Key Topic 82: Types of Transmissions

Question 1

3-82M1: What term describes a wide-bandwidth communications system in which the RF carrier frequency varies according to some predetermined sequence?

A. Amplitude compandored single sideband.
B. SITOR.
C. Time-domain frequency modulation.
D. Spread spectrum communication.

Answer 1

D. Spread spectrum communication.

Question 2

3-82M2: Name two types of spread spectrum systems used in most RF communications applications?

A. AM and FM.
B. QPSK or QAM.
C. Direct Sequence and Frequency Hopping.
D. Frequency Hopping and APSK.

Answer 2

C. Direct Sequence and Frequency Hopping.

Question 3

3-82M3: What is the term used to describe a spread spectrum communications system where the center frequency of a conventional carrier is altered many times per second in accordance with a pseudo-random list of channels?

A. Frequency hopping.
B. Direct sequence.
C. Time-domain frequency modulation.
D. Frequency compandored spread spectrum.

Answer 3

A. Frequency hopping.

Question 4

3-82M4: A TDMA radio uses what to carry the multiple conversations sequentially?

A. Separate frequencies.
B. Separate pilot tones.
C. Separate power levels.
D. Separate time slots.

Answer 4

D. Separate time slots.

Question 5

3-82M5: Which of the following statements about SSB voice transmissions is correct?

A. They use A3E emission which are produced by modulating the final amplifier.
B. They use F3E emission which is produced by phase shifting the carrier.
C. They normally use J3E emissions, which consists of one sideband and a suppressed carrier.
D. They may use A1A emission to suppress the carrier.

Answer 5

C. They normally use J3E emissions, which consists of one sideband and a suppressed carrier.

Question 6

3-82M6: What are the two most-used PCS (Personal Communications Systems) coding techniques used to separate different calls?

A. QPSK and QAM.
B. CDMA and GSM.
C. ABCD and SYZ.
D. AM and Frequency Hopping.

Answer 6

B. CDMA and GSM.