Path: utzoo!utgpu!news-server.csri.toronto.edu!clyde.concordia.ca!uunet!wuarchive!mit-eddie!bbn.com!grossman
From: grossman@bbn.com (Martin Grossman)
Newsgroups: sci.electronics
Subject: Phone hookups
Keywords: phone, telco
Message-ID: <58953@bbn.BBN.COM>
Date: 16 Aug 90 11:41:41 GMT
Sender: news@bbn.com
Lines: 40



I would like to setup a mini phone service at my home connecting just 2 or 3
(maybe 4) phones.  What do I need to buy (radio shack) to do this.


--------                        --------
|phone |------------------------|phone |
|      |------------------------|      |
--------                        --------
|ringer|                        |ringer|
--------                        --------

MISC INFO:

	1) There will be no connections to any regular telco phone lines.
	2) The little box's above marked ringer should be small and right next
	   to the phone(s).  They should just have 1 button each and ring the
	   other phone(s) when depressed.
	3) The box's marked phone should be any phone that can be hooked upto
	   the standard (US) phone system.
	4) I understand just a little about how phones work...
	   a) I think its 50-60VAC at 20-30HZ to ring a phone
	   b) phone looks like inf resistance/reactance when on hook
	   c) phone looks like approx 680 ohms when off hook
	   d) there's a small DC voltage when off hook
	5) The dial (or push buttons) won't be used (ie just the ringer box)
	6) This will be used instead of multiple walky-talkies.

USE:
	1) One phone will be in the basment and the other 1 or two will be
	   upstairs.  I want to be able to signal (via the ringer) and talk
	   without running upstairs or shouting. Besides...its a great project.

QUESTIONS:
	1) how do I connect tip and ring from each phone
	2) what do I need between the phones to act as the phone co.
	3) what do I use for the rigner box
	4) what do I need to add if I want to hookup a third phone or forth.
	   PS in now way am I trying to compeat agianst MA-BELL.