TC 9-64 _________________________________________________________________________
24. What is the difference in the amount of impedance between a three-wire dipole and a simple
center-fed dipole?
25. Which has a wider frequency range, a simple dipole or a folded dipole?
26. What is the purpose of antenna stubs?
27. What is the primary difference between the major and minor lobes of a radiation pattern?
28. What is the maximum number of elements ordinarily used in a collinear array?
29. Why is the number of elements used in a collinear array limited?
30. How can the frequency range of a collinear array be increased?
31. How is directivity of a collinear array affected when the number of elements is increased?
32. What is the primary cause of broadside arrays losing efficiency when not operating at their
designed frequency?
33. When more than two elements are used in a broadside array, how are the elements
arranged?
34. As the spacing between elements in a broadside array increases, what is the effect on the
major lobes?
35. What are some disadvantages of the end-fire array?
36. Where does the major lobe in the end-fire array occur?
37. To maintain the required balance of phase relationships and critical feeding, how must the
end-fire array be constructed?
38. What two factors determine the directivity pattern of the parasitic array?
39. What two main advantages of a parasitic array can be obtained by combining a reflector and
a director with the driven element?
40. The parasitic array can be rotated to receive or transmit in different directions. What is the
name given to such an antenna?
41. What are the disadvantages of the parasitic array?
42. What is the advantage of adding parasitic elements to a yagi array?
43. The yagi antenna is an example of what type of array?
44. To radiate power efficiently, a long-wire antenna must have what minimum overall length?
45. What is another name for the Beverage antenna?
47. What is the main disadvantage of the rhombic antenna?
48. What is the primary reason for the development of the turnstile antenna?
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