Ham Radio Technician Test Radio Wave Propagation & Modulation 3

Question 1

What happens to the MUF (Maximum Usable Frequency) when solar activity decreases?

Accepted Answer

MUF decreases because the ionosphere is less ionized

Answer

Lower solar activity means less UV radiation ionizing the ionosphere, which reduces the MUF and limits long-distance HF propagation to lower frequencies.

Question 2

What is the purpose of a CTCSS tone on an FM transmission?

Accepted Answer

To access repeaters or squelch a receiver only when the correct tone is present

Answer

CTCSS (Continuous Tone-Coded Squelch System) is a subaudible tone transmitted to open a repeater's receiver or a radio's squelch only when the matching tone is present.

Question 3

Why does AM voice occupy more bandwidth than SSB?

Accepted Answer

AM transmits both sidebands plus a full carrier, while SSB suppresses one sideband and the carrier

Answer

A standard AM signal transmits an upper sideband, a lower sideband, and a carrier, using roughly twice the bandwidth of SSB which transmits only one sideband.

Question 4

What is multipath propagation?

Accepted Answer

Signals arriving at a receiver via two or more different paths, causing interference

Answer

Multipath occurs when a transmitted signal reaches the receiver by two or more different routes (e.g., direct path plus a reflected path), which can cause phase cancellation and fading.

Question 5

At what time of day is the D layer absorption of HF signals greatest?

Accepted Answer

Local noon when solar radiation is strongest

Answer

The D layer is most heavily ionized at local noon when the sun is at its highest and solar UV radiation is most intense, causing maximum absorption of lower HF frequencies.

Ham Radio Technician Test Practice Test

Ham Radio Technician Test Practice Test

Ham Radio Technician Test Radio Wave Propagation & Modulation 3