CBT RF Transmission & Antenna Systems 2

Question 1

In broadcast engineering, what does ERP stand for and what does it represent?

Accepted Answer

Effective Radiated Power — transmitter power multiplied by antenna gain relative to a dipole

Answer

Effective Radiated Power — the actual power delivered to the antenna terminals

Answer

Equivalent Resonant Power — power at resonance frequency of the antenna

Answer

Effective Resonant Power — power reflected by the transmission line

Question 2

What is the primary function of a circulator in a high-power broadcast transmitter output stage?

Accepted Answer

To protect the transmitter PA from damage caused by high reflected power

Answer

To boost the carrier frequency before reaching the antenna

Answer

To combine signals from two separate transmitter chains

Answer

To convert horizontal polarization to circular polarization

Question 3

How does antenna height above average terrain (HAAT) affect FM broadcast coverage?

Accepted Answer

Higher HAAT increases coverage by extending the radio horizon

Answer

Higher HAAT decreases coverage due to increased atmospheric absorption

Answer

HAAT only affects AM coverage, not FM

Answer

Higher HAAT requires reduced transmitter power by FCC rule

Question 4

What is the purpose of pressurizing a coaxial transmission line with dry nitrogen?

Accepted Answer

To prevent moisture ingress that would increase line losses and cause arcing

Answer

To increase the dielectric constant and reduce signal velocity

Answer

To raise the characteristic impedance from 50 to 75 ohms

Answer

To lubricate the inner conductor for easier installation

Question 5

A broadcast antenna has a horizontal radiation pattern (HRP) that is not perfectly omnidirectional. What is this called?

Accepted Answer

Directional antenna pattern

Answer

Elliptical pattern

Answer

Null fill radiation

Answer

Beam tilt profile

Question 6

What is the typical power loss per 100 feet for 1-5/8 inch Heliax coaxial cable at 100 MHz?

Accepted Answer

Approximately 0.5 dB per 100 feet

Answer

Approximately 0.1 dB per 100 feet

Answer

Approximately 2.0 dB per 100 feet

Answer

Approximately 5.0 dB per 100 feet

Question 7

What FCC rule governs the maximum allowable antenna height and power for full-power FM broadcast stations?

Accepted Answer

47 CFR Part 73

Answer

47 CFR Part 15

Answer

47 CFR Part 97

Answer

47 CFR Part 74