T9B

Question 1

T9B01 (B)
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

Answer 1

2 To reduce signal loss

Question 2

T9B02 (B)
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

Answer 2

2 50 ohms

Question 3

T9B04 (A)
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

Answer 3

1 It matches the antenna system impedance to the

transceiver’s output impedance

Question 4

T9B05 (D)
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

Answer 4

4 The loss increases

Question 5

T9B06 (B)
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

Answer 5

2 A Type N connector

Question 6

T9B08 (A)
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

Answer 6

1 To prevent an increase in feed line loss

Question 7

T9B10 (C)
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

Answer 7

3 RG-8 cable has less loss at a given frequency

Question 8

T9B11 (C)
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

Answer 8

3 Air-insulated hard line