio Scotland rather than trying to work out how to interface the mechanics of the dial to the radio's tuning presets. A micro-switch on the receiver hanger turned it on and off. |
8th Jul 2014, 5:01 pm | #5 | |
Pentode
Join Date: Jul 2014
Location: Bangalore, India
Posts: 132
|
Re: Crazy idea? Phone to radio.
Quote:
My crystal radio works as well with an old telephone handset as with its balanced armature headphones. https://www.vintage-radio.net/forum/...d.php?t=107520 You should try it too! |
|