Video Distribution Flashcards

What is the primary purpose of a distribution amplifier (DA) in a video system?

Answer: Split and amplify one signal to multiple outputs without degradation

A distribution amplifier splits one input signal into multiple isolated outputs while restoring signal strength to compensate for split losses.

Which impedance is standard for coaxial video cable used in CCTV and broadcast distribution?

Answer: 75 ohms

75-ohm coaxial cable is the industry standard for video distribution because it minimizes signal loss at video frequencies.

A video signal loses approximately how much level for each 100 feet of RG-59 cable at 3.58 MHz?

Answer: 4 dB

RG-59 coaxial cable has approximately 4 dB of loss per 100 feet at the color subcarrier frequency of 3.58 MHz.

In a star topology video distribution system, what is the main component at the center?

Answer: Distribution amplifier or matrix switcher

Star topologies use a central distribution amplifier or matrix switcher to feed each endpoint individually, ensuring equal signal levels.

What is the correct termination for an unused output port on a passive video splitter?

Answer: Install a 75-ohm terminator

Unterminated ports cause reflections and standing waves; a 75-ohm terminator absorbs the signal and prevents impedance mismatches.

Which type of cable is preferred over RG-59 for long video distribution runs due to lower loss?

Answer: RG-6

RG-6 has a larger center conductor and better shielding than RG-59, resulting in approximately 30% lower attenuation over long distances.

When cascading multiple distribution amplifiers, what problem can accumulate and degrade picture quality?

Answer: Noise and distortion

Each active amplifier stage adds noise and harmonic distortion; cascading too many DAs compounds these impairments and degrades SNR.