Dan and all... I am in the middle of constructing 4-squares for 160m and 80m. One element of each array is up and operating. A decision must be made concerning the layout of Teflon-insulated radial wire and whether to run a bus wire/strap at the intersection of overlapping radials. It may not seem like it, but it's a lot of extra work and I just want to ensure the effort is worth the result. Cost of the extra wire is not the issue.
What I am trying to determine is how much detrimental wire-to-wire coupling occurs when *insulated* radial wire cross and its effect on: (1) cancellation of radial current; (2) pattern; and (3) F/B performance. I have researched Laport's material, and find nothing that compares multi-tower array performance when using insulated radial wire versus uninsulated wire when using a bus wire at the radial overlap points. Since his worked in the 1950s mostly focused on directional broadcast tower arrays -- and the use of heavy-gauge wire, possibly insulated radial wire wasn't considered because of long-term insulation decomposition that one day results in electrical contact between overlapping radials. So, can anyone point me to results that show a modeled comparison between the two types of radial system layouts and even better, actual measured field strength results? I do have a NEC 4.2 license, 4Nec2, and just recently purchased EZNEC Pro/4 and AutoEZ. Ultimately, I will run my own analysis, but it always helps to look at someone else's data to ensure ground system modeling is set up correctly. Paul, W9AC -----Original Message----- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Dan Maguire via Topband Sent: Thursday, February 1, 2018 2:02 AM To: topband@contesting.com Subject: Re: Topband: Adding a parasitic reflector to a vertical For AutoEZ users: A model similar to the parasitic array that Tim described is available on this page: http://ac6la.com/aecollection8.html In the first section of that page, scroll down to topic "Parasitic Elements" and then look for the text "For a vertical parasitic example I chose a model described by N6LF ...". The sample model is for 80m but everything is controlled via variables and there are instructions (within the model itself) on how to scale for other bands. Links to several references are also included on the above page. Dan, AC6LA _________________ Topband Reflector Archives - http://www.contesting.com/_topband _________________ Topband Reflector Archives - http://www.contesting.com/_topband