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## Re: [TowerTalk] Shunt Fed tower question

 To: RLVZ@aol.com, towertalk@contesting.com Re: [TowerTalk] Shunt Fed tower question TexasRF@aol.com Tue, 17 Jan 2012 18:57:01 -0500 (EST) mailto:towertalk@contesting.com>
 ```Hello Dick, your numbers are telling you that the feed point is already inductive. A series capacitance of 344 ohms should cancel the inductance and result in a very low vswr at the frequency of your test. That comes out to be about 250 pF. The voltage rating will be related to the rf power used. At 1500w, there will be 5.4 amps through the capacitor and that would produce an rf voltage of 1865 volts rms. Peak voltage will be about 2650 so a well rated capacitor would be needed. If made adjustable, the voltage will go well above that number while tuning. Sounds like a nice antenna! 73, Gerald K5GW In a message dated 1/17/2012 5:35:09 P.M. Central Standard Time, RLVZ@aol.com writes: Hi Guys, I'm shunt feeding a 90' aluminum tower for 160-meters. . I found the 50 ohm tap point on the tower and have the shunt wire connected to the tower at that point. At the base of the Shunt wire I'm measuring the following: -Rs = 51 ohms. -Xs = 344. -Q = 6 -Ls = 30.1 uH. Please advise what I need to add to this circuit... such as: a 30uH inductor? If a 30uH inductor can I easily make one, such as: X turns of #10 wire with a 3" diameter? Thanks, Dick _______________________________________________ _______________________________________________ TowerTalk mailing list TowerTalk@contesting.com http://lists.contesting.com/mailman/listinfo/towertalk _______________________________________________ _______________________________________________ TowerTalk mailing list TowerTalk@contesting.com http://lists.contesting.com/mailman/listinfo/towertalk ```
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