Jack,
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.
Larry W3LW
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?
JACK K9ACT
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