[HCDX] Groundwave Propagation On SW
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[HCDX] Groundwave Propagation On SW



  Groundwave propagation distance is definitely dependent upon transmitter power, transmission mode, vertical antenna design and ground conductivity. Horizontal antennas produce virtually no ground or surface wave broadside to the antenna but they do produce some off of the ends.
  This is very general but you can expect true ground or surface wave between 300-3000 kc and more of a direct wave on HF between 3000- 30000 kc, with line of sight above 30000 kc. On VLF and LF propagation is more of a waveguide thing on the underside of the D layer.
   You might expect to see the following approximate ground or surface wave distances for given frequencies:

350 kc 400 miles
540 kc 200 miles
1800 kc 100 miles
3000 kc 60 miles
7000 kc 40 miles
28000 kc 10 miles

Over water is a totally different story. At day on the beach at Cape Canaveral, FL you can here the MF AM broadcast band 50 KW stations in New York City at an approximate distance of 1000 miles.


73,
Thomas F. Giella
Space & Atmospheric Weather Forecaster
C/S KN4LF
4208 Thackery Way
Plant City, FL, USA 33566
EL87WX

Florida Space & Atmospheric Weather Institute:
http://www.kn4lf.com/fsawi.htm
 
KN4LF Daily Solar Space Weather & Geomagnetic Data Archive:
http://www.kn4lf.com/kn4lf5.htm
 
KN4LF 160 Meter Amateur Radio Resources & More:
http://www.kn4lf.com/kn4lf.htm
 




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