Maxon SP-1102, Руководство по обслуживанию, Страница: 13 / 35

Service Manual SP - 1402
Page 13 of 35
Transmitter Performance Tests
Power Output
a) Connect the transmitter to the Communications Test Set (CTS) with the power meter set
to read 5W for the SP-1402
b) Set the power supply to 7.5Vdc and connect a dc voltmeter across the power supply to
monitor the supply voltage.
c) Set the CTS to the same frequency as the radio and then set the PTT to start
transmitting. Check and record the power output. The nominal power output is 5W
d) Reduce the power supply voltage to 6.6Vdc and then set the PTT to start transmitting.
The output power should be greater than 65% of the level measured above.
Frequency Error
a) Using the frequency counter check that the transmit frequency is /- 750Hz of the
frequency which is programmed into the radio.
Distortion and Deviation Measurements
a) Set the radio to the middle TX frequency. Connect the oscilloscope to the AF output of
the modulation meter.
b) Set the audio signal generator to 1 kHz tone, low output impedance and adjusts its level
for 60% system deviation:
12.5 kHz channel spacing 1.5kHz dev
25 kHz channel spacing 3kHz dev
c) Press and hold the PTT button.
d) Measure the audio distortion. This should be less than 5%.
e) Increase the audio signal generator level by 20dB (10x voltage). The peak deviation
should be:
12.5 kHz channel spacing <= 2.0 kHz dev
25 kHz channel spacing <= 3.5 kHz dev