[600MRG] EIRP

[Rudy Severns]

Frank, XHA, asked a question on how you go from EIRP to radiated power.
Neil (XSV) has just made available the calculation in spreadsheet format
which is based on a note from Fritz Raab.  When you go from an isotropic
(equal radiation in all directions)  radiator to a vertical over ideal
ground you pick up a factor of two (+3dB) from ground reflection and a
factor of 1.5 (+1.77 dB) from the directivity of a typical short vertical.
2 X 1.5 = 3 and 5W/3 =1.67W.   Over ideal ground a short vertical radiating
1.7W will have the same field strength, at a given distance, as 5W from an
isotropic at the same distance.  

 

73, Rudy