gill (10/08/82)
#R:mcnc:-130000:physics:15700003:000:662 physics!gill Sep 2 12:35:00 1982 In fact, there is a small sensitivity to polarity on dial phones. If your phone "dings" when you pick or hang it up, or "dings" repeatedly when you dial, reversing the tip and ring will often help. I have only seen this happen on non-Bell phone systems (e.g. MIT's archaic 617-225 dormline system). The false bell triggering is caused by the kickback from the office's loading coil when the hook or dial breaks the circuit. The reactive pulse tends to be polarized, and most ringer circuits don't clank equally for pulses of either polarity. Hence, by swapping the red and green, you may be able to solve the problem. Gill Pratt ...alice!gill OR gill@mc