SG-2000 MANUAL
190
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23.3.10
Speaker Clipping Level Check
Connect the scope probe to the SPKR resistor and change to 2 volts/div.
With volume set at maximum, increase the audio generator output level until
clipping is visible on the scope. Record the results.
Audio in
= 0.12 VRMS to 0.19 VRMS
SPKR
= 10 Vpp to 12.0 Vpp
Verify that no spikes are generated on the scope while adjusting the volume up
and down.
Turn off the radio and power supply. Disconnect the Display RX Audio Test
Fixture.
Transmit Tests
23.3.11
Microphone
Enabling Test
Connect the microphone and speaker cables from the test head to J4 and J5
respectively.
Turn on the power supply and then the radio. Set the radio to the base station
frequency in A3J mode.
Connect the Microphone PTT Toggle Switch to the microphone input on the
test head. Ensure the switch is off. Connect the audio generator to the
Microphone PTT Toggle Switch.
Set Audio Generator for.
Load
= External
Frequency = 1 KHz
Amplitude = 30 mVRMS (measure with voltmeter)
With J6 in the DYN configuration, adjust the volume to the maximum. Listen
for the 1 KHz tone from the generator on the speaker. If any tone can be heard,
check Q3; it could be defective.