"Laying on the ground" could mean anything from laying directly on dirt to top of the grass 5 cm above the dirt. That is a wide swing in VF. 73, Guy K2AV
On Tuesday, March 10, 2015, Eduardo Araujo <[email protected]> wrote: > > "A specific description from you about the ground used for radials would > be very interesting. > > 73, Guy K2AV" > > Guy and all, > Unfortunately the only data about terrain is almost > flat farm land conformed by humus and neutral PH. > > Before having the tower and just for fun, I decided to play with Rudy N6LF > measurements, against an inverted L, and to my surprise, I got extremely > similar results about shortening radials and measuring the current of each > of them at the antenna Base. Also, I did FS measurements at ground level at > about 300 mts which acompanied the increase in current at the base of the > antenna. > > Also I repeated the test of having 4 x 1/4 wave radials lying on the > ground, measuring its current and FS. Then, raising them up in 3 step up to > 85 cm from the ground and the change in FS measurement related directly > with Rudy measurements....a huge change. > > Finally a comment about "lying on the ground" that I shared with Rudy, if > you have 20 or less radials (I didn´t do it with more) and shorten them for > maximun current at the base, which in my case was accompanied by an > increase in FS, they are quite sensitive to the distance from the ground > specially the last 1 or 2 mts. What I found was that if the grass move your > radial up let say 5 cm in the last couple of meters, and the next one is > just lying on the ground, even though equal physical length will have > different currents ergo different length to both have the peak at the > antenna base. > > As the number of radials increase, the radial length increased and that > sensitivity gets smaller. > > Good dx to all.... Eddie, LU2DKT > > ------------------------------ > > > > > > > > > > > > > > _________________ Topband Reflector Archives - http://www.contesting.com/_topband
