lhwill at verizon.net
Sun Dec 31 09:22:21 EST 2006
A dipole is only 73 ohms in free space away from ground etc. A
typical low antenna such as we hams might use often is 50 ohms or
even lower. The various antenna handbooks have a lot of info on this.
A 1/4 wave vertical series fed monopole over perfect ground is also
about 37 ohms. Typically the ones I have measured at broadcast freqs
usually have some reactance when put over a 120 radial ground screen.
At 11:45 PM 12/30/2006, you wrote:
>The more I read, the confusder I get.
>If a half wave dipole has a center feedpoint impedance of 73 ohms,
>why am I using 50 ohm coax.
>I just put my new EZ hang to use today and discovered that my coax
>is not long enough to take advantage of the much higher ends and is
>pulling the center down.
>I was going to buy a roll of RG8X but then learned that RG58U is
>good to over 430W so I might as well stick with this as weight is an issue.
>In the process of hunting up a source for coax I stumbled into this
>quandary. Every source I look at says 73 ohms for a dipole.
>What am I missing?
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