[Elecraft] Inverted L for 160 meters

Jim Brown jim at audiosystemsgroup.com
Wed Aug 26 13:42:51 EDT 2020


On 8/26/2020 10:07 AM, David Gilbert wrote:
> Radiation angle for a vertical antenna is much more a function of the 
> ground conductivity out several wavelengths than it has to do with the 
> current balance in the radials.

Right, but N6LF has shown that current balance in radials, especially 
elevated ones, minimizes ground losses.  Yes, elevated radials can be 
modeled in less capable versions of NEC. All of this is addressed in my 
slides.

In all cases, the model must use soil conductivity representative of the 
QTH. This is selected from a menu. Soil conductivity affects us two 
ways. First, losses underneath the antenna. Better radial/counterpoise 
systems can reduce this a lot. Second, loss in the far field, over which 
we have no control, and those losses can vary a lot if soil varies a lot 
in different directions. For example, a vertical on a beach has much 
less far field loss, and much more energy at low angles, in the 
direction of the water and much more far field loss and higher angle 
energy than in directions over land.

73, Jim K9YC


More information about the Elecraft mailing list