1. Technician Licensing Class
Antennas
Valid July 1, 2014
Through
June 30, 2018 1

2. Amateur Radio Technician Class Element 2 Course Presentation
ELEMENT 2 SUB-ELEMENTS (Groupings)
About Ham Radio
Call Signs
Control
Mind the Rules
Tech Frequencies
Your First Radio
Going On The Air!
Repeaters
Emergency!
Weak Signal Propagation 2

3. Amateur Radio Technician Class Element 2 Course Presentation
ELEMENT 2 SUB-ELEMENTS (Groupings)
Talk to Outer Space!
Your Computer Goes Ham Digital!
Multi-Mode Radio Excitement
Run Some Interference Protection
Electrons – Go With the Flow!
It’s the Law, per Mr. Ohm!
Go Picture These!
Antennas
Feed Me with Some Good Coax!
Safety First! 3

4. Antennas Polarization is relative to the Earth’s surface
T9A3 A simple dipole mounted so the conductor is parallel to the Earth's surface is a horizontally polarized antenna.
Polarization is relative to the Earth’s surface
Horizontal or Vertical
Simple Dipole
Three element beam

5. Six Meter ½ Wavelength Dipole
Antennas
T9A10 The strongest radiation from a half-wave dipole antenna in free space is broadside to the antenna.
T9A09 The approximate length of a 6 meter 1/2-wavelength wire dipole antenna is 112 inches.
Length of vertical in feet =
_______
468
f (MHz)
112 inches
(for half-wave dipole)
Feet = 468/50 = 9.36
9.36 x 12 = inches
Six Meter ½ Wavelength Dipole

6. Antennas
T9A05 You would change a dipole antenna to make it resonant on a higher frequency by making it shorter.
T9A02 The electric field of vertical antennas is perpendicular to the Earth.
Vertical and Horizontal Polarization
H & V Polarized Antennas

7. Antennas 1.6 x 12 = 19 inches 234 _ _____ f (MHz) Feet = 234/146 = 1.6
T9A8 The approximate length of a quarter-wavelength vertical antenna for 146 MHz is 19 inches.
_ _____
234
f (MHz)
Length of vertical in feet =
(for quarter-wave dipole)
19”
(2-meters is MHz)
Feet = 234/146 = 1.6
1.6 x 12 = 19 inches
Radiation Pattern of an Antenna Changes as Height Above Ground is Varied

8. Antennas quad dish Yagi
T9A6 Directional antennas are the quad, Yagi, and dish.
T9A1 A beam antenna concentrates signals in one direction
quad
dish
Yagi
A Beam Antenna – The Yagi Antenna

9. Antennas
T8C01 Radio direction finding methods are used to locate sources of noise interference or jamming.

10. Antennas Hidden Transmitter Hunts are called Fox Hunting
T8C02 A directional antenna would be useful for a hidden transmitter hunt.
Hidden Transmitter Hunts are called Fox Hunting
All ages participate in a Fox Hunt

11. Isotropic Radiator Pattern
Antennas
T9A11 The gain of an antenna is the increase in signal strength in a specified direction when compared to a reference antenna.
T3A03 Horizontal antenna polarization is normally used for long-distance weak-signal CW and SSB contacts using the VHF and UHF bands.
Isotropic Radiator Pattern
“Gain” of an antenna

12. Antennas
T3A04 Signals could be significantly weaker if the antennas at opposite ends of a VHF or UHF line of sight radio link are not using the same polarization.

13. Antennas
T9A12 A properly mounted 5/8 wavelength antenna offers a lower angle of radiation and more gain than a ¼ wavelength antenna and usually provides improved coverage for VHF and UHF mobile service.
T9A13 A roof mounted VHF or UHF mobile antenna normally provides the most uniform radiation pattern when mounted in the center of a vehicle roof.
T9A14 A type of loading to make an antenna electrically longer is done by inserting an inductor in the radiating portion of the antenna.

14. Section Eighteen Take Aways
Words that are bold and red appear in the correct answer. 14

15. Take Aways
A simple dipole mounted so the conductor is parallel to the Earth's surface is a horizontally polarized antenna.
The radiation is strongest from a half-wave dipole antenna, in free space, broadside to the antenna.
The approximate length of a 6 meter 1/2-wavelength wire dipole antenna is 112 inches.
The approximate length of a quarter-wavelength vertical antenna for 146 MHz is 19 inches.
A directional antenna would be useful for a hidden transmitter hunt.

16. Take Aways
You would shorten a dipole antenna to make it resonant on a higher frequency.
For vertical antennas, the electric field is perpendicular to the Earth.
The quad, Yagi, and dish are all types of directional antennas.
A beam antenna is an antenna that concentrates signals in one direction.
Radio direction finding is a method used to locate sources of noise interference or jamming.

