1.04 UTF-8 J 0 0 1243588 E3A01 What is the maximum separation between two stations communicating by moonbounce? 0 500 miles maximum, if the moon is at perigee 0 2000 miles maximum, if the moon is at apogee 0 5000 miles maximum, if the moon is at perigee 0 Any distance as long as the stations have a mutual lunar window 1 E3A02 What characterizes libration fading of an earth-moon-earth signal? 0 A slow change in the pitch of the CW signal 0 A fluttery irregular fading 1 A gradual loss of signal as the sun rises 0 The returning echo is several hertz lower in frequency than the transmitted signal 0 E3A03 When scheduling EME contacts, which of these conditions will generally result in the least path loss? 0 When the moon is at perigee 1 When the moon is full 0 When the moon is at apogee 0 When the MUF is above 30 MHz 0 E3A04 What type of receiving system is desirable for EME communications? 0 Equipment with very low power output 0 Equipment with very low dynamic range 0 Equipment with very low gain 0 Equipment with very low noise figures 1 E3A05 What transmit and receive time sequencing is normally used on 144 MHz when attempting an earth-moon-earth contact? 0 Two-minute sequences, where one station transmits for a full two minutes and then receives for the following two minutes 1 One-minute sequences, where one station transmits for one minute and then receives for the following one minute 0 Two-and-one-half minute sequences, where one station transmits for a full 2.5 minutes and then receives for the following 2.5 minutes 0 Five-minute sequences, where one station transmits for five minutes and then receives for the following five minutes 0 E3A06 What transmit and receive time sequencing is normally used on 432 MHz when attempting an EME contact? 0 Two-minute sequences, where one station transmits for a full two minutes and then receives for the following two minutes 0 One-minute sequences, where one station transmits for one minute and then receives for the following one minute 0 Two and one half minute sequences, where one station transmits for a full 2.5 minutes and then receives for the following 2.5 minutes 1 Five minute sequences, where one station transmits for five minutes and then receives for the following five minutes 0 E3A07 What frequency range would you normally tune to find EME stations in the 2-meter band? 0 144.000 - 144.001 MHz 0 144.000 - 144.100 MHz 1 144.100 - 144.300 MHz 0 145.000 - 145.100 MHz 0 E3A08 What frequency range would you normally tune to find EME stations in the 70-cm band? 0 430.000 - 430.150 MHz 0 430.100 - 431.100 MHz 0 431.100 - 431.200 MHz 0 432.000 - 432.100 MHz 1 E3A09 When a meteor strikes the earth's atmosphere, a cylindrical region of free electrons is formed at what layer of the ionosphere? 0 The E layer 1 The F1 layer 0 The F2 layer 0 The D layer 0 E3A10 Which range of frequencies is well suited for meteor-scatter communications? 0 1.8 - 1.9 MHz 0 10 - 14 MHz 0 28 - 148 MHz 1 220 - 450 MHz 0 E3A11 What transmit and receive time sequencing is normally used on 144 MHz when attempting a meteor-scatter contact? 0 Two-minute sequences, where one station transmits for a full two minutes and then receives for the following two minutes 0 One-minute sequences, where one station transmits for one minute and then receives for the following one minute 0 15-second sequences, where one station transmits for 15 seconds and then receives for the following 15 seconds 1 30-second sequences, where one station transmits for 30 seconds and then receives for the following 30 seconds 0 E3B01 What is transequatorial propagation? 0 Propagation between two points at approximately the same distance north and south of the magnetic equator 1 Propagation between two points at approximately the same latitude on the magnetic equator 0 Propagation between two continents by way of ducts along the magnetic equator 0 Propagation between two stations at the same latitude 0 E3B02 What is the approximate maximum range for signals using transequatorial propagation? 0 1000 miles 0 2500 miles 0 5000 miles 1 7500 miles 0 E3B03 What is the best time of day for transequatorial propagation? 0 Morning 0 Noon 0 Afternoon or early evening 1 Late at night 0 E3B04 What type of propagation is probably occurring if an HF beam antenna must be pointed in a direction 180 degrees away from a station to receive the strongest signals? 0 Long-path 1 Sporadic-E 0 Transequatorial 0 Auroral 0 E3B05 On what amateur bands can long-path propagation provide signal enhancement? 0 160 to 40 meters 0 30 to 10 meters 0 160 to 10 meters 1 6 meters to 2 meters 0 E3B06 What amateur band consistently yields long-path enhancement using a modest antenna of relatively high gain? 0 80 meters 0 20 meters 1 10 meters 0 6 meters 0 E3B07 What is the typical reason for hearing an echo on the received signal of a station in Europe while directing your HF antenna toward the station? 