I have one here which is simply a box which you can either hook onto a screw
or use double sided tape, with a push button as described by others
previously.
On the back of the unit is a button which you press to choose your ring tone
of which there are 100.
Rudolph the red nosed reindeer, Brahms lullaby, cuckoo (currently selected),
battle song of the republic, various Christmas carols, green sleeves (of
course) etc.
In view of the options, my guess is that it originated in the U.S.

ATB

David W Wood 
-----Original Message-----
From: For blind ham radio operators [mailto:[log in to unmask]]
On Behalf Of John Miller
Sent: Saturday, February 09, 2013 7:29 AM
To: [log in to unmask]
Subject: Re: door chimes? doorbell?

The ones I had at the apartment had jumpers to set the frequency, tone, song

it played when it rang. With that land lord, I'm sure they weren't expensive

either. Too bad everyone wrecked them, knocked the buttons off and smashed 
them and what not. It ended up a waste of money but if someone ever closed 
the outside doors to the building, which would be a miracle in itself, when 
I lived there, I'd need the door bell because I'd never hear anyone knocking

at the downstairs door or see who it was. I'm glad to be out of that 
building, I liked the area but not the people in that building.
----- Original Message ----- 
From: "Colin McDonald" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Friday, February 08, 2013 11:02 PM
Subject: Re: door chimes? doorbell?


> the one I used for years had I think 6 frequencies controlled by jumpers 
> in
> the button and receiver.
> Just like garage door openers have at least 6, usually more jumpers or dip
> switches to control their frequencies so as to minimize problems with
> spectrum usage.
>
> You can probably buy 2.4 GHZ units with auto frequency adjustment and or
> digital signal instead of analogue FM and get even more security if you
> will.
>
> 73
> Colin, V A6BKX