PT260 Service Manual
13
6.2 Adjustment Items
During the maintenance, the radio’s technique parameters
need to make some necessary test and adjustments after the
components are changed. The following part describes the
adjustment of the circuits.
Some of the parameters can be adjusted (PC mode) by
Kirisun’s program software. These parameters include:
1) Frequency error
2) Transmitting power
3) Low battery warning threshold
4) CTCSS frequency deviation
5) DCS deviation
Steps of the adjustment are as follows:
a. Enter into the PC test mode. The method refers to 4.2.
b. Select “Test mode” in the main menu of the program
software, and enter into PC test mode.
c. Select the items you want to test in the menu, and adjust
the parameters with the keyboard.
d. After finished, exist the test mode.
6.3 Adjustment
6.3.1 PLL frequency adjustment
Select “Frequency Tuning” under the “PC test” mode, click
【Adjustment】, and adjust the value within the range of 0~255 to
make the transmitting frequency equal to the rated value ( The error
is less than 200Hz).
6.3.2 Transmitting power adjustment
Select “High power & low frequency point” under the “PC
test” mode, click【Adjustment】, and adjust the value within the
range of 0~255 to make the transmitting power equal to 4W while
observe the working current, to keep it less than 1.8A.
Adjust “High power & intermediate frequency point” and
“High power & high frequency point” with the method the same as
the above, and the transmitting power of these two situation are all
4W.
6.3.3 Transmitting low voltage warning
Set the voltage of the power supply to 6.8V.
Select “Low voltage threshold” under the “PC test” mode, click
【Adjustment】, and adjust the value within the range of 0~255 to
make Red LED indicator just flash.
6.3.4 Deviation adjustment
Input 120mV, 1000Hz of the audio signal to the MIC jack,
adjust the deviation value to make it to be ±4.0kHz.
6.3.5 DCS transmitting signal waveform and deviation adjustment
Select “Digital sub-audio board band modulation” under the
“PC test” mode, click 【Adjustment】, and observe the demodulated
signal. The waveform should be smooth (near to square wave).
Then adjust the deviation within the range of 0~255 to make it to
be 0.75 ±0.25kHz。
6.3.6 CTCSS deviation adjustment
Select “Sub-audio board band modulation” under the “PC
test” mode, click 【Adjustment】, and adjust the value to make it to
be 0.75kHz ± 0.25 kHz.
6.4 Adjustment Description
The description of the above adjustment, please refer to the
table 6.2 and table 6.3.
To Next Page
Loading...
Need help?
General
