Staying Within the Lines

BK Precision's new Model 201 Telephone Line Checker is a low-cost, compact, lightweight, portable device that can be used to check phone lines. It quickly checks whether a phone line is digital or analog before the modem is connected, thereby protecting the modem from damage. By simply inserting the phone line to the receptacle on the Model 201, or by plugging it into the wall jack with the supplied adapter, the unit identifies if the line is safe, if it has polarity reversal, or if the line is open.

When near a radio transmitter telephone, phone wires can act as antennas that draw radio frequency interference (RFI) to corrupt data received over a modem. This can interrupt Internet, fax and e-mail connections. The Model 201 incorporates a line noise filter to counteract RFI, protecting the modem on the computer. The line checker weighs only 1 oz and measures 2.8" x 1.2" x 1", and comes complete with an adapter cable. BK Precision, Placentia, CA, (714) 237-9220,

This article originally appeared in the 06/01/2000 issue of THE Journal.