2026-2027
Expert-Verified Questions and Answers
(With A+ Grades Guarantee)
,What are the correct VHF Channels and Frequencies for Ch-16, 156.800 MHz, Ch-70, 156.525 MHz and Ch-13, 156.650 MHz.
Calling/Distress, DSC and bridge-to-bridge operations?
What is the frequency separation between Transmit and 4.6 MHz
Receive frequencies on a duplex channel?
What is the assigned channel spacing for VHF channels? 25 kHz
What is the allowed frequency tolerance for the DSC 10 ppm
carrier frequencies?
Using a frequency counter with an accuracy of 2 ppm, 156,798.758 kHz and 156.526.243 kHz.
which of the following are within legal tolerance for the
frequencies of 156.800 MHz and 156.525 MHz?
Using a frequency counter with an accuracy of 5 ppm, 156,875.774 kHz and 157.199.321 kHz.
which of the following are within legal tolerance for the
frequencies of 156.875 MHz and 157.200?
What is the purpose of the USA-INT switch? To change from duplex to simplex operation on designated channels in U.S. waters.
What may happen if the USA-INT control is left on INT Your signals will be heard but other station replies will not be heard on certain
when in U.S. waters? channels.
What is the purpose of the Dual Watch function? To rapidly switch the radio's receiver between two channels.
What is the proper adjustment of the squelch control for Just below the point where the noise breaks through.
maximum sensitivity?
Which of the following transmitter power levels are Low Power: 1 W, High Power: 25 W
permitted by FCC rules?
Which of the following controls is not found on a VHF-DSC R.I.T.
transceiver?
Which of the following best describes the Capture effect? The receiver will reject all but the strongest signal.
What may be adjusted in a FM ratio detector for improved Ratio Arm balance control bridge
signal-to-noise?
What is the function of a properly adjusted limiter circuit? Maintains a constant output amplitude with a varying input amplitude.
, How is SINAD defined? SINAD is the sum of the signal, noise and distortion divided by the sum of the noise
and distortion.
What would be considered a normal sensitivity for 10 db of 1 microvolt
quieting in a VHF marine receiver?
What is meant by full quieting in a FM VHF receiver? The received signal is strong enough to completely quiet the receiver background
noise.
What condition may prevent a VHF radio receiver from The output signal of the Phase Locked Loop (PLL) circuit in the frequency
staying tuned to the desired channel? synthesizer has become unlocked.
What fault may exist if a VHF radio receiver fails to The AF amplifier may be defective or the transmitter Push-To-Talk circuit may be
produce audible output from the speaker and the squelch activated.
control has no effect?
What is indicated if a VHF radio fails to receive nearby A crowbar circuit has prevented an over current condition that might damage the
stations and a voltmeter connected between the positive radio.
side of a radio's DC line and ground reads zero line
voltage, and the fuse reads zero on an ohmmeter?
What condition may prevent a VHF radio receiver from The weak RF signal has been suppressed at the limiter stage of the receiver by
receiving a weak signal? capture effect.
What is the best test procedure to isolate the source of Use an oscilloscope to visually display AC signals on the output of each AF amplifier
distortion in the audio output of a receiver? stage.
What condition may cause a significant loss in VHF A reading of 9.6 when a voltmeter is connected between the positive side of the
receiver sensitivity? radio's DC line and ground.
Which test procedure may be used to determine a VHF Set a signal generator to the frequency of the VHF receiver, adjust the output signal
receiver's minimum discernible signal? to near zero, and increase the signal level until an audio voltmeter connected to the
AF output point indicates a 3-dB increase.
Which procedure may be used in many U.S. ports as a Tune the VHF radio to 162.550 MHz, 162.400 MHz or 162.475 MHz and listen for
quick field test to determine if a shipboard VHF receiver is broadcasts from the National Oceanic and Atmospheric Administration.
operating properly?
What ohmmeter reading may indicate a faulty component A transistor indicates low resistance between emitter and base when test leads are
in a VHF receiver? reversed across them.
What condition may indicate a VHF receiver fault? The same voltage reading between each lead of a 100K-ohm resistor and ground in
a bias circuit.
What condition may cause noisy operation of a VHF A defective potentiometer in the audio frequency amplifier stage.
receiver?
What is the maximum allowable deviation of a marine VHF 5 kHz
transmitter?