XPost: sci.electronics.repair   
   From: rherber1@bigpond.net.au   
      
   On Tue, 31 Jul 2007 20:37:13 GMT, Joy  wrote:   
      
   >Does anyone know where I could buy a cheap DTMF tone generator?   
   >I think that's what they are called. They used to be used to enter   
   touch   
   >tone phone sounds into the receivers of dial pay phones so you could   
   >access your answering machine.   
   >   
   >I know someone who only has rotary phones (she claims they are the   
   only   
   >ones that work with her hearing aids) and is moving to a place where   
   the   
   >main door can be remotely opened by pressing a key on her phone.   
   Since she   
   >doesn't have a touch tone phone, I thought a portable tone generator   
   might   
   >work.  Radio Shack doesn't carry them and I don't know where else to   
   look.   
   >   
   >Yes, I could always hook up a small, touch tone phone next to her   
   dial   
   >phone but then she couldn't easily move it between phones. Maybe a   
   cheap   
   >cordless phone would work. Those I have.   
   >   
   >Does anyone know where I could get a tiny wired phone? I had once   
   once   
   >(Radio Shack) and it was 2 x 1.5 x .75 inches with a 2.5 mm plug for   
   a   
   >mic/headset just like those used on cordless and wireless phones. It   
   even   
   >had "to line" and "to telephone" jacks.   
   >   
   >Thanks for any leads or even the right search keywords on ebay. I   
   didn't   
   >find any with my searches.   
   >   
   >And sorry if these aren't appropriate newsgroups. I thought people   
   here   
   >would know about this stuff!   
   >   
   >Thanks!  Joy   
      
   I am guessing that your friend uses an analogue hearing aid. If this   
   is so and it is a behind the ear type then it should have a switch on   
   it with a 'T' position (Telephone). The switch should be in this   
   position when she is making or receiving calls. The older rotary dial   
   phones probably have a more powerful magnetic circuit in the receiver   
   and that is why these work and the dtmf types which she has tried   
   don't.   
      
   The problem can be quite easily be rectified by purchasing a dtmf   
   phone which is hearing aid compatible. These types have an additional   
   inductive loop coil inbuilt to provide a suitable signal level for   
   pick up by the hearing aid when it is switched in the 'T' position.   
   http://telephones.att.com/telephones_ui/phone_store/dsp_product.   
   fm?itemID=1428&parent=20017   
      
   At $15 I doubt you could do it much cheaper and you won't have an   
   extra piece of junk hanging around just to provide dtmf.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)