Page 9 - GEN-radio 2025 - færdig_Neat
P. 9
13.1.1.1 Speed of Propagation ................................................... 97
13.1.1.2 Wavelength .................................................................. 97
13.2 Frequency Units .................................................................................... 98
13.3 Radio Frequency Bands .......................................................................... 98
13.3.1 Frequency Spectrum .................................................................. 98
13.3.2 VHF Frequence Spread ............................................................... 99
13.3.3 VHF Frequence Separation ......................................................... 99
13.3.3.1 Sidebands and Bandwidth ............................................ 99
13.3.3.2 VHF Bandwidth ............................................................ 99
13.4 VHF Propagation Characteristics ............................................................ 99
13.4.1 Propagation Paths ...................................................................... 99
13.4.1.1 Direct and Ground-reflected Waves .............................. 100
13.4.2 Factors Affecting VHF Propagation .............................................. 101
13.4.2.1 Attenuation.................................................................. 101
13.4.2.2 Refraction .................................................................... 101
13.4.3 Effective Range of VHF ................................................................ 101
13.4.3.1 Line of Sight Range ....................................................... 101
13.5 Freak Propagation ................................................................................. 102
13.5.1 Duct Propagation ........................................................................ 103
13.5.2 Scatter Propagation .................................................................... 103
GEN radio 2025 - Midtjysk Flyveskole 9
