Codan Radio Communications VT-3-150-SN 用户手册
Audio Processor Board Instruction Manual
9-9
10
Apply a 1 kHz, -8 dBm input signal, the modulation should be 90%, observe that the
distortion of the transmitted signal is within 5.0%.
distortion of the transmitted signal is within 5.0%.
11
Slowly increase the input audio signal level to 5 dBm and observe that the modulation
does not go over 100%. This step verifies the correct operation of the ALC .
does not go over 100%. This step verifies the correct operation of the ALC .
12
Change 13.8Vdc power supply to 10V and then to 17V, the modulation of the output RF
signal should remain at the same level of 90% ±7% and distortion should be less then
3%. This step verifies the correct operation of the power regulator on the transmitter
amplifier board.
signal should remain at the same level of 90% ±7% and distortion should be less then
3%. This step verifies the correct operation of the power regulator on the transmitter
amplifier board.
13
Repeat steps 7 and 9 if required.
14
Supply a 1 kHz, -10 dBm signal to the microphone input. (Note the level restriction of -
25 dBm to 0 dBm.)
25 dBm to 0 dBm.)
15
Adjust the Microphone Input Level Adjust pot (R1) to achieve 50% of RF signal
modulation. Observe that the distortion should be under 5%.
modulation. Observe that the distortion should be under 5%.
16
Turn off the transmitter. Remove the signal source and replace all the screws.