[comp.dcom.modems] Lightning effects

jtchew@csa3.lbl.gov (JOSEPH T CHEW) (07/09/90)

Lightning can get into your electrical gizmos either by a direct strike on
a line or by a strike NEAR a line (induction).  Either of these effects can
couple through any line, such as power, phone, or antenna.

If you take a direct hit, you're hosed.  Consult something like The Radio
Amateur's Handbook for tips on indirect protection, such as spark gaps and
Metal Oxide Varistor (MOV) surge protectors, and keep your fingers crossed.

Don't consider yourself protected by a commercial "surge protector" power
strip unless you know what's in it.  I understand that the contents and
functions of such things vary widely.

You might also try posting on a ham radio newsgroup.  Those whose hobbies
depend on tall antennas have a whole different perspective on such things.

Finally, you might just try unplugging everything sensitive and expensive
when there's an active lightning storm in the area.  Disruptive but
effective.  I've seen a blue corona around a telephone at night, and heard it
ring, because of a nearby strike.  I've fixed a TV in which the MOVs had been
charred completely off the circuit board, leaving only eight forlorn little
leads sticking up.  I've seen...but I digress.  

Maybe Toby will put in his two cents.  I've seen modems with a little glass
part that looks like it might be a spark gap for the phone line. 

--Joe
JTCHEW@lbl.gov
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"The opinions expressed herein do not necessarily represent intelligence."