As a reference, I have an 80M 4-sq with 5 elevated radials at each feed point and use a Comtek box. The radials were 1/4 wave. The pattern was terrible. Very little F/S and F/B. I measured the current in each radial. It was all over the place. I followed N6LF's info and cut the radials to 42'. I connected all 5 radials together at each feed point then added a small coil between the 5 radials and the coax shield to retune the elements. Now the current is very close with each radial and the F/S and F/B is much, much better. Read N6LF's stuff and take a look at balancing elevated radials if you go that route. 73, N2TK, Tony
-----Original Message----- From: [email protected] <[email protected]> On Behalf Of David Gilbert Sent: Wednesday, August 26, 2020 2:11 PM To: [email protected] Subject: Re: [Elecraft] Inverted L for 160 meters Yes, certainly current balance would minimize ground losses. I hadn't thought much about it before, but I guess it's kind of intuitive in that it's analogous to lower return resistance losses due to better use of parallel ground paths. 73, Dave AB7E On 8/26/2020 10:42 AM, Jim Brown wrote: > 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 ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
