VDV Testing & Troubleshooting 2

Question 1

A technician measures -3.5 dB return loss on a coaxial cable connector. What does this indicate?

Accepted Answer

Moderate signal reflection due to impedance mismatch

Answer

A return loss of -3.5 dB indicates significant signal reflection back toward the source, which is caused by an impedance mismatch at the connector.

Question 2

When using a toner and probe kit to trace a cable, the probe produces no tone on any cable in a bundle. What is the most likely cause?

Accepted Answer

The toner is not connected to the correct pair or is faulty

Answer

If no tone is detected on any cable, the most likely cause is that the toner is not properly connected to the target cable or the toner unit itself is malfunctioning.

Question 3

A VoIP phone loses audio quality intermittently during calls. Which test tool best identifies the root cause?

Accepted Answer

Network packet analyzer (protocol analyzer)

Answer

A protocol analyzer (such as Wireshark) captures packets to reveal jitter, packet loss, and latency—the primary causes of intermittent VoIP audio degradation.

Question 4

A coaxial cable run tests with higher-than-expected attenuation. Which of the following is the LEAST likely cause?

Accepted Answer

Low ambient temperature

Answer

Low ambient temperature actually reduces attenuation slightly; excessive length, physical damage, and impedance mismatches are all common causes of elevated attenuation.

Question 5

During a CATV signal level sweep test, a technician notices a 6 dB drop at all frequencies above 550 MHz. What is the most probable cause?

Accepted Answer

Water-damaged cable segment acting as a high-frequency low-pass filter

Answer

Water ingress into coaxial cable or connectors creates a low-pass filter effect, causing greater attenuation at higher frequencies.

(VDV) Voice Data Video Technician Certified Practice Test

(VDV) Voice Data Video Technician Certified Practice Test

VDV Testing & Troubleshooting 2