What is the authorized mode of emission for the international radiotelephone distress frequency, 2182 kHz?

What is the authorized mode of emission for the international radiotelephone distress frequency, 2182 kHz?

• A. H3E (single-sideband full carrier)
• B. A3E (double-sideband full carrier)
• C. B3E (double-sideband suppressed carrier)
• D. C3F (frequency-modulated)

Answer: (A)

The correct mode of emission for the international radiotelephone distress frequency, 2182 kHz, is single-sideband full carrier, commonly designated as H3E. This choice is crucial because the distress frequency is primarily used for emergency communications, and single-sideband modulation allows for clearer transmission in conditions where bandwidth is limited or interference is present. Using single-sideband full carrier ensures that the voice signals transmitted on this frequency maintain higher intelligibility and are less susceptible to noise interference. In contrast, the other modes—whether double-sideband full carrier, double-sideband suppressed carrier, or frequency-modulated—do not offer the same clarity and efficiency needed for distress communications. Double-sideband modes would typically consume more bandwidth without significant advantages in clarity and could lead to potential confusion during emergency situations. Frequency modulation is not used on this frequency as it does not provide the required compatibility for distress and safety communication as dictated by international regulations. Thus, H3E is the appropriate answer for emergency use at 2182 kHz.

The correct mode of emission for the international radiotelephone distress frequency, 2182 kHz, is single-sideband full carrier, commonly designated as H3E. This choice is crucial because the distress frequency is primarily used for emergency communications, and single-sideband modulation allows for clearer transmission in conditions where bandwidth is limited or interference is present.

Using single-sideband full carrier ensures that the voice signals transmitted on this frequency maintain higher intelligibility and are less susceptible to noise interference.

In contrast, the other modes—whether double-sideband full carrier, double-sideband suppressed carrier, or frequency-modulated—do not offer the same clarity and efficiency needed for distress communications. Double-sideband modes would typically consume more bandwidth without significant advantages in clarity and could lead to potential confusion during emergency situations. Frequency modulation is not used on this frequency as it does not provide the required compatibility for distress and safety communication as dictated by international regulations. Thus, H3E is the appropriate answer for emergency use at 2182 kHz.