RF PREP // FCC AMATEUR RADIO

E3 · Radio Wave Propagation

Amateur Extra · correct answers only, in question-pool order.

E3A01

What is the approximate maximum surface separation between two stations that can communicate by EME?

AnswerAbout 12,000 miles when both stations can see the Moon.

Earth-Moon-Earth communication is possible whenever both stations have the Moon above their usable horizons, allowing nearly opposite points on Earth to share a lunar path.

EXTRAE3 · Radio Wave Propagation

E3A02

What characterizes libration fading on an EME signal?

AnswerFluttery, irregular fading.

The Moon’s apparent motion causes many reflected paths to change phase, producing rapid irregular amplitude variations.

TECH // ELEMENT 2

GENERAL // ELEMENT 3

EXTRA // ELEMENT 4

E3 · Radio Wave Propagation

What is the approximate maximum surface separation between two stations that can communicate by EME?

What characterizes libration fading on an EME signal?

Free amateur radio study, without the tracking.