My Minnebar 9 / 2014 talk about RTL-SDR Video of talk at https://www.youtube.com/watch?v=N2u3Qu1dhAs

1. RTL-SDR &
Software-Defined
Radios

2. About Me
@tcollen
tony@halogenlabs.com

3. I'm a radio nerd.

4. N0RUA

7. 1/5/2013 / ZD7FT / St. Helena Island (6,866 mi)

8. 2/23/2014 / RX0AK / Asiatic Russia / 5,460 mi

9. Public Service

10. Cool experiments

12. It's all around us!

13. It's all around us!
• AM/FM audio broadcast

14. It's all around us!
• AM/FM audio broadcast
• TV broadcast

15. It's all around us!
• AM/FM audio broadcast
• TV broadcast
• Cell phones, wifi

16. It's all around us!
• AM/FM audio broadcast
• TV broadcast
• Cell phones, wifi
• Bluetooth, etc.

17. It's all around us!
• AM/FM audio broadcast
• TV broadcast
• Cell phones, wifi
• Bluetooth, etc.
• But...

18. How does it work??

19. Components

20. Components
transducer

21. Components
transducer

22. Components
transducer

23. Components
transducer

24. Components
transducer
Oh yeah, the antenna
goes here.

26. Components
transducer
Electromagnetic Radiation aka!
~~~ Radio Waves ~~~

27. Direction of travel

29. Wavelength

30. Wavelength

31. Wavelength

32. Wavelength

33. Frequency

34. Hertz = Hz = Cycles per second

35. Time!
(sec)
1 2 3

36. Time!
(sec)
1 2 3
f = 1 Hz

37. Time!
(sec)
1 2 3
f = ~ 4 Hz

38. Time!
(sec)
1 2 3
Higher Frequency = Shorter Wavelength

39. A little math...
(I'M REALLY SORRY)

40. velocity
frequency
λ =

41. velocity
λ
frequency =

42. the speed of light
(c)
frequency (Hz)
λ (m) =

43. 300,000,000 m/sec
f(Hz)
λ (m) =

44. λ (m) = 300,000,000
89,300,000

45. λ (m) = 300,000,000
89,300,000
300
89.3

46. λ (m) = 300,000,000
89,300,000
300
89.3
3.35 m
~11 ft

47. 300
89.3
3.35 m
300
2400
.125 m
~11 ft ~ 4.9 in

48. 300
89.3
3.35 m
300
14.2
21.1 m
300
2400
.125 m
~11 ft~69 ft ~ 4.9 in

49. Enough of that..

50. 3 kHz - 300 GHz
Radio spectrum

51. λ = 100 km - 1 mm
Radio spectrum

56. AM Broadcast!
~ 530 - 1700 kHz
= 1170 kHz bandwidth
FM Broadcast!
87.5 - 108 MHz
= 20.5 MHz bandwidth
Wi-Fi/etc!
2.4 - 2.5 GHz
= 100 MHz bandwidth

57. Modulation

58. = encoding
information
in a signal

62. beeeeeep beep beeeeeep

63. K
beeeeeep beep beeeeeep

65. AM

66. FM

67. Propagation

68. Line of Sight

69. Groundwave

70. Skywave

71. Ionosphere
60 - 500 km altitude

72. Ionosphere
Day
"D" Layer

73. Ionosphere
Day
"E" Layer

74. Ionosphere
Day
"F1" Layer

75. Ionosphere
Day
"F2" Layer

76. Ionosphere
Day

77. Ionosphere
Day

78. Ionosphere
F Layer
E Layer
Night

79. F Layer
E Layer

80. F Layer
E Layer

81. F Layer
E Layer
Maximum Usable Frequency (MUF)

82. F Layer
E Layer

83. skip distance

84. Auroral

85. Meteor Scatter

86. What's out
there?

87. WTF's out there?
HF/Shortwave

88. WTF's out there?
HF/Shortwave
• Broadcasters (AM / Shortwave)

89. WTF's out there?
HF/Shortwave
• Broadcasters (AM / Shortwave)
• Hams

90. WTF's out there?
HF/Shortwave
• Broadcasters (AM / Shortwave)
• Hams
• Gov't Agencies (US or otherwise)

91. WTF's out there?
HF/Shortwave
• Broadcasters (AM / Shortwave)
• Hams
• Gov't Agencies (US or otherwise)
• WEFAX, other data & telemetry

92. WTF's out there?
HF/Shortwave
• Broadcasters (AM / Shortwave)
• Hams
• Gov't Agencies (US or otherwise)
• WEFAX, other data & telemetry
• "Numbers stations"

93. WTF's out there?
HF/Shortwave
• Broadcasters (AM / Shortwave)
• Hams
• Gov't Agencies (US or otherwise)
• WEFAX, other data & telemetry
• "Numbers stations"
• Pirates

94. WTF's out there?
HF/Shortwave
• Broadcasters (AM / Shortwave)
• Hams
• Gov't Agencies (US or otherwise)
• WEFAX, other data & telemetry
• "Numbers stations"
• Pirates
• Lots more!

96. WTF's out there?
VHF/UHF & beyond

97. WTF's out there?
VHF/UHF & beyond
• FM Broadcast

98. WTF's out there?
VHF/UHF & beyond
• FM Broadcast
• Hams

99. WTF's out there?
VHF/UHF & beyond
• FM Broadcast
• Hams
• Fire/Police/EMC/Mall Cops

100. WTF's out there?
VHF/UHF & beyond
• FM Broadcast
• Hams
• Fire/Police/EMC/Mall Cops
• Airport/ATC/ADS-B

101. WTF's out there?
VHF/UHF & beyond
• FM Broadcast
• Hams
• Fire/Police/EMC/Mall Cops
• Airport/ATC/ADS-B
• Pagers & other text (Taxi Dispatch)

102. WTF's out there?
VHF/UHF & beyond
• FM Broadcast
• Hams
• Fire/Police/EMC/Mall Cops
• Airport/ATC/ADS-B
• Pagers & other text (Taxi Dispatch)
• Baby monitors

103. WTF's out there?
VHF/UHF & beyond
• FM Broadcast
• Hams
• Fire/Police/EMC/Mall Cops
• Airport/ATC/ADS-B
• Pagers & other text (Taxi Dispatch)
• Baby monitors
• FUN stuff in the 433 MHz band (unlicensed)

105. Software-
Defined
Radios

108. RTL-SDR

114. So what?

115. So what?
• Hobby

116. So what?
• Hobby
• Experimentation

117. So what?
• Hobby
• Experimentation
• Public Service

118. So what?
• Hobby
• Experimentation
• Public Service
• Cool Gear ;)

119. Actual stuff you can do

120. Detecting the galactic plane with an SDR

122. rtl-sdr.com

123. Let's listen
to some radio!