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## Topband: Inverted V antenna!

 To: Topband: Inverted V antenna! k6se@juno.com (k6se@juno.com) Mon, 6 May 2002 21:34:21 -0700
 ```Don, W7DD wrote: "I just modeled an inverted V antenna on EZNEC. The apex height is at 87'(for an 89' tower), ends are 2 feet above ground, ground conductivity is 1.5s/m, dielectric constant is 13 and 1/4 wave elements are 127.6' long/side. Frequency was 1.85mhz. The ground description is for Tucson,Az. "The results show that it is a BETTER VERTICAL than horizontal by 3dbi at a elevation angle of 20 degrees to the horizon. This is off the ends. Horizontal is broadside." ========== I used EZNEC v3.0 to model the same antenna that Don describes. Because the antenna is so low to the ground, I used the "high accuracy" method to do the plots. Using 1.5 s/m, the horizontal component is down 4.45 dB from the vertical component at 20 degrees elevation. I immediately suspected that Don's description of the soil conductivity in Tucson was wrong (1.5 s/m is not too much worse than sea water, which is 5 s/m). So I played around with the soil conductivity until I got the 3.0 dB difference that Don mentioned, which turned out to be 0.0076 s/m (I left the dielectric constant at 13). With 127.6' of #12 AWG wire on each leg of the antenna, the resonant frequency is 1.876 MHz, so I made all plots at that frequency. The gain of the horizontal compont broadside to the antenna is -4.76 dBi. The gain of the vertical component off of the ends of the antenna is -1.76 dBi, which is 3.52 dB less than a grounded vertical antenna over the same soil with a good ground radial system. 73, de Earl, K6SE ```
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