From karinann at tampabay.rr.com Tue Nov 1 12:41:30 2016 From: karinann at tampabay.rr.com (Karin Johnson) Date: Tue, 1 Nov 2016 12:41:30 -0400 Subject: [Antennaware] Phased Verticals Message-ID: <799BE845465544A88360F80E57870EEE@karinspc> Well some progress has been made. I've ordered Low Band DXing to obtain the Complete software CD so I can be a bit more efficient in my modeling efforts. I did complete my own spreadsheet to compute the mutual and driving point Impedances for a two element setup. I agrees with some of the ON4UN Spreadsheets that someone else has sent to me. So in my own mind I am getting To feel comfortable with understanding some of the physics behind phased Vertical systems. I do have advanced degrees in Math and Engineering so I'm no novice to complex numbers and issues around designing matching networks. The esoteric things like inductive and capacitive voltage dividers used in Phasor Networks is starting to make some sense now. What sort of has me baffled a bit is that looking at what Array Solutions has Available for a triangle array Phasor, doesn't seem to take into account the Large difference in driving point impedances when switching directions. The Array Solutions triangle box only works for 50 ohm loads at each port to guarantee the phases required at each antenna port. In other words it only does the phasor portion of the antenna system, not the complex impedance matching required at each antenna. The matching networks required at each antenna will contribute a phase shift of the driving current. For example for a triangle array of three 40M verticals spaced 0.29 wavelengths, The driving point impedance calculated for direction 1 is: EL1 = 60.16 + 12.29 EL2 = 16.42 - 43.29 EL3 = 16.42 - 43.29 Elements 2 and 3 are driven with a current magnitude of 0.5 angle of +90, Element 1 is driven with a current magnitude of 1 angle of 0. The far field plot is in the Direction (or off the end) of the Element 1 direction. Elements 2 and 3 are behind Element 1. If one were to switch directions and there were matching networks at the base of Each vertical the complete matching network would have to be changed. I can't seem to get my head around a solution just yet. More research on my part Is certainly required. This is a fun project for me so far. Eventually some time early next year I like to get started building this array. I know what most folks might say just put it up and have fun but I'm the type Of person to know the physics and math behind what works and what doesn't work. Regards, Karin K3UU From karinann at tampabay.rr.com Tue Nov 1 14:56:29 2016 From: karinann at tampabay.rr.com (Karin Johnson) Date: Tue, 1 Nov 2016 14:56:29 -0400 Subject: [Antennaware] Phased Verticals In-Reply-To: <20161101133452.Horde.XxwSaDRpuJWpWiG0pGJpvtb@webmail.hiwaay.net> References: <799BE845465544A88360F80E57870EEE@karinspc> <20161101133452.Horde.XxwSaDRpuJWpWiG0pGJpvtb@webmail.hiwaay.net> Message-ID: Hi Don: At this point I am not trying to equate simulation with real world performance. Since I am not in the actual building phase just yet, the Only thing I am trying to accomplish is to understand some of the tradeoffs In the design of the phasors and matching network. Especially being able To switch directions without a totally complicated set of matching networks. The complex math and physics I can handle. It is the actual implementation in a simulated world For now that I am trying to address. I know that there will be a lot of variables when I get to the actual site build. Luckily, or not, I do have The required test equipment and patients to accomplish the required engineering to get the array working. Karin K3UU -----Original Message----- From: donroden at hiwaay.net [mailto:donroden at hiwaay.net] Sent: Tuesday, November 01, 2016 2:35 PM To: Karin Johnson Subject: Re: [Antennaware] Phased Verticals Welcome to the world of "Antenna Snake-Oil". I have been in AM Broadcast radio for 40 years, and I was always fortunate to have had a large budget for installing 120 full length radials and 120 half-sized radials and usually in great soil conductivity like swamps and wet bogs. Even then, the formulas only came " close ". So, without a flat piece of copper out to several wavelengths, real world values will float around as the seasons change Don W4DNR Quoting Karin Johnson : > Well some progress has been made. I've ordered Low Band DXing to obtain the > > > Complete software CD so I can be a bit more efficient in my modeling > efforts. > > I did complete my own spreadsheet to compute the mutual and driving point > > Impedances for a two element setup. I agrees with some of the ON4UN > > Spreadsheets that someone else has sent to me. So in my own mind I am > getting > > To feel comfortable with understanding some of the physics behind phased > > Vertical systems. I do have advanced degrees in Math and Engineering so > > I'm no novice to complex numbers and issues around designing matching > networks. > > The esoteric things like inductive and capacitive voltage dividers used in > Phasor > > Networks is starting to make some sense now. > > What sort of has me baffled a bit is that looking at what Array Solutions > has > > Available for a triangle array Phasor, doesn't seem to take into account the > > Large difference in driving point impedances when switching directions. The > > > Array Solutions triangle box only works for 50 ohm loads at each port to > guarantee > > the phases required at each antenna port. In other words it only does the > phasor > > portion of the antenna system, not the complex impedance matching required > at > > each antenna. The matching networks required at each antenna will > contribute > > a phase shift of the driving current. > > For example for a triangle array of three 40M verticals spaced 0.29 > wavelengths, > > The driving point impedance calculated for direction 1 is: > > EL1 = 60.16 + 12.29 > > EL2 = 16.42 - 43.29 > > EL3 = 16.42 - 43.29 > > Elements 2 and 3 are driven with a current magnitude of 0.5 angle of +90, > Element > > 1 is driven with a current magnitude of 1 angle of 0. The far field plot is > in the > > Direction (or off the end) of the Element 1 direction. Elements 2 and 3 are > behind > > Element 1. > > If one were to switch directions and there were matching networks at the > base of > > Each vertical the complete matching network would have to be changed. > > I can't seem to get my head around a solution just yet. More research on my > part > > Is certainly required. > > This is a fun project for me so far. > > Eventually some time early next year I like to get started building this > array. > > I know what most folks might say just put it up and have fun but I'm the > type > > Of person to know the physics and math behind what works and what doesn't > work. > > > > Regards, > > > > Karin K3UU > > _______________________________________________ > Antennaware mailing list > Antennaware at contesting.com > http://lists.contesting.com/mailman/listinfo/antennaware