E3A01:

What is the approximate maximum separation measured along the surface of the Earth between two stations communicating by Moon bounce?

  1. 500 miles, if the Moon is at perigee
  2. 2000 miles, if the Moon is at apogee
  3. 5000 miles, if the Moon is at perigee
  4. 12,000 miles, if the Moon is visible by both stations

E3A02:

What characterizes libration fading of an EME signal?

  1. A slow change in the pitch of the CW signal
  2. A fluttery irregular fading
  3. A gradual loss of signal as the Sun rises
  4. The returning echo is several Hertz lower in frequency than the transmitted signal

E3A03:

When scheduling EME contacts, which of these conditions will generally result in the least path loss?

  1. When the Moon is at perigee
  2. When the Moon is full
  3. When the Moon is at apogee
  4. When the MUF is above 30 MHz

E3A04:

What do Hepburn maps predict?

  1. Sporadic E propagation
  2. Locations of auroral reflecting zones
  3. Likelihood of rain-scatter along cold or warm fronts
  4. Probability of tropospheric propagation

E3A05:

Tropospheric propagation of microwave signals often occurs along what weather related structure?

  1. Gray-line
  2. Lightning discharges
  3. Warm and cold fronts
  4. Sprites and jets

E3A06:

Which of the following is required for microwave propagation via rain scatter?

  1. Rain droplets must be electrically charged
  2. Rain droplets must be within the E layer
  3. The rain must be within radio range of both stations
  4. All of these choices are correct

E3A07:

Atmospheric ducts capable of propagating microwave signals often form over what geographic feature?

  1. Mountain ranges
  2. Forests
  3. Bodies of water
  4. Urban areas

E3A08:

When a meteor strikes the Earth's atmosphere, a cylindrical region of free electrons is formed at what layer of the ionosphere?

  1. The E layer
  2. The F1 layer
  3. The F2 layer
  4. The D layer

E3A09:

Which of the following frequency range is most suited for meteor scatter communications?

  1. 1.8 MHz - 1.9 MHz
  2. 10 MHz - 14 MHz
  3. 28 MHz - 148 MHz
  4. 220 MHz - 450 MHz

E3A10:

Which type of atmospheric structure can create a path for microwave propagation?

  1. The jet stream
  2. Temperature inversion
  3. Wind shear
  4. Dust devil

E3A11:

What is a typical range for tropospheric propagation of microwave signals?

  1. 10 miles to 50 miles
  2. 100 miles to 300 miles
  3. 1200 miles
  4. 2500 miles

E3A12:

What is the cause of auroral activity?

  1. The interaction in the F2 layer between the solar wind and the Van Allen belt
  2. A low sunspot level combined with tropospheric ducting
  3. The interaction in the E layer of charged particles from the Sun with the Earth's magnetic field
  4. Meteor showers concentrated in the extreme northern and southern latitudes

E3A13:

Which emission mode is best for aurora propagation?

  1. CW
  2. SSB
  3. FM
  4. RTTY

E3A14:

From the contiguous 48 states, in which approximate direction should an antenna be pointed to take maximum advantage of aurora propagation?

  1. South
  2. North
  3. East
  4. West

E3A15:

What is an electromagnetic wave?

  1. A wave of alternating current, in the core of an electromagnet
  2. A wave consisting of two electric fields at parallel right angles to each other
  3. A wave consisting of an electric field and a magnetic field oscillating at right angles to each other
  4. A wave consisting of two magnetic fields at right angles to each other

E3A16:

Which of the following best describes electromagnetic waves traveling in free space?

  1. Electric and magnetic fields become aligned as they travel
  2. The energy propagates through a medium with a high refractive index
  3. The waves are reflected by the ionosphere and return to their source
  4. Changing electric and magnetic fields propagate the energy

E3A17:

What is meant by circularly polarized electromagnetic waves?

  1. Waves with an electric field bent into a circular shape
  2. Waves with a rotating electric field
  3. Waves that circle the Earth
  4. Waves produced by a loop antenna