VDV Video Distribution 3 — Questions and Answers
Question 1: What is the function of a video matrix switcher in a large distribution system?
- Amplify all video signals simultaneously
- Route any input to any output in any combination (Correct answer)
- Convert video formats between standards
- Filter noise from video signals
Correct answer: Route any input to any output in any combination
A matrix switcher allows any input source to be routed to one or more outputs independently, providing full crosspoint switching flexibility.
Question 2: What does HDCP stand for in the context of video distribution?
- High Definition Color Processing
- High-bandwidth Digital Content Protection (Correct answer)
- Horizontal Digital Clock Pulse
- High Dynamic Contrast Protocol
Correct answer: High-bandwidth Digital Content Protection
HDCP (High-bandwidth Digital Content Protection) is a copy-protection scheme that encrypts digital video signals over HDMI, DVI, and DisplayPort connections.
Question 3: A balun is used in video distribution primarily to accomplish which of the following?
- Convert 75-ohm coax to twisted-pair transmission (Correct answer)
- Boost signal level over fiber optic cable
- Split one signal into multiple outputs
- Convert composite to HDMI video
Correct answer: Convert 75-ohm coax to twisted-pair transmission
Video baluns allow analog or digital video to travel over Category cable (twisted pair) by converting the unbalanced coax signal to a balanced differential signal.
Question 4: In HDMI distribution, what is the maximum cable length generally recommended without a signal booster for standard 1080p?
- 5 feet
- 25 feet
- 50 feet (Correct answer)
- 100 feet
Correct answer: 50 feet
Passive HDMI cables are typically reliable up to about 50 feet for 1080p; beyond that, active cables or extenders are recommended to maintain signal integrity.
Question 5: Which technology allows HDMI signals to be extended over Cat5e/Cat6 cable beyond 100 feet?
- HDMI ARC
- HDBaseT (Correct answer)
- CEC bridging
- HDMI splitter
Correct answer: HDBaseT
HDBaseT is a connectivity standard that transmits uncompressed HD video, audio, power, and control signals over a single Cat5e/Cat6 cable up to 100 meters.
Question 6: When installing a video distribution system in a building, where should the head-end equipment typically be located?
- At the farthest point from displays
- In a central location to minimize cable runs (Correct answer)
- Near windows for cooling
- Adjacent to the electrical main panel only
Correct answer: In a central location to minimize cable runs
Centralizing head-end equipment minimizes total cable length, reduces signal loss, and simplifies maintenance access.
Question 7: What signal impairment appears as a faint ghost image offset horizontally on an analog video display?
- Noise
- Reflection or multipath interference (Correct answer)
- Sync instability
- Chroma smear
Correct answer: Reflection or multipath interference
Reflections caused by impedance mismatches or unterminated cable stubs cause delayed copies of the signal to appear as ghost images on the display.
VDV Video Distribution 3
What is the function of a video matrix switcher in a large distribution system?