On 8/3/2011 12:50 PM, John F. wrote:
> Roger.....
>
> As you know, an inverted vee for a given freq is a balanced antenna with
> essentially equal current and voltage on both legs. Grounding one leg
> at or near the feedpoint will destroy that balance. Depending on the
> height and freq, it will be omni-directional or directional broadside to
> the legs. The angle of radiation is also dependent upon the height/freq
> and angle between the legs (ideally a minimum of 110 degrees).
>
> Using a balun ( I assume 1:1/ choke type) may or may not be beneficial,
I run current baluns on almost everything now days and the feedlines
have their shields grounded to the tower top and bottom. With an
inverted V the ground is quite close to the choke and the antenna
connects to the current balun within just a few inches. The baluns are
designed using Jim Brown's tutorial (watch out for line wrap.)
http://www.audiosystemsgroup.com/RFI-Ham.pdf
BTW for the center fed, sloping, fan dipole on 75, I have one choke
balun at the feed point and one where the feed line reaches the tower.
I've not run into any apparent problems.
73
Roger (K8RI)
> depending on how close the legs are to the tower and the ground. It may
> help keep RF from flowing on the outside of the coax. I'd just put it
> up and see what happens.
>
> GL, and 73
>
> John W4II
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