Transmission Lines

Question 1

What is the meaning of the term velocity factor of a transmission line?

Answer 1

The velocity of the wave on the transmission line divided by the velocity of light in a vacuum.

Question 2

What determines the velocity factor in a transmission line?

Answer 2

Dielectrics in the line.

Question 3

Nitrogen is placed in transmission lines to:

Answer 3

Prevent moisture from entering the line.

Question 4

A perfect (no loss) coaxial cable has 7 dB of reflected power when the input is 5 watts. What is the output of the transmission line?

Answer 4

1 watt

Question 5

Referred to the fundamental frequency, a shorted stub line attached to the transmission line to absorb even harmonics could have a wavelength of:

Answer 5

1/4 wavelength

Question 6

If a transmission line has a power loss of 6 dB per 100 feet, what is the power at the feed point to the antenna at the end of a 200 foot transmission line fed by a 100 watt transmitter?

Answer 6

6 watts