Path: utzoo!attcan!uunet!lll-winken!lll-tis!ames!think!eplunix!raoul
From: raoul@eplunix.UUCP (Ignacio Nico Garcia)
Newsgroups: sci.electronics
Subject: Pulse Dialing
Message-ID: <435@eplunix.UUCP>
Date: 24 Jun 88 14:07:01 GMT
Organization: Eaton-Peabody Lab, Boston, MA
Lines: 26


	There is some question as to just how tough it is to
build a phone, or a phone system on your own. If I had 50 
research engineers and the resources of a multi-national company
like Western Union ( I *think* they bought the first patent rights),
it wouldn't take very long at all. There are even lots of 
published circuits today that do the job. What is amazing is that
they built the first system with only resistors, capacitors, relays,
and transformers. No diodes. No transistors. No IC's whatsoever.
The damn things are so durable you can crack nuts with the old ones.

	In terms of building a system for one's own house, I worked
out the circuits for a system at my student living group. I had 
designs that included intercom, PA, a phone line that was always
on the ringing line, and all the bells and whistles I could think of.
Then I thought of the reliability and maintainability of a home-built
customized system and just upgraded our phone service instead. 

	Essentially, home or custom designers can do weird things 
to their circuits and get away with it. The phone company, however,
had to pay for all repairs and complaints with their own time and
money, and could save lots of money by manufacturing lots of unkillable
units instead of marginally cheaper but unreliable widgets. Look at the
phones on the market now. The solidest ones are the old Ma Bell models
that Ma Bell had the service contracts for. Who says monopolies are
always bad things?

					nico