Free Ham Radio Technician III Questions And Answers

Question 1

What are RACES and ARES similar to?

Accepted Answer

Both organizations broadcast road and weather traffic information

Answer

RACES (Radio Amateur Civil Emergency Service) and ARES (Amateur Radio Emergency Service) are both volunteer organizations composed of licensed amateur radio operators. While their primary mission is to provide emergency communications during disasters, they can also support public service events, which may include broadcasting road and weather traffic information. This type of information dissemination is a form of public service communication that both organizations are equipped to handle, especially in situations where normal communication infrastructure is compromised.

Question 2

What occurs when an FM transmitter's deviation is raised?

Accepted Answer

Its signal occupies more bandwidth

Answer

When an FM transmitter's deviation is raised, its signal occupies more bandwidth. Frequency modulation works by varying the carrier frequency in proportion to the amplitude of the modulating signal; the amount of this variation is called deviation. According to Carson's Rule, increasing the frequency deviation directly increases the range of frequencies the modulated signal spans, thus requiring a wider bandwidth for transmission.

Question 3

What happens if an FM transmitter's deviation is increased?

Accepted Answer

Its signal occupies more bandwidth

Answer

Increasing an FM transmitter's deviation causes its signal to occupy more bandwidth. Deviation refers to the maximum shift in frequency from the carrier frequency caused by the modulating signal. A larger deviation means the carrier frequency swings over a wider range, which in turn spreads the signal across a broader spectrum of frequencies, thus increasing the required bandwidth for transmission.

Question 4

What is a typical offset for repeaters in the 70 cm band?

Accepted Answer

Plus or minus 5 MHz

Answer

A typical offset for repeaters in the 70 cm band is plus or minus 5 MHz. This offset refers to the difference between the repeater's transmit and receive frequencies. For example, if a repeater receives on 444.000 MHz, it might transmit on 449.000 MHz (+5 MHz offset) or 439.000 MHz (-5 MHz offset), allowing for full-duplex communication without the user's transmitter interfering with their own receiver.

Question 5

Which of the following is an FCC regulation governing the power levels used in amateur bands when conditions are normal and undistressed?

Accepted Answer

Use the least amount of power required to carry out the desired communication while not exceeding the maximum power permitted on a given band.

Answer

An FCC regulation governing power levels in amateur bands under normal conditions mandates using the least amount of power required to carry out the desired communication, while not exceeding the maximum power permitted on a given band. This principle, known as 'minimum power necessary,' aims to minimize interference to other users and services. While maximums like 1500 watts PEP exist for some bands, operators are always expected to use only the power needed for a reliable contact.

Ham Radio Technician Test Practice Test

Ham Radio Technician Test Practice Test

Free Ham Radio Technician III Questions And Answers