[Top] [All Lists]

Re: [TowerTalk] cutting phasing lines

To: "Tower and HF antenna construction topics." <>
Subject: Re: [TowerTalk] cutting phasing lines
From: "Jack/W6NF" <>
Reply-to: "Tower and HF antenna construction topics." <>
Date: Sun, 11 Apr 2010 16:30:56 -0700
List-post: <">>
I just put a 2-element 40-meter vertical array in service using the
Christman feed, cut for 7060kHz. I used my VA-1 to cut the 4 lines to
1/4-wave, measured the lines, calculated the length necessary to get 71 and
84 degrees and trimmed accordingly. There is a little waste but it was worth
it for the sake of simplicity.

I have had the antennas in service for a couple of weeks and find about 20db
of f/b ratio, which is in accordance with the EZNEC calculations I did
before proceeding. My "common point" complex impedance is close to the
predicted value but I have not yet built a matching network to bring it to
near 50 j0. The tuner in my IC-746 handles the present impedance well.

The antennas are on a 75/255 azimuth, primarily to reduce signals from the
US midwest and east coast when working the Pacific/VK/ZL. It seems to work
pretty well in spite of the drawbacks I've heard about this feed system.

On Sun, Apr 11, 2010 at 3:18 PM, <> wrote:

> Gdy all, my Q is I need to cut phasing lines for 7.050 Mhz of 84
> degrees es 71 degrees! ok So far,  now 360 degrees = 1 wave length, so
> 0.5 wavelrngth (=180 degrees) would be 468/freq /vf es / by 180 would
> be 1 degree so x by required degrees  eg 84 es 71  ok ! so now how do
> I convert 84 es 71 degrees to a frequency so I can cut the lines WITH
> my antenna bridge rx vector analyst autek VA1?? OR AM i  WAY OFF IN MY
> THINKING!! 73 es tnx Al vk3pa
> _______________________________________________
> _______________________________________________
> TowerTalk mailing list

Jack, W6NF
Silver Springs, NV

TowerTalk mailing list

<Prev in Thread] Current Thread [Next in Thread>