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## Re: [Antennaware] 160 meter 3/8 wire, steel or copper

 To: "OZ1AXG Flam" Re: [Antennaware] 160 meter 3/8 wire, steel or copper Terry Conboy Wed, 24 Sep 2008 12:11:17 -0700 mailto:antennaware@contesting.com>
 ```At 11:21 AM 2008-09-24, OZ1AXG Flam wrote: >A question about wire ... > >I have constructed a 3/8 for 160 meter. I use the tower to support the >antenna. It runs 22 meter vertically and then (horisontal for 24,5 meters >(i.e. total 46.5 meter). distance from tower is 1 meter. >A the base of the antenna it is feed with a serial capacitor of 430 pF (a >330 in parallel with a 100pF : both door noob). > >Ground is a combination of 4 ground rods and wire (space is limited). Best >swr @ 1860 Khz is 1:1.4. 1:2 bandwidth is app 80KHz. A noise bridse have >shown impedans around 70+j1. > >Currently the wire is 1.5mm stainless steel wire. > >How much would the antenna be improved if i substitute the SS wire with with >1.5mm braided copper wire? >I guess the seial capacitor would change as well ? any idea how much ? > >Antennewire i use ( steel 40050 and copper: 40051): >http://www.wimo.de/cgi-bin/verteiler.pl?url=wireantennas_e.html > >-- >OZ1AXG Flam Flam, I modeled this with EZNEC (without the tower) and assumed the 1.5 mm diameter stainless steel wire has a resistivity of 7.2 e-7 ohm-m and relative permeability of 1.02. I estimated about 20 ohms of ground loss resistance. Here's what happens at 1860 kHz: Cu G=-0.43 dBi Z=52.6 -j 46.6 SWRmin=1.13 at 1922 kHz BW=97 kHz (50 ohm SWR 2:1) SS G=-1.48 dBi Z=68 -j 36.2 SWRmin=1.44 at 1907 kHz BW=90 kHz The adjacent tower will modify these values depending on where it is resonant, cross section, etc. With copper, you should get about 1 dB more signal, a better match to 50 ohms, and resonance moved up about 15 kHz. Adding another 27 pF in parallel (457 pF total) should restore the resonant point. 73, Terry N6RY _______________________________________________ Antennaware mailing list Antennaware@contesting.com http://lists.contesting.com/mailman/listinfo/antennaware ```
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