Which of the following types of modulation is common for data emissions below 30 MHz?
A. DTMF tones modulating an FM signal
B. FSK
C. Pulse modulation
D. Spread spectrum



Answer :

Answer:

The correct answer is:

B. FSK (Frequency Shift Keying)

Explanation: FSK modulation, which involves shifting the frequency of a carrier signal to represent different digital symbols, is commonly used for data emissions below 30 MHz. This modulation technique is well-suited for radio communication in this frequency range and is widely used in applications such as amateur radio, maritime communication, and industrial telemetry.