What mode of transmission is commonly used by amateur radio satellites?

• A. Digital only
• B. FM only
• C. SSB, FM, CW/data
• D. Only voice communications

Answer: (C)

Amateur radio satellites typically utilize a variety of transmission modes to accommodate different communication needs, which is why the answer that includes SSB (Single Sideband), FM (Frequency Modulation), and CW/data is correct. Each of these modes serves specific purposes:

• SSB is often used for long-distance voice communication because it allows for efficient use of bandwidth and has a better signal-to-noise ratio compared to AM.

• FM is widely employed for satellite communication due to its resilience to noise and ability to provide clear audio quality, making it suitable for straightforward voice communication.

• CW (Continuous Wave) is commonly used for data transmission and can be very effective in weak signal conditions. It also facilitates contacts with minimal equipment and is popular among amateur operators.

The versatility of using multiple modes allows amateur radio operators to effectively communicate under varying conditions and enhances the overall utility of satellite operations. Other options like "Digital only," "FM only," or "Only voice communications" limit the capabilities and flexibility that operators have when utilizing satellite resources.