Posted February 1997

With the proliferation of electronic equipment attached to telephone lines these days, the value of a truly simplistic device called a teleprotector can easily be overlooked. Today’s modern office has a fax machine, credit card authorization dialer, fax modem/software on their main computer (INFOFAX), fax modem/software on their Windows ’95 PC/Workstation, and now even a modem for Internet access, and sometimes all sharing the same telephone line!

Since the total traffic from all these devices falls way short being full time, they can get away with this trickery so long as the devices are considerate of one another, and don’t attempt to use the line at the same time.

But how? Most electronic equipment is just too dumb to check to make sure no other device is using the line first before interrupting anddialing. It just picks up, and starts punching buttons. And of course, this rude behavior will most likely interrupt the other devices bringing everything to a crashing halt.

Enter the Teleprotector. This simple device from Radio Shack (about $20) listens to the line on behalf of the device its serving, and only allows access to the line if a dial tone is present. Therefore it won’t permit its rude user from interrupting another device. If ALL devices that are sharing the line have one of these polite traffic cops, no one would ever interrupt another!

Plugging in these devices can be less than intuitive. Take a look at the diagram, and notice that they all are connected to the incoming telephone jack in PARALLEL, not in series. That keeps all the teleprotectors on the same level with each other.