Figure out how to do that for a small lot backyard in an old European village with 900 year old homes.
73, Guy. On Wed, Oct 3, 2012 at 3:59 AM, Jim Brown <[email protected]> wrote: > On 10/3/2012 12:35 AM, Bob Kupps wrote: > >> "It is impossible to make a direct measurement of ground characteristics". >> > > Horsepucky. Now, what IS difficult is to make a direct measurement to > great depth! But N6LF has shown a simple method to measure to the depth of > whatever length of rod you are willing (and able) to drive. > > The "slope of the decay of field strength" method is a very good method > for frequencies for which good data is published, but to get good data > you've got to take a lot of data points along a radial from the test > transmitter site. More than fifty years ago, I worked for a broadcast > consultant who did that as part of his applications for new licenses in a > band that had been full for 30 years. ) My job was to plot his data and > extract the conductivity data. > > You could, for example, use this method with a local broadcaster operating > near the high end of the AM broadcast band. BUT -- you need calibrated > instrumentation to get accurate field strength measurements, and you need > to make a LOT of measurements at a chosen azimuth that covers the area of > interest along a line drawn from the transmitter to and past the area of > interest. You must then plot that data of field strength vs. distance, > then compare it to FCC curves for that operating frequency, matching the > SLOPE of your data to one of the several families of curves in the FCC data. > > This is NOT a trivial exercise! > > 73, Jim K9YC > > ______________________________**_________________ > UR RST IS ... ... ..9 QSB QSB - hw? BK > _______________________________________________ UR RST IS ... ... ..9 QSB QSB - hw? BK