0 The station's transmitter has poor frequency stability 0 The station's transmitter is producing spurious emissions 0 Auroral conditions are causing a direct and a long-path reflected signal to be received 0 There are two signals being received, one from the most direct path and one from long-path propagation 1 E3B08 What type of propagation is probably occurring if radio signals travel along the terminator between daylight and darkness? 0 Transequatorial 0 Sporadic-E 0 Long-path 0 Gray-line 1 E3B09 At what time of day is gray-line propagation most prevalent? 0 Twilight, at sunrise and sunset 1 When the sun is directly above the location of the transmitting station 0 When the sun is directly overhead at the middle of the communications path between the two stations 0 When the sun is directly above the location of the receiving station 0 E3B10 What is the cause of gray-line propagation? 0 At midday the sun, being directly overhead, superheats the ionosphere causing increased refraction of radio waves 0 At twilight solar absorption drops greatly while atmospheric ionization is not weakened enough to reduce the MUF 1 At darkness solar absorption drops greatly while atmospheric ionization remains steady 0 At mid afternoon the sun heats the ionosphere, increasing radio wave refraction and the MUF 0 E3B11 What communications are possible during gray-line propagation? 0 Contacts up to 2,000 miles only on the 10-meter band 0 Contacts up to 750 miles on the 6- and 2-meter bands 0 Contacts up to 8,000 to 10,000 miles on three or four HF bands 1 Contacts up to 12,000 to 15,000 miles on the 2 meter and 70 centimeter bands 0 E3C01 What effect does auroral activity have upon radio communications? 0 The readability of SSB signals increases 0 FM communications are clearer 0 CW signals have a clearer tone 0 CW signals have a fluttery tone 1 E3C02 What is the cause of auroral activity? 0 A high sunspot level 0 A low sunspot level 0 The emission of charged particles from the sun 1 Meteor showers concentrated in the northern latitudes 0 E3C03 Where in the ionosphere does auroral activity occur? 0 At F-region height 0 In the equatorial band 0 At D-region height 0 At E-region height 1 E3C04 Which emission mode is best for auroral propagation? 0 CW 1 SSB 0 FM 0 RTTY 0 E3C05 What causes selective fading? 0 Small changes in beam heading at the receiving station 0 Phase differences between radio-wave components of the same transmission, as experienced at the receiving station 1 Large changes in the height of the ionosphere at the receiving station ordinarily occurring shortly after either sunrise or sunset 0 Time differences between the receiving and transmitting stations 0 E3C06 How does the bandwidth of a transmitted signal affect selective fading? 0 It is more pronounced at wide bandwidths 1 It is more pronounced at narrow bandwidths 0 It is the same for both narrow and wide bandwidths 0 The receiver bandwidth determines the selective fading effect 0 E3C07 How much farther does the VHF/UHF radio-path horizon distance exceed the geometric horizon? 0 By approximately 15% of the distance 1 By approximately twice the distance 0 By approximately one-half the distance 0 By approximately four times the distance 0 E3C08 For a 3-element beam antenna with horizontally mounted elements, how does the main lobe takeoff angle vary with height above flat ground? 0 It increases with increasing height 0 It decreases with increasing height 1 It does not vary with height 0 It depends on E-region height, not antenna height 0 E3C09 What is the name of the high-angle wave in HF propagation that travels for some distance within the F2 region? 0 Oblique-angle ray 0 Pedersen ray 1 Ordinary ray 0 Heaviside ray 0 E3C10 What effect is usually responsible for propagating a VHF signal over 500 miles? 0 D-region absorption 0 Faraday rotation 0 Tropospheric ducting 1 Moonbounce 0 E3C11 For a 3-element beam antenna with horizontally mounted elements, how does the main lobe takeoff angle vary with the downward slope of the ground (moving away from the antenna)? 0 It increases as the slope gets steeper 0 It decreases as the slope gets steeper 1 It does not depend on the ground slope 0 It depends of the F-region height 0 E3C12 In the northern hemisphere, in which direction should a directional antenna be pointed to take maximum advantage of auroral propagation? 0 South 0 North 1 East 0 West 0 E3C13 As the frequency of a signal is increased, how does its ground wave propagation change? 0 It increases 0 It decreases 1 It stays the same 0 Radio waves don't propagate along the earth's surface 0 E3C14 What typical polarization does ground-wave propagation have? 0 Vertical 1 Horizontal 0 Circular 0 Elliptical 0 E3C15 Why does the radio-path horizon distance exceed the geometric horizon? 0 E-region skip 0 D-region skip 0 Auroral skip 0 Radio waves may be bent 1