RED PT500-2, Service Manual

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PT500-2 Service Manual
38
Steps for adjustment
：
1)
Enter Computer Test Mode by selecting “Test Mode” in main menu of PT500
Programming Software.
2) Select the items to be adjusted in choice menus, and then adjust the parameters by
function keys on the computer keyboard. 3) Exit Computer Test Mode after adjustment.
7.3 Adjustment
7.3.1 VCO Adjustment
Close “Power-saving Mode”. Set receiving frequency to low frequency point (see Table 7.2)
and in the receiving state, test voltage of PD by DMM and adjust fine-tuning capacitor
TC1/TC2 to get CV voltage of 1.0V±0.2V
Set transmitting frequency to high frequency point (refer to Table 7.2), press PTT and test
voltage of PD by DMM, which shall less than 4.0V
Table 7.2 High/ Intermediate/ Low Frequency Point of All Models
Low Frequency Intermediate High Frequency
Point Frequency Point
Point
PT500-2 400.100 MHz 435.100 MHz 469.975 MHz
7.3.2 Frequency stability
Double-
click to enter “Frequency Stability” in “Test Mode Manual” to achieve the rated
transmitting frequency by adjusting the number from 0 to 255 (Error<100Hz).
7.3.3 RF transmitting power
High power
Adjusts the transmitting power to 3.8-4.2W in the computer (5
frequency points including Highest, High, Med, Low, lowest)
Middle Power
Adjust the transmitting power to 1.8-2.2W in the computer Low Power
Adjust the transmitting power to 0.8-1.2W in the computer
7.3.4 Voice deviation
Maximum voice deviation
Signal source: MOD:1kHz/120mV LPF:15kHz
Adjust the max frequency deviation in the computer adjustment mode. mode.