Inline DTMF generator

[bukko]

Hi all,

I haven't done any electronics for a very long time. I used to repair home computers years ago (Spectrums, Commodores, etc) but I have no formal training.

I have an old dial telephone on my desk which I really like as I love the retro look, the trouble is my arthritic/rheumatic hands aren't so keen.
I thought a good project would be an inline DTMF box. The phone could plug into the box, the box plugs into the phone socket.
The box could have a hands-free button that takes the phone off the hook, and a keypad like a modern phone which does the DTMF stuff.
After dialling the user can pick up the receiver, switch-off the hands-free and use as normal.

Basically I'm looking for ideas to get this going. I'm not so great with a soldering iron these days but I'll just have to work slower
I've seen some DTMF IC's but I wouldn't know what to do with them.
Also I wouldn't know how to make the hands-free thing work!

Any suggestions of a good place to start?

Thanks all

[David]

Have you wired up your retro phone with a RJ45 plug so that it fits the modern BT sockets? If not, there are wiring diagrams on the internet telling you how to do it.
Having done that, how about experimenting with a line splitter plug (allowing two phones to be connected in parallel across one phone line), and plugging your retro phone into one socket of the splitter, and a modern push button phone into the other? You could initiate the call with the PB phone and carry on with the retro one ...

Hope this helps

[Sock Puppet]

I like David's idea there and your post reminded me of this (still in the junk box).

I hope you can see the image, it's a DTMF dialler which was once allegedly used to get free calls from a payphone when they had pulse dials.

You made your call normally and pressed the DTMF code via the speaker into the handset. The device still bleeps perfectly but I've no idea if it would dial via holding it over a mouthpiece after getting a dialling tone as I don't have a phone fitted to my landline.

I'll try it when I have the chance, it's just food for thought.

[bukko]

Have you wired up your retro phone with a RJ45 plug so that it fits the modern BT sockets? If not, there are wiring diagrams on the internet telling you how to do it.
Having done that, how about experimenting with a line splitter plug (allowing two phones to be connected in parallel across one phone line), and plugging your retro phone into one socket of the splitter, and a modern push button phone into the other? You could initiate the call with the PB phone and carry on with the retro one ...

Hope this helps

Thanks for the suggestion, however this project looks like a good place to start for what I really want:
http://avtanski.net/projects/phone_dialer/