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