A mismatched antenna system can degrade marine VHF radio performance. Antenna system matching can be analyzed by determining the Standing Wave Ratio (SWR). Which of the following is the best test procedure to determine the VHF antenna system SWR?

Question

A mismatched antenna system can degrade marine VHF ­radio performance. Antenna system matching can be analyzed by determining the Standing Wave Ratio (SWR). Which of the following is the best test procedure to determine the VHF antenna system SWR?

Accepted Answer

Insert a directional wattmeter between the VHF transmitter and the coaxial transmission line connected to the antenna, activate the Push-To-Talk (PTT) circuit, observe the measured values of forward and reflected power.

Answer

Insert a SWR meter between the VHF transmitter and the coaxial transmission line disconnected from the antenna, set the radio to an unused channel, activate the Push-To-Talk circuit, and read the measured value.

Answer

Insert a directional wattmeter between the VHF radio and an artificial antenna, set the radio to any channel, key the microphone, and read the values of forward and reflected power.

Answer

Insert an in-line RF Power meter between the VHF transmitter and the coaxial transmission line connected to a 50 ohm load, activate the Push-To-Talk (PTT) circuit, observe the measured value of reflected power.