HAM RF Safety and Station Grounding 2

Question 1

What is the primary purpose of a single-point (star) ground system in an amateur radio station?

Accepted Answer

To prevent ground loops and reduce RF interference

Answer

To increase antenna radiation efficiency

Answer

To protect against lightning by diverting current to earth ground

Answer

To lower the receiver noise floor by adding capacitance

Question 2

What is a 'ground loop' in a ham radio station?

Accepted Answer

Multiple ground paths that form a closed loop, carrying unwanted circulating currents

Answer

A circular antenna that provides gain and causes interference to nearby stations

Answer

A coaxial feedline loop used for noise cancellation that reduces antenna efficiency

Answer

A safety ground wire routed in a circle for mechanical security

Question 3

What type of conductor is recommended for RF bonding between equipment chassis in an amateur station?

Accepted Answer

Flat copper braid or strap for its low inductance

Answer

Round 10 AWG copper wire for its high current capacity

Answer

Stainless steel wire rope for mechanical strength

Answer

Aluminum foil tape for ease of installation

Question 4

According to FCC Part 97, what is required of amateur stations with respect to RF safety compliance?

Accepted Answer

Stations must not expose people to RF fields exceeding the applicable MPE limits

Answer

All stations must use a calibrated RF power meter at all times

Answer

All antennas must be installed at least 10 meters above ground level

Answer

New installations require an FCC inspection before they may begin operation

Question 5

What effect does increasing antenna height generally have on RF exposure of people at ground level?

Accepted Answer

It reduces near-field exposure by increasing the distance between the antenna and people

Answer

It increases near-field exposure by concentrating the radiation pattern downward

Answer

Height has no measurable effect on near-field exposure at ground level

Answer

It only affects far-field exposure at distances beyond one wavelength

Question 6

What is the purpose of an RF choke (ferrite bead or toroid) placed on a coaxial feedline entering the shack?

Accepted Answer

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

Answer

To increase the antenna's radiation efficiency on all bands

Answer

To reduce the characteristic impedance of the cable to 50 ohms

Answer

To protect equipment from lightning surges traveling on the feedline

Question 7

When evaluating RF exposure for a directional antenna, which areas must be included in the analysis?

Accepted Answer

All areas accessible to people, including regions exposed to side lobes and back lobes

Answer

Only the area directly in the main lobe of the antenna pattern

Answer

Only the area within the antenna's half-power beamwidth

Answer

Only areas that receive more than 10% of the total radiated power