TC 9-64 _________________________________________________________________________
Principles of Transmission Lines
1. What connecting link is used to transfer energy from a radio transmitter to its antenna
located on the mast of a ship?
2. What terms are used to describe the end of the transmission line that is connected to a
3. What terms are used to describe the end of the transmission line that is connected to an
4. List the five types of transmission lines in use today.
5. Name two of the three described uses of a two-wire open line.
6. What are the two primary disadvantages of a two-wire open line?
7. What type of transmission line is often used to connect a television set to its antenna?
8. What is the primary advantage of the shielded pair?
9. What are the two types of coaxial lines in use today?
10. What is the chief advantage of the air coaxial line?
11. List the three disadvantages of the air coaxial line.
12. List the two common types of waveguides in use today.
13. What are the three types of line losses associated with transmission lines?
14. Losses caused by skin effect and the I2R (power) loss are classified as what type of loss?
15. What types of losses cause the dielectric material between the conductors to be heated?
16. What must the physical length of a transmission line be if it will be operated at 15,000,000
Hz? Use the formula:
17. What are two of the three physical factors that determine the values of capacitance and
resistance along the line. What units of measurement are used to express these constants?
19. Describe the leakage current in a transmission line and in what unit it is expressed.
20. All the power sent down a transmission line from a transmitter can be transferred to an
antenna under what optimum conditions?
21. What symbol is used to designate the characteristic impedance of a line, and what two
variables does it compare?
22. What is the range of the characteristic impedance of lines used in actual practice?
23. Two types of waves are formed on a transmission line. What names are given to these waves?
24. In figure 3-27, which waveforms on the left have a resultant wave of zero, and what is
indicated by these waves?