Ham Radio Technician Test Equipment & Tools Usage 5

Question 1

What test equipment would you use to verify that a newly built low-pass filter is suppressing harmonics above 30 MHz?

Accepted Answer

Spectrum analyzer with a tracking generator or a network analyzer

Answer

A spectrum analyzer (with tracking generator) or network analyzer can sweep the filter's frequency response to confirm attenuation at harmonic frequencies.

Question 2

Why is it important to ground the outer shield of a coaxial cable at the point where it enters a building?

Accepted Answer

To protect against lightning-induced surges and reduce RF interference entering the shack

Answer

Bonding the coax shield to a grounding electrode at the building entry point diverts lightning energy to ground before it can travel to equipment inside.

Question 3

What is the function of a bias-T in an antenna system?

Accepted Answer

It allows DC power to be fed through a coaxial cable to power remote devices such as preamps

Answer

A bias-T injects DC voltage onto the center conductor of coax so a remote preamplifier or active antenna can be powered through the feedline.

Question 4

An operator notices their received audio has a 60 Hz hum. Which of the following is the most likely cause?

Accepted Answer

A ground loop or inadequate filtering in the power supply is coupling AC hum into the audio chain

Answer

Sixty-Hz hum almost always traces to power-supply ripple or a ground loop where different equipment grounds differ in potential, modulating audio with AC frequency.

Question 5

What is the purpose of ferrite beads or a common-mode choke on a feedline near the transmitter?

Accepted Answer

To suppress common-mode RF current flowing on the outside of the coax shield

Answer

Common-mode chokes (ferrite beads or wound coax) present high impedance to RF currents traveling on the coax shield's exterior, preventing them from entering the shack.

Ham Radio Technician Test Practice Test

Ham Radio Technician Test Practice Test

Ham Radio Technician Test Equipment & Tools Usage 5