W8JI wrote: >At my present QTH on 40 meters, somewhere around 15 evenly spaced radials >flattened off the measured field strength improvement. Even 60 radials >would have been a waste of wire.
The number and length of equally-spaced buried radials needed for a monopole depends rather heavily on the conductivity of the earth in which they are buried, and how close the operator needs/wants to approach theoretical perfection for that system. The link below shows how loss in the r-f ground connection for 32 x 1/4-wave buried radials is a function of earth conductivity, other things equal. For earth of high conductivity the r-f loss in that radial system is less than 1 ohm, which is rather difficult to improve upon. The only reasons preventing near-perfect radiation efficiency from the antenna system are the loss in the loading coil needed to resonate the short monopole, and the low radiation resistance of a monopole of that height on that frequency. http://i62.photobucket.com/albums/h85/rfry-100/10m_Vert32Buried_Radials.jpg R. Fry _______________________________________________ UR RST IS ... ... ..9 QSB QSB - hw? BK
