4
is the same as that of “QT(670) frequency offset”.
3.8 Receiving Sensitivity
Double-click to enter “Receiving Sensitivity” in “Interphone Performance Tuning” Mode to adjust the five
frequency points including ”Lowest”, “Low”, “Mid”, “High” and “Highest” respectively and the number from
0 to 255 for setting max sensitivity of all points.
3.9 Receiver Squelch setting
Double-click to enter “SQL9 open” in “Interphone Performance Tuning” Mode and click “Broadband” to
make the frequency of the transmitting signal corresponding to the receiving frequency (level of -116dBm,
modulation signal of 1kHz and frequency offset of 3kHz) showed at each frequency point of the software.
Enter all points including ”Lowest”, “Low”, “Mid”, “High” and “Highest” respectively for automatic
adjustment of software and then press next point after no big change to numbers. After that, adjust
“Narrowband”, the debugging method is the same as that of “Broadband” except the input modulation
signal is changed to frequency of 1kHz and frequency offset of 1.5kHz.
Select “SQL9 open” in “Interphone Performance Tuning” Mode and click “Broadband” to make the
frequency of the transmitting signal corresponding to the receiving frequency (level of -118dBm,
modulation signal of 1kHz and frequency offset of 3kHz) showed at each frequency point of the software.
Enter all points including ”Lowest”, “Low”, “Mid”, “High” and “Highest” respectively for automatic
adjustment of software and then press next point after no big change to numbers. After that, adjust
“Narrowband”, the debugging method is the same as that of “Broadband” except the input modulation
signal is changed to frequency of 1kHz and frequency offset of 1.5kHz.
Select “SQL1 open” and “SQL1 close” respectively in “Interphone Performance Tuning” Mode, and
adjust by the same method except the open level of transmitting signal changed to 123dBm and the
close level to 125dBm.
4 Receiving Low-voltage Alarm
Adjust power voltage to 5.8V and double-click to enter “Receiving Low Voltage” in “Interphone
Performance Tuning” Mode for automatic detection of the software, and then click “Save” for exit after no
or little variation in numbers.
5 Adjusting explanation
Table 3 Voltage controlled oscillator
Item Test condition Instrumentation Test point Correcting
member Requirement Remarks
Setting Supply voltage battery
terminal:7.4V DMM CV
CH: Receiving low
frequency point TC2 1.0V±0.2V Adjustment
Locking
voltage
CH: Transmitting high
frequency point ≤4.0V Observation
