I mentioned negative comments because some of the negative feedback is positive in a technical nature. It is not meant to be directed against an individual personally, but generally against a method or procedure that others feel is opposed to what is generally accepted as the correct way of doing things (But always remember, the accepted way may not be the correct way).
If, at any time I let the wrong things through, please point it out to me so I can hopefully prevent it happening in the future.
Tim Johnson
My question: Is there a tracking device available that would allow
me covertly to locate the computer after it is stolen. I know there is
software that sends a signal when the thief uses the dial out modem. My
concern is that these people are cleaning the files out and selling
these laptops at the swap shop for easy money. They may never use the
modem. Also it would be a nightmare to have a security guard check each
person at the door because of the large amount who take their laptops
with them each night. Any thoughts?
This one was an older phone with the ringer removed or disconnected OR a newer phone with a "ringer equivalency" of about .03 (maybe a piezoelectric "chirper") that "borrowed" power from the phone company. The off-hook voltage is about right for an older phone, though (depending on distance to the C.O.).
>The other phone line and fax line each had apprioximately 40 vdc on
hook
>and 7.1vdc off hook.
These two were were drawing current while on hook - could have been
one of several things: defective equipment, an older phone with a "ringer
equivalency" of >1.0, (not the most likely choice since the off hook
voltage is a bit high for an older phone) or a newer phone that
"borrowed" power from the phone company while on hook.
Of course, those are the obvious guesses -
Regards,
Mike Andrews
Moral of the story. Its not just residential clients who are sometimes
schizophrenic. Sometimes their phone lines are too.
Kevin
Second phone line and fax line from a different C.O?
Were they going through a fax switch or some other common device with a P-N switching junction in it? Toll restrictors or some other SOHO gadget? Modem isolators on each line? The off hook difference in voltage is approx that of the drop across a P-N junction (diode or transistor).
One line on copper back to the C.O. and another on fiber? I measured some difference between lines here at the office when they started switching over to fiber. They did the further C.O. first on one bank of lines. Don't remember the voltage differences but they caught my eye at the time. Now there's fiber to within a mile of the building.
Leaky/failing lightning or surge protectors on those two C.O. lines? Possible for one set of lines to take a hit and not the other if they are going to different C.O.'s. Damaged protectors on the phone lines can cause all sorts of freaky readings, and all bets are off. Top quality surge protectors will fail in the shorted mode forcing you to troubleshoot and replace them. Cheaper ones will fail as leaky across the pair or one side or the other to ground. Usually if they fail one side leaking to ground that will induce hum on the line and be very obvious as an unbalanced line.
Please advise the group in the interest of edification.
Regards ....... Steve