3-L-081: Troubleshooting
3-81L1:
On a 150 watt marine SSB HF transceiver, what would be indicated by a steady output of 75 watts when keying the transmitter on?
There is probably a defect in the system causing the carrier to be transmitted.
One of the sidebands is missing.
Both sidebands are being transmitting.
The operation is normal.
3-81L2:
The tachometer of a building’s elevator circuit experiences interference caused by the radio system nearby. What is a common potential “fix” for the problem?
Add a .01 µF capacitor across the motor/tachometer leads.
Replace the tachometer of the elevator.
Add a 200 µF capacity across the motor/tachometer leads.
Add an isolating resistor in series with the motor leads.
3-81L3:
A common method of programming portable or mobile radios is to use a:
A laptop computer.
Dummy load.
A wattmeter.
A signal generator.
3-81L4:
In a software-defined transceiver, what would be the best way for a technician to make a quick overall evaluation of the radio’s operational condition?
Use the built-in self-test feature.
Set up a spectrum analyzer and service monitor and manually verify the manufacturer’s specifications.
Use another radio on the same frequency to check the transmitter.
Using on-board self-test routines are strictly prohibited by the FCC in commercial transmitters. Amateur Radio is the only service currently authorized to use them.
3-81L5:
How might an installer verify correct GPS sentence to marine DSC VHF radio?
Look for latitude and longitude on the display.
Press and hold the red distress button.
Look for GPS confirmation readout.
Ask for VHF radio check position report.
3-81L6:
What steps must be taken to activate the DSC emergency signaling function on a marine VHF?
Input of registered 9-digit MMSI.
Separate 12 volts to the switch.
Secondary DSC transmit antenna.
GPS position input.
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Color key:
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● = Unseen
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● = Weak
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● = Review
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● = Learned
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● = Incorrect answer
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