Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!att!tut.cis.ohio-state.edu!unmvax!bbx!yenta!dt
From: dt@yenta.alb.nm.us (David B. Thomas)
Newsgroups: sci.electronics
Subject: Re: Questions about cordless phones
Message-ID: <1990Dec29.224148.7742@yenta.alb.nm.us>
Date: 29 Dec 90 22:41:48 GMT
References: <52@bootsie.UUCP>
Organization: yenta unix pc, rio rancho, nm
Lines: 27

olson@bootsie.UUCP (Eric Olson) writes:

>1.  About 5 years ago, they started selling "new freqency" phones.
>    What was new, compared to the old phones?

I believe the old cordless phones used to use approximately 27 Mhz and
1700 Khz for duplex operation.  All the newer ones use ~46 Mhz for the
base unit and ~49 Mhz for the handset.

>2.  What frequencies are used by modern ("new frequency") phones?
>    AM or FM?  Sidebands?  Are they all exactly the same frequency,
>    or do some have different or multiple frequencies?

There are ten channel pairs (base, handset).  I'm sure someone will
post the exact frequencies.  I don't have them online just now.
The FM (narrow) mode is used.

>3.  My roommate has an AT&T cordless phone with 3 "channels".  I
>    guessed that they were upper SB, lower SB, and main band.  He
>    claimed they were separate frequencies.  What's the scoop?

You owe your roomie a beer :-)  FM is always used, and the three channels
are actually separate frequencies.

					little david
-- 
This is my .sig.  n?e  .sgurd no gis. ym si sihT