17. Take Aways
The gain of an antenna is the increase in signal strength in a specified direction when compared to a reference antenna.
Horizontal antenna polarization is normally used for long-distance weak-signal CW and SSB contacts using the VHF and UHF bands.
Signals could be significantly weaker if the antennas at opposite ends of a VHF or UHF line of sight radio link are not using the same polarization.

18. Take Aways
A properly mounted 5/8 wavelength antenna offers a lower angle of radiation and more gain than a ¼ wavelength antenna and usually provides improved coverage for VHF and UHF mobile service.
A roof mounted VHF or UHF mobile antenna normally provides the most uniform radiation pattern when mounted in the center of a vehicle roof.
A type of loading to make an antenna electrically longer is done by inserting an inductor in the radiating portion of the antenna.

19. Element 2 Technician Class Question Pool
Antennas
Valid July 1, 2014
Through
June 30, 2018

20. T9A03. Which of the following describes a simple dipole
T9A03 Which of the following describes a simple dipole mounted so the conductor is parallel to the Earth's surface?
A ground wave antenna
A horizontally polarized antenna
A rhombic antenna
A vertically polarized antenna

21. T9A10. In which direction is the radiation strongest from
T9A10 In which direction is the radiation strongest from a half-wave dipole antenna in free space?
Equally in all directions
Off the ends of the antenna
Broadside to the antenna
In the direction of the feedline

22. T9A09. What is the approximate length, in inches, of a 6
T9A09 What is the approximate length, in inches, of a 6 meter 1/2-wavelength wire dipole antenna? 6 50
112
236

23. T9A05. How would you change a dipole antenna to make
T9A05 How would you change a dipole antenna to make it resonant on a higher frequency?
Lengthen it
Insert coils in series with radiating wires
Shorten it
Add capacity hats to the ends of the radiating wires

24. T9A02 Which of the following is true regarding vertical antennas?
The magnetic field is perpendicular to the Earth
The electric field is perpendicular to the Earth
The phase is inverted
The phase is reversed

25. T9A08. What is the approximate length, in inches, of a
T9A08 What is the approximate length, in inches, of a quarter-wavelength vertical antenna for MHz?
112 50 19 12

26. T9A06 What type of antennas are the quad, Yagi, and dish?
Non-resonant antennas
Loop antennas
Directional antennas
Isotropic antennas

27. T9A01 What is a beam antenna?
An antenna built from aluminum I-beams
An omnidirectional antenna invented by Clarence Beam
An antenna that concentrates signals in one direction
An antenna that reverses the phase of received signals

28. T8C01. Which of the following methods is used to locate
T8C01 Which of the following methods is used to locate sources of noise interference or jamming?
Echolocation
Doppler radar
Radio direction finding
Phase locking

29. T8C02. Which of these items would be useful for a
T8C02 Which of these items would be useful for a hidden transmitter hunt?
Calibrated SWR meter
A directional antenna
A calibrated noise bridge
All of these choices are correct

30. T9A11 What is meant by the gain of an antenna?
The additional power that is added to the transmitter power
The additional power that is lost in the antenna when transmitting on a higher frequency
The increase in signal strength in a specified direction when compared to a reference antenna
The increase in impedance on receive or transmit compared to a reference antenna

31. T3A03. What antenna polarization is normally used for
T3A03 What antenna polarization is normally used for long-distance weak-signal CW and SSB contacts using the VHF and UHF bands?
Right-hand circular
Left-hand circular
Horizontal
Vertical

32. T3A04. What can happen if the antennas at opposite ends
T3A04 What can happen if the antennas at opposite ends of a VHF or UHF line of sight radio link are not using the same polarization?
The modulation sidebands might become inverted
Signals could be significantly weaker
Signals have an echo effect on voices
Nothing significant will happen

33. T9A12. What is a reason to use a properly mounted 5/8
T9A12 What is a reason to use a properly mounted 5/8 wavelength antenna for VHF or UHF mobile service?
It offers a lower angle of radiation and more gain than a 1/4 wavelength antenna and usually provides improved coverage
It features a very high angle of radiation and is better for communicating via a repeater
The 5/8 wavelength antenna completely eliminates distortion caused by reflected signals
The 5/8 wavelength antenna offers a 10-times power gain over a 1/4 wavelength design

34. T9A13. Why are VHF or UHF mobile antennas often
T9A13 Why are VHF or UHF mobile antennas often mounted in the center of the vehicle roof?
Roof mounts have the lowest possible SWR of any mounting configuration
Only roof mounting can guarantee a vertically polarized signal
A roof mounted antenna normally provides the most uniform radiation pattern
Roof mounted antennas are always the easiest to install

35. T9A14. Which of the following terms describes a type of
T9A14 Which of the following terms describes a type of loading when referring to an antenna?
Inserting an inductor in the radiating portion of the antenna to make it electrically longer
Inserting a resistor in the radiating portion of the antenna to make it resonant
Installing a spring at the base of the antenna to absorb the effects of collisions with other objects
Making the antenna heavier so it will resist wind effects when in motion