GROL General Radiotelephone 5

Question 1

Under FCC Part 80 rules, what is the maximum permissible carrier power for a ship station operating on 2182 kHz?

Accepted Answer

400 watts

Answer

FCC Part 80 limits ship station carrier power on 2182 kHz to 400 watts to prevent excessive interference on the distress frequency.

Question 2

What is the purpose of the Digital Selective Calling (DSC) controller used in GMDSS?

Accepted Answer

To send automated distress and calling signals on designated frequencies

Answer

DSC sends digital bursts containing MMSI, position, and distress nature on designated frequencies, automatically alerting Coast Guard and nearby vessels.

Question 3

What is the decibel gain of an antenna rated at 6 dBd relative to a half-wave dipole?

Accepted Answer

6 dB above a dipole, or about 8.15 dBi above an isotropic radiator

Answer

dBd is gain referenced to a dipole; since a dipole has 2.15 dBi of gain, 6 dBd = 6 + 2.15 = 8.15 dBi above an isotropic radiator.

Question 4

What is the minimum watch requirement for a compulsorily equipped ship station under GMDSS while at sea?

Accepted Answer

Watch on DSC Channel 70 and voice Channel 16 at all times

Answer

GMDSS requires continuous automated DSC watch on Channel 70 (and/or MF/HF DSC) plus continuous voice watch on Channel 16 while underway.

Question 5

Which component in a PLL (Phase-Locked Loop) frequency synthesizer directly determines the output frequency?

Accepted Answer

The voltage-controlled oscillator (VCO)

Answer

The VCO generates the output frequency; the PLL feedback loop locks the VCO to a precise multiple of the stable reference frequency.

(GROL) General Radiotelephone Operator License Practice Test

(GROL) General Radiotelephone Operator License Practice Test

GROL General Radiotelephone 5