E9D01:

How does the gain of an ideal parabolic dish antenna change when the operating frequency is doubled?

  1. Gain does not change
  2. Gain is multiplied by 0.707
  3. Gain increases by 6 dB
  4. Gain increases by 3 dB

E9D02:

How can linearly polarized Yagi antennas be used to produce circular polarization?

  1. Stack two Yagis fed 90 degrees out of phase to form an array with the respective elements in parallel planes
  2. Stack two Yagis fed in phase to form an array with the respective elements in parallel planes
  3. Arrange two Yagis perpendicular to each other with the driven elements at the same point on the boom fed 90 degrees out of phase
  4. Arrange two Yagis collinear to each other with the driven elements fed 180 degrees out of phase

E9D03:

Where should a high Q loading coil be placed to minimize losses in a shortened vertical antenna?

  1. Near the center of the vertical radiator
  2. As low as possible on the vertical radiator
  3. As close to the transmitter as possible
  4. At a voltage node

E9D04:

Why should an HF mobile antenna loading coil have a high ratio of reactance to resistance?

  1. To swamp out harmonics
  2. To maximize losses
  3. To minimize losses
  4. To minimize the Q

E9D05:

What is a disadvantage of using a multiband trapped antenna?

  1. It might radiate harmonics
  2. It radiates the harmonics and fundamental equally well
  3. It is too sharply directional at lower frequencies
  4. It must be neutralized

E9D06:

What happens to the bandwidth of an antenna as it is shortened through the use of loading coils?

  1. It is increased
  2. It is decreased
  3. No change occurs
  4. It becomes flat

E9D07:

What is an advantage of using top loading in a shortened HF vertical antenna?

  1. Lower Q
  2. Greater structural strength
  3. Higher losses
  4. Improved radiation efficiency

E9D08:

What happens as the Q of an antenna increases?

  1. SWR bandwidth increases
  2. SWR bandwidth decreases
  3. Gain is reduced
  4. More common-mode current is present on the feed line

E9D09:

What is the function of a loading coil used as part of an HF mobile antenna?

  1. To increase the SWR bandwidth
  2. To lower the losses
  3. To lower the Q
  4. To cancel capacitive reactance

E9D10:

What happens to feed point impedance at the base of a fixed length HF mobile antenna as the frequency of operation is lowered?

  1. The radiation resistance decreases and the capacitive reactance decreases
  2. The radiation resistance decreases and the capacitive reactance increases
  3. The radiation resistance increases and the capacitive reactance decreases
  4. The radiation resistance increases and the capacitive reactance increases

E9D11:

Which of the following types of conductors would be best for minimizing losses in a station's RF ground system?

  1. A resistive wire, such as spark plug wire
  2. A wide flat copper strap
  3. A cable with six or seven 18 gauge conductors in parallel
  4. A single 12 gauge or 10 gauge stainless steel wire

E9D12:

Which of the following would provide the best RF ground for your station?

  1. A 50 ohm resistor connected to ground
  2. An electrically short connection to a metal water pipe
  3. An electrically short connection to 3 or 4 interconnected ground rods driven into the Earth
  4. An electrically short connection to 3 or 4 interconnected ground rods via a series RF choke

E9D13:

What usually occurs if a Yagi antenna is designed solely for maximum forward gain?

  1. The front-to-back ratio increases
  2. The front-to-back ratio decreases
  3. The frequency response is widened over the whole frequency band
  4. The SWR is reduced