Modulation

Definitions Amplitude: “Size” Frequency: “Rate of occurrence” Phase: “Position or interval within a cycle” Modulation: “To vary amplitude, frequency, or phase”

Pure Sine Wave (146 MHz, no info) “Carrier” Pure Sine Wave (146 MHz, no info) “Magical” Voltage or Current NOT These Time or Distance

HF and VHF Carriers Voltage or Current Slow (HF, 80 m, 3 MHz) Fast (VHF, 2 m, 144 MHz) Time or Distance

Carrier/CW/AM “Carrier” Modulator or speech AM CW or OOK (BW=150 Hz)

AM vs. FM Single Audio Tone BWFM = 5 to 15 KHz

Sidebands AM SSB USB LSB DSB 3 KHz Note break in axis 28 MHz

SSB (BW = 3 KHz) Long Distance or Weak Signal 1. Two Tone Test Waveform 2. Single Tone Test Waveform: Just a pure RF sinewave offset from carrier by audio tone frequency!! Compression “Splatter” 3. This is how SSB speech sounds (tuned, AM detection, untuned) Sound clip: http://www.hamuniverse.com/ssbinformation.html Photo: http://users.tpg.com.au/users/ldbutler/Intermodulation.htm

Amateur TV Analog fast-scan NTSC Widest BW (6 MHz) 440 MHz , 75 cm

Modulation Video Demos http://hamelmer.com/Videos.html