Ham Radio General Class Test Electrical and RF Safety 5

Question 1

What is the recommended minimum distance from a typical 100-watt HF dipole antenna to protect people in an uncontrolled environment?

Accepted Answer

Varies by frequency but typically several feet to tens of feet depending on frequency

Answer

The safe distance from an HF dipole varies with frequency and power; FCC online calculators and the station evaluation tool help determine the specific distance required.

Question 2

Which mode of operation generally has the highest average power and therefore the greatest RF exposure risk at the same PEP setting?

Accepted Answer

FM voice

Answer

FM is a constant-carrier mode, so at the same peak envelope power, FM produces the highest average power and thus the greatest sustained RF exposure.

Question 3

What is the main reason that RF safety standards differ between controlled and uncontrolled environments?

Accepted Answer

People in controlled environments are trained and can take steps to limit their own exposure

Answer

Trained operators in a controlled environment can monitor and limit their own exposure, so higher field strength limits apply; uncontrolled environments protect uninformed bystanders with stricter limits.

Question 4

What is the primary electrical safety risk when operating a linear amplifier that uses vacuum tubes?

Accepted Answer

Lethal high-voltage DC on the anode supply, sometimes exceeding 2,000 volts

Answer

Tube amplifiers use high-voltage DC supplies, often exceeding 2,000 volts, which is far beyond the lethal threshold and demands extreme care.

Question 5

Why is it advisable to use the 'one hand in pocket' technique when probing high-voltage circuits?

Accepted Answer

To prevent a hand-to-hand current path through the heart if accidental contact occurs

Answer

Keeping one hand in your pocket eliminates the most dangerous hand-to-hand current path through the chest, reducing cardiac risk if you accidentally contact live voltage.

Ham Radio General Class Test Practice Test

Ham Radio General Class Test Practice Test

Ham Radio General Class Test Electrical and RF Safety 5