Extra exam question E3A09
Subelement E3, RADIO WAVE PROPAGATION· Group E3A
Which of the following frequency ranges is most suited for meteor-scatter communications?
- A.1.8 MHz - 1.9 MHz
- B.10 MHz - 14 MHz
- C.28 MHz - 148 MHz (correct answer)
- D.220 MHz - 450 MHz
WhyThe frequency range best suited for meteor-scatter communications is roughly 28 MHz to 148 MHz. Meteor-scatter communication works best in the range from about 28 MHz up through 148 MHz, spanning 10 meters through 2 meters, where signal wavelengths are well matched to the size and duration of a meteor's ionization trail, answer C. Lower HF frequencies like 1.8-1.9 MHz and 10-14 MHz don't reflect efficiently off these brief trails, and frequencies as high as 220-450 MHz are generally too high for reliable meteor-scatter propagation.
Published 2026-08-28 · Last updated 2026-08-28 · Question text is verbatim from the 2024-2028 NCVEC Element 4 pool (public domain); the explanation above is original writing, see our methodology.
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