[mountainlion]

You can get cheap hand held 2 way radios in CB and low power models. You can use two handsets form a rotary dial telephone some wire and have a secure phone system.

Two cans and a string.

[Bogey78O]

The tech behind wired voice telecom is essentially over 100 years old. Everything since is just ways to aggregate the links.

Yea, if you have 2 handsets, you can wire two lantern batteries together in series and have a private line. Throw in a few dollars in transistors, transformers, and circuitry and you can even make it ring on the other end when you pick up the handset.

If ever society collapses a bit of work can turn a dead phone system into a neighborhood alert network.