Intercom landline phone network?

Hi, me and my friends would like to get an answer of how we could make an intern network with tree or more landline phones.

http://www.epanorama.net/documents/telecom/telephone_intercom.html
framistan6 years ago
If you connect any 2 landline phones to each other, with a 9volt battery in SERIES with them..... you can talk to each other on the 2 phones. Just run a long wire pair from one phone to the other phone. If you add one more wire... you can add a buzzer line that will ring a buzzer to tell the other person to answer the phone. Unfortunately, to use the existing "ringing" function of a phone requires about 85 volts AC to make it ring. so you are better off just making your own "ringer" This would probably work using a very long wire between the 2 handsets.... maybe a quarter mile??? if longer distance is needed, you might need to add a couple more 9 volt batteries. I think it would also work with more phones... but volume might get low if too many people were on line at the same time.