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## RE: [TowerTalk] 80m 4Square Dipole VSWR question

 To: "'Paul Playford'" ,"'towertalk'" RE: [TowerTalk] 80m 4Square Dipole VSWR question "Joe Subich, K4IK" Wed, 17 Nov 2004 15:57:57 -0500
 ``` > From: Paul Playford > > Assuming that the phase shifting box was designed to drive a > ground plane array this would require the 0 degree port match > 165 ohms, the 90d port match 82 ohms (two elements in parallel) > and the 180d port match 165 ohms. Except the 0 degree port and the 180 degree port are actually connected in parallel (the 180 degree port is connected to the zero degree port through a phase reversal transformer/un-un). Thus, you have the quadrature (90 degree) port and the in-phase port each seeing 82 Ohms ... which when combined result in a nominal input impedance of 41 Ohms for the "box." Of course, all of that does not consider the mutual coupling among the elements of a four square or ground losses! However, a four square constructed of verticals (over perfect ground) that were adjusted for j0 in isolation and spaced 1/4 wave on a side would show widely differing impedances for the leading, lagging and side elements. AO shows something on the order of: Leading element (1) 67.2 +j53 Side elements (2&3) 37.3 -j19.4 Lagging element (4) -1.5 -j12.9 Given the wild mismatches, it would be interesting to see some measurements of actual current magnitude and phase in a "real world" four square being fed with a Comtek style box. 73, ... Joe, K4IK _______________________________________________ See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions and ask for Sherman, W2FLA. _______________________________________________ TowerTalk mailing list TowerTalk@contesting.com http://lists.contesting.com/mailman/listinfo/towertalk ```
 Current Thread [TowerTalk] 80m 4Square Dipole VSWR question, D. Rodman, MD Re: [TowerTalk] 80m 4Square Dipole VSWR question, Tom Rauch RE: [TowerTalk] 80m 4Square Dipole VSWR question, Paul Playford RE: [TowerTalk] 80m 4Square Dipole VSWR question, Joe Subich, K4IK <= Re: [TowerTalk] 80m 4Square Dipole VSWR question, Tom Rauch Re: [TowerTalk] 80m 4Square Dipole VSWR question, Yo3ctk Re: [TowerTalk] 80m 4Square Comtek box, Jan Erik Holm Re: [TowerTalk] 80m 4Square Comtek box, Yo3ctk Re: [TowerTalk] 80m 4Square Comtek box, Jim Lux Re: [TowerTalk] 80m 4Square Comtek box, R. Kevin Stover Re: [TowerTalk] 80m 4Square Comtek box, Yo3ctk Re: [TowerTalk] 80m 4Square Comtek box, Jan Erik Holm Re: [TowerTalk] 80m 4Square Comtek box, Al Baker Re: [TowerTalk] 80m 4Square Comtek box, Jan Erik Holm