you can purchase a dtmf dialler keypad for around £10 (or less) shop around for one. Ebay sellers have them listed and you can get one from maplins (www.maplins.co.uk)
The unit is like a small keypad with 0 to 9 and * and # and the unit generates a tone every time you hit the respective button.
If the older phone has room in the base then it may well be possible to modify the dtmf dialler and incorporate it into the phone. This depends on a few things though such as how much internal space you have in the phone and of course how big the dtmf dialler unit is !
Also, if you have had the phone recently just make sure that there is no T--P switch and beware that some of the older phones can switch to tone by pressing the # button when you first pick up to dial.
regards,
tim@pcdgroup.fsnet.co.uk
tim
July 2007
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix corded phones.