Transmition Lines

Question 0

What term is used for the end of the transmission line that is connected to a transmitter?

Answer 0

Input end
Generator end
Transmitter end
Sending end 
Source

Question 1

What connecting link is used to transfer energy from a radio transmitter to its antenna?

Answer 1

Transmission line

Question 2

What term is used for the end of the transmission line that is connected to an antenna?

Answer 2

Out put end
Receiving end
Load end
Sink

Question 3

List 5 types of transmission lines in use today.

Answer 3

Parallel two-wire
Twisted pair
Shielded pair
Coaxial line
Wave guide

Question 4

Name 2 if the 3 uses of a two-wire open line.

Answer 4

Power lines
Rural phone lines
Telegraph lines

Question 5

What are the 2 primary disadvantages is a two-wire open line.

Answer 5

High radiation loss

Noise pickup

Question 6

What type of transmission line is often used to connect a TV set to its antenna

Answer 6

Twin lead

Question 7

What is the primary advantage if a shielded pair?

Answer 7

The conductors are balanced to ground.

Question 8

What are the 2 types of coaxial lines in use today?

Answer 8

Air coaxial (rigid)
Solid coaxial (flexible)

Question 9

What is the chief advantage if the air coaxial line?

Answer 9

Minimizes radiation loss

Question 10

List 3 disadvantages of the air coaxial line.

Answer 10

Expensive to construct
Must be kept dry
High freq losses limit the practical length of the line

Question 11

What are 2 types of waveguides in use today.

Answer 11

Cylindrical

Rectangular

Question 12

What are 3 types of line losses associated with transmission lines?

Answer 12

Copper
Dielectric
Radiation

Question 13

Losses caused by skin effect & the I 2 R (power) loss are classified as what type of loss.

Answer 13

Copper losses

Question 14

What type of losses cause the dielectric material between the conductors to be heated?

Answer 14

Dielectric loss

Question 15

What are 2 of the 3 physical factors that determine the values of capacitance & resistance of a transmission line.

Answer 15

Type of line used
Dielectric in the line
Length of line

Question 16

A transmission line is said to have distributed constants of inductance, capacitance, & resistance along the line.

What units of measurements are used to express these constants

Answer 16

Inductance is expressed in microhenrys per unit length.

Capacitance picofarads per unit length.

Resistance is expressed in ohms per unit length

Question 17

Describe the leakage current in an expression line.

What unit is it expressed.

Answer 17

The small amount of current that flows through the dielectric between 2 wires of a transmission line.

Expressed in micromhos per unit length

Question 18

All power sent through a transmission line from a transmitter can be transferred to an antenna under what optimum conditions?

Answer 18

When the characteristic impedance of the transmission line & the load impedance are equal.

Question 19

What symbol is used to designate the characteristic impedance of a line.

What 2 variables doe it compare?

Answer 19

Z0

The ratio if E to I at every point along the line.