Topic T9B Quick Review Audio


Why is it important to have low SWR when using coaxial cable feed line?

  1. To reduce television interference
  2. To reduce signal loss
  3. To prolong antenna life
  4. All of these choices are correct


What is the impedance of most coaxial cables used in amateur radio installations?

  1. 8 ohms
  2. 50 ohms
  3. 600 ohms
  4. 12 ohms


Why is coaxial cable the most common feed line selected for amateur radio antenna systems?

  1. It is easy to use and requires few special installation considerations
  2. It has less loss than any other type of feed line
  3. It can handle more power than any other type of feed line
  4. It is less expensive than any other type of feed line


What is the major function of an antenna tuner (antenna coupler)?

  1. It matches the antenna system impedance to the transceiver's output impedance
  2. It helps a receiver automatically tune in weak stations
  3. It allows an antenna to be used on both transmit and receive
  4. It automatically selects the proper antenna for the frequency band being used


In general, what happens as the frequency of a signal passing through coaxial cable is increased?

  1. The characteristic impedance decreases
  2. The loss decreases
  3. The characteristic impedance increases
  4. The loss increases


Which of the following connectors is most suitable for frequencies above 400 MHz?

  1. A UHF (PL-259/SO-239) connector
  2. A Type N connector
  3. An RS-213 connector
  4. A DB-25 connector


Which of the following is true of PL-259 type coax connectors?

  1. They are preferred for microwave operation
  2. They are watertight
  3. They are commonly used at HF frequencies
  4. They are a bayonet type connector


Why should coax connectors exposed to the weather be sealed against water intrusion?

  1. To prevent an increase in feed line loss
  2. To prevent interference to telephones
  3. To keep the jacket from becoming loose
  4. All of these choices are correct


What can cause erratic changes in SWR readings?

  1. The transmitter is being modulated
  2. A loose connection in an antenna or a feed line
  3. The transmitter is being over-modulated
  4. Interference from other stations is distorting your signal


What is the electrical difference between RG-58 and RG-8 coaxial cable?

  1. There is no significant difference between the two types
  2. RG-58 cable has two shields
  3. RG-8 cable has less loss at a given frequency
  4. RG-58 cable can handle higher power levels


Which of the following types of feed line has the lowest loss at VHF and UHF?

  1. 50-ohm flexible coax
  2. Multi-conductor unbalanced cable
  3. Air-insulated hard line
  4. 75-ohm flexible coax