Basic Qualification · B-003 Station assembly, practice and safety · B-003-013-009
Why isn't FM used as an amateur radio emission mode below 28 MHz?
- A The bandwidth would exceed limits in the regulations
- B The transmitter efficiency for this mode is low
- C Harmonics could not be attenuated to practical levels
- D The frequency stability would not be adequate
Correct answer: A — The bandwidth would exceed limits in the regulations. From the official ISED question bank, verified word for word.
Why
Frequency Modulation creates a signal that takes up much more space on the radio spectrum than other modes. The full explanation — and one for every question — is in Pro.
Practise this section
Building a station safely: power supplies, grounding, RF exposure, lightning, feedline routing, and what a transmitter, receiver and transceiver actually do.