solar  flare,  1-4 sporadic  E,  1-4,  1-11 sudden  ionospheric  disturbances  (SID),  1-11 sunspot  activity.  1-4,  1-10 sunspots  cycles,  1-11 M Matching   networks,   2-20 antenna  couplers,  2-21 antenna  tuners,  2-20 antenna  tuning,  2-21 receive  distribution  system,  2-22 P Propagation,   1-4 angle  of  incidence      1-6,  3-14 angle  of  reflection 3-14 critical  angle,  1-6 critical  frequency,  1-5,  1-11 escape  point,  1-5 fading,   1-7 frequency   diversity.   1-8 layer  density,  1-5 multipath  fading,  1-8 reflection,   1-7 refraction,   1-4 selective   fading,   1-8 skip  distance,  1-7 skip  zone,  1-7 sky  wave,  1-7 space  diversity,  1-8 R Radar  antennas,  2-23 AN/GPN-27  (ASR-8),  2-26 AN/SPN-35A,   2-29 AS-1292/TPN-8, 2-29 AS-32631SPS-49(V),   2-27 azimuth  pulse  generator  (APG),  2-27 broadside  array,  2-25 carrier-controlled   approach   (CCA),   2-29 corner  reflector,  2-24,  2-25 cylindrical   paraboloid,   2-24,   2-25 feedhorn,   2-26 focal   point,   2-23 height-finding,   2-25 horn radiator, 2-25, 2-26 OE-172/SPS-55,   2-28 orange-peel   paraboloid,   2-24,   2-25 parabolic  reflector,  2-23 paraboloid,   2-24 truncated  paraboloid,  2-24 AS-1669/SPN-35,  2-29,  2-30 RF  safety,  2-30 dielectric  heating,  2-30 radiation  warning  signs,  2-31 rf  burns,  2-30 working   aloft,   2-32 S Satellite  communications  antennas,  2-16 AN/WSC-6(V),  2-19,  2-20 Andrew  58622,  2-19 AS-2815/SRR-1,    2-16,    2-17 backplane,   2-17,   2-19 OE-82A/WSC-1(V),  2-17,  2-19 OE-82B/WSC-1(V),   2-16,   2-18 0E-82C/WSC-1(V),   2-16,   2-18 T Transmission,   1-12 absorption,   1-14 freespace  losses,  1-13 frequency   selection,   1-13 ground  reflection  losses,  1-13 lowest  usable  frequency  (luf),  1-13 maximum   usable   frequency   (muf),   1-13 optimum   working   frequency   (fot),   1-14 plane  wavefront,  2-23 wavefront,   1-13,   2-2,   2-23,   3-14 Transmission  line,  3-1 ac,  3-5 capacitance,   3-1,   3-2 characteristic   impedance   (Z₀),  3-3 coaxial   line   (flexible/rigid),   3-6,   3-7 conductance   (G),   3-1,   3-2 copper   losses   (I²R),  3-3,  3-9 current  standing-wave  ratio  (iswr),  3-6 dc,  3-4,  3-5 dielectric  losses,  3-3,  3-4,  3-9 distributed  constants,  3-1 INDEX-2