CMRT Installation & Maintenance Procedures 2

Question 1

When installing a marine radar antenna on a mast, what is the minimum safe clearance recommended between the radar beam and the highest point where crew members may stand?

Accepted Answer

3 meters

Answer

A minimum 3-meter clearance between the rotating radar beam and any occupied crew area is standard safety practice to limit RF exposure.

Question 2

During radar installation, coaxial cable runs should be secured at intervals no greater than:

Accepted Answer

120 cm (48 inches)

Answer

Coaxial cables should be supported at maximum 120 cm intervals to prevent excessive bending stress and signal degradation from cable movement.

Question 3

What is the primary reason for installing ferrite chokes on radar power supply leads near the transceiver unit?

Accepted Answer

Suppress conducted RF interference

Answer

Ferrite chokes suppress high-frequency conducted emissions that can travel along power leads and interfere with other electronic equipment.

Question 4

When aligning a radar scanner after installation, heading marker alignment is verified by:

Accepted Answer

Comparing the radar heading line to a known fixed bearing

Answer

The heading marker is aligned by rotating the antenna until the radar heading line corresponds precisely with a charted fixed object at a known bearing.

Question 5

Radar waveguide sections on a vessel should be pressure-tested with dry nitrogen or dry air to check for:

Accepted Answer

Moisture ingress and pressure integrity

Answer

Pressurizing waveguide with dry gas reveals leaks and verifies the system will resist moisture infiltration that degrades RF transmission.

(CMRT) Certified Marine Radar Technician Practice Test

(CMRT) Certified Marine Radar Technician Practice Test

CMRT Installation & Maintenance Procedures 2