Many hams also use scanners to listen to local public safety agencies, airport activity, at the race track, or even to ham channels. Like ham radio, scanning has a lingo all its own, some of which overlaps a bit with ours. This puzzle dabbles a bit in the scanning world - can you sync up and track the clues?

Across

1. Distance between channels
6. W7 state with a trail named after it
10. Certification for awards (abbr.)
11. Unruly groups, such as in a pileup
12. Electromagnetic (abbr.)
14. Standard time (abbr.)
16. Manufacturer of digital voice modem
18. System of traffic nets (abbr.)
20. Vertical angle (abbr.)
21. Subaudible tone system (abbr.)
23. Trademarked synonym for 21 Across (abbr.)
24. Makes a nice battery with Lithium
25. Type of display (abbr.)
27. User (abbr.)
29. Often confused with FM (abbr.)
30. Next to
32. Makes a ducky antenna
34. The switch that speaks (abbr.)
35. Shortwave band (abbr.)
37. Surprised laughter
39. Large inland sea between UN and UJ
41. FET control element
42. Add 'E' to get a big solar disturbance
43. Equipment
44. Operate while moving
46. Communicate on two frequencies
48. Largest land continent (abbr.)
49. First digital logic family (abbr.)
50. Greek letter meaning 'micro'
52. Digital squelch system (abbr.)
54. Opposite of WBFM (abbr.)
56. Collection or team
59. Add 'IO' to get Old Macdonald
60. Collector current (abbr.)
61. Radio regulators (abbr.)
63. CW prosign for 'and'
64. Leave out
66. Standard for digital characters (abbr.)
68. Narrow filter
70. The band below AM broadcast (abbr.)
71. Add 'U' to get a coffee pot
72. Often confused with NH (abbr.)
73. The set of test questions
74. Antennas aligned vertically

Down

1. Circuit that mutes receiver audio
2. Keeps volume constant (abbr.)
3. Unit of volume (abbr.)
4. Really mad
5. Big brother to FRS
6. Official station that relays bulletins
7. Russian satellite prefix
8. Older term for 14 Across
9. One of the compass points
13. Listen to
15. Gentle attention (abbr.)
17. The watery continent (abbr.)
18. Postal code for VO1
19. Communicate on one frequency
22. Replacements (abbr.)
23. Increases sensitivity of a receiver
26. Logarithmic ratio (abbr.)
28. These carry information in an AM signal (abbr.)
31. Parasitic beams
32. Speed of digital bit transmission
33. Repeated roger (abbr.)
36. Swings with 'to'
38. Intelligent computer in 2001
40. Length of life
42. See you again (CW abbr.)
44. Type of modulation
45. Fixed station
46. Two-tone signalling standard
47. Periodic type of antenna
49. Frequencies higher than audio (abbr.)
50. Metal that shields magnetic fields
51. Radio path to the satellite
53. Italian goodbye
54. Highest energy rechargeable battery
55. Interference from broadcast stations (abbr.)
57. Start again
58. Signal source (abbr.)
62. Your radio ID
64. Base-8 (abbr.)
65. Binary base
67. Postage coupon (abbr.)
68. Where Lewis and Clark spent the winter (abbr.)
69. Idiot box (abbr.)