40 lines
2.1 KiB
Plaintext
40 lines
2.1 KiB
Plaintext
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BUG DETECTION ON HOME PHONES
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FIRST OF ALL TO TEST FOR BUGS, YOU NEED A VOM (MULTIMETER) THE HIGHER THE
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IMPEDANCE THE BETTER (A DIGITAL WITH FET CIRCUITRY OR A VACUUM TUBE VOLT METER
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IS THE BEST).
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FIRST DISCONNECT THE PHONE LINE(S) AT BOTH ENDS. UNDO THE PHONE INSTRUMENT
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AND HOOK IT UP TO THE ENTRY POINT OF THE PHONE LINE FROM THE OUTSIDE WORLD (MA
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BELL DOES NOT LIKE YOU CUT HER OFF COMPLETELY.) THE SCHEME IS THE PHYSICALLY
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ISOLATE YOUR HOUSE, APARTMENT, ETC. FROM THE OUTSIDE WORLD. BUT BEFORE YOU DO
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THIS MEASURE THE LINE VOLTAGE (IT SHOULD BE APPROXIMATELY 48 VOLTS).
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NOW WITH THE WIRES DISCONNECTED AT BOTH ENDS, SET YOUR RESISTANCE SCALE TO A
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HIGH READING AND MEASURE THE RESISTANCE OF THE PHONE LINE, IT SHOULD BE VERY
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HIGH ON THE ORDER OF MILLION OHMS OR MORE, THIS IS THE NORMAL CONDITION, SINCE
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YOU ARE MEASURING THE RESISTANCE OF AN OPEN CIRCUIT. IF IT IS MUCH LESS, SAY
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50-100KOHMS THEN YOU A DEVICE ON THE LINE THAT DOES NOT BELONG THERE, PROBABLY
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A PARALLEL BUG.
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NOW TWIST THE END OF THE DISCONNECTED WIRE AND GO TO THE OTHER END AND
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MEASURE THE RESISTANCE OF THIS. THIS RESISTANCE SHOULD BE ABOUT ONE OHM OR
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TWO AT THE MOST IN A BIG HOUSE WITH A LOT OF PHONES. IF IT IS MORE, THEN YOU
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PROBABLY HAVE A SERIES BUG.
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IF IN THE FIRST CASE, TAKING PARALLEL MEASUREMENTS USING A METER (NOT
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LEDLLCD) AND YOU NOTICE A "KICK" IN THE NEEDLE, YOU PROBABLY HAVE A LINE TAP.
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NOW IF YOU ALSO MAKE A MEASUREMENT WITH THE WIRE END TWISTED TOGETHER AND
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YOU NOTICE THE RESISTANCE READS ABOUT 1-2KOHMS, THEN YOU MAY HAVE A DROP-OUT
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RELAY. A DROP-OUT RELAY IS A RELAY THAT SENSES A PHONE GOING OFF HOOK, AND
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SIGNALS A TAPE RECORDER TO START RECORDING.
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ANOTHER TEST TO DO WITH THE PHONES STILL HOOKED UP TO THE OUTSIDE WORLD, ON
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HOOK VOLTAGE IS ABOUT 48 VOLTS AND OFF HOOK IS ABOUT 6-10 VOLTS. ANY OTHER
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CONDITIONS MAY MEAN TELEPHONE SURVEILLANCE.
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IF YOU USE A WIDE RANGE AUDIO FREQUENCY GENERATOR AND CALL YOUR HOUSE,
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APARTMENT, ETC. FROM ANOTHER PHONE AND SWEEP UP AND DOWN THE SPECTRUM, AND YOU
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NOTICE THE PHONE ANSWERS ITSELF SOMEWHERE IN THE SWEEP YOU PROBABLY HAVE AN
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INFINITY TRANSMITTER ON YOUR LINE.
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