Sekotech ST-300 SPIDER, Руководство по эксплуатации, Страница: 45 / 68

OPERATING MANUAL
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Launch automatic scanning (“F4” button). The device will be consecutively testing all the two-wire
combinations, pausing for a few seconds at each pair, so the user can analyze the sound output. The
two-wire combination currently tested will be highlighted by table cursor.
Having run the full cycle, scanning will stop.
If the test sound can be heard during the scanning cycle, it means that a dynamic microphone
is attached to the pair of wires tested at that point. When the scanning cycle is complete,
select the corresponding table line with the arrow keys to listen to the signal again. For a more
detailed analysis, press “MODE” to go to the main screen of the LFA mode. The signal can then
be studied in the oscilloscope mode or spectrum analyzer mode. The wire pair selection made in
the automatic mode will be retained.
If the testing table shows voltage beyond -3V/+3V on any pair(s), and the test sound could be
heard in the headphones as the cycle ran through the pair(s) in question, that is a likely sign of
active electret microphone(s) attached to the pair(s).
If the testing table shows voltages in excess of 3V on any pair(s), but the testing sound has not
been heard in the headphones, one should look for causes of such abnormal voltage.
If the test sound could not be heard in the headphones at any point during the scanning cycle, it
is unlikely that a dynamic microphone is connected to the line. The line should be further tested
for electret microphones by applying a bias voltage and then reversing it.
Enable gain control (“F2” button) and set minimum gain (0dB) with the key.
Disable gain control (“F2” button).
Enable bias voltage control (“F3” button).
With the key set bias voltage to +14V.
Disable bias voltage control (“F3” button).
Launch automatic scanning (“F4” button). The device will be consecutively testing all the two-wires
combinations, pausing for a few seconds at each pair, so the user can analyze the sound output. Having
run the full cycle, scanning will stop.
If the test sound can be heard during the scanning cycle, it means that a electret microphone
is attached to the pair of wires tested at that point. When the scanning cycle is complete,
select the corresponding table line with the arrow keys to listen to the signal again. For a more
detailed analysis, press “MODE” to go to the main screen of the LFA mode. The signal can then
be studied in the oscilloscope mode or spectrum analyzer mode. The wire pair selection made in
the automatic mode will be retained.
If the test sound could not be heard in the headphones at any point during the scanning cycle,
scanning should be repeated with a reverse bias voltage.
Enable bias voltage control (“F3” button).
Press the key to reverse the bias (change polarity).
Disable bias voltage control (“F3” button).
Launch automatic scanning (“F4” button). The device will be consecutively testing all the two-wire
combinations, pausing for a few seconds at each pair, so the user can analyze the sound output. Having
run the full cycle, scanning will stop.
If the test sound can be heard during the scanning cycle, it means that a electret microphone
is attached to the pair of wires tested at that point. When the scanning cycle is complete,
select the corresponding table line with the arrow keys to listen to the signal again. For a more
detailed analysis, press “MODE” to go to the main screen of the LFA mode. The signal can then
be studied in the oscilloscope mode or spectrum analyzer mode. The wire pair selection made in
the automatic mode will be retained.
If the test sound could not be heard in the headphones at any point during the scanning cycle,
it is unlikely that an electret microphone is connected to the line.