DE
DANIELS
ELECTRONICS
3-6
MT-3 AM Transmitter Main Board Instruction Manual
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 .
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%. If not, adjust the pot R4 on the Audio Processor Board to achieve this.
This step verifies the correct operation of the AMC.
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.)
15)
Adjust the Microphone Input Level Adjust pot (R1) to achieve 50% of RF signal
modulation. Observe that the distortion should be under 5%.
16)
Turn off the transmitter. Remove the signal source and replace all the screws.
