To: | "Mike Waters" <mikewate@gmail.com>, "topband" <topband@contesting.com> |
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Subject: | Re: Topband: The Idiot's Guide To Bi-Directional Two-Wire BeverageConstruction... |
From: | "ZR" <zr@jeremy.mv.com> |
Date: | Thu, 13 Dec 2012 19:08:57 -0500 |
List-post: | <topband@contesting.com">mailto:topband@contesting.com> |
Which is why military telephone wire as well as old rural Copperweld pairs
are so popular;pacing is a constant and self twisting during installation is
a given.
Calculated self impedance agrees well with results and a properly constructed set of transformers with minimum C coupling give the best F/R and common mode isolation. They do exhibit a velocity factor so you cant make one as long as a single or wider spaced pair of wires. With my very poor ground conductivity rain or seasonal variations seem to have little or no effect, 2-3 ground rods and 25-30' radials establish the reference. Carl----- Original Message ----- From: "Mike Waters" <mikewate@gmail.com> To: "topband" <topband@contesting.com> Sent: Thursday, December 13, 2012 5:05 PMSubject: Re: Topband: The Idiot's Guide To Bi-Directional Two-Wire BeverageConstruction... What we have is a transmission line that carries the signal from one direction. If the spacing between the wires varies, then the impedance does. In that case, the F/B ratio can suffer. The Z ratio of the transformers at each end depends upon this impedance. http://www.w0btu.com/Beverage_antennas.html#How_far_apart 73, Mike www. On Thu, Dec 13, 2012 at 3:08 PM, Eddy Swynar <deswynar@xplornet.ca> wrote:I wonder if I might prevail upon any & all with some first-hand real-world experience as to the "criticalness" (if any) between the two wires runningthe length & span of a 2-wire bi-directional Beverage...? Just how important is a continuos pre-set distance between the wires,anyway...? And who was it that came up with the necessity of equally-spacedwire...? And how did they determine the "optimum" distance the wires...?_______________________________________________ Topband reflector - topband@contesting.com ----- No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1430 / Virus Database: 2634/5456 - Release Date: 12/13/12 _______________________________________________ Topband reflector - topband@contesting.com |
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