Joe...I was wrong in my post. My verticals are 1/2 wave apart on 80m, which is
the same as 1/4 wave on 160.
After writing my message, I went back and added the 66' for clarity, and should
have been 132'
You are correct, using RG8X with velocity factor of .78, the phasing lines are
about 53.5' and there are two of them, making them a too short to reach the 132'
I really DO have 80m verticals that are 1/2 wave apart. (incidentally I share
the radial fields with the 160m antennas which are 1/4 wave apart)
So the question remains, how to properly feed phased verticals that are
physically 1/2 wave apart
73
Dale
________________________________
From: "Joe Subich, W4TV" <lists@subich.com>
To: topband@contesting.com
Sent: Saturday, November 17, 2012 7:18 PM
Subject: Re: Topband: phasing line lengths for phased verticals
> > 1. for 80m phased verticals that are 1/2 wave apart (66 feet),
That is 1/4 wave separation - not half-wave. One half wave on 80 is
roughly 139 feet (984/3.55/2 = 138.6 feet).
Since you are using 1/4 wave spacing and a PVS-2 (which is a quadrature
device if I remember correctly), two /14 wave cables (about 54' each
when the velocity factor for foam is included) should *easily* reach
the midpoint of the array.
73,
... Joe, W4TV
On 11/17/2012 6:56 PM, DALE LONG wrote:
> Until recently, I had phased verticals on both 80m and 160m and lots of
> beverages. (this was in a woods, and not my property) Then the loggers came
> and destroyed all.
>
> In addition to the antennas, the phasing lines were torn up, and broken and
> needed replacement. For 160m I use the Christman method with .71 and .84
> wavelength lines. For 80m I use a Comtek PVS-2 controller.
>
>
> In replacing the 80m phasing lines today I made a stupid mistake, I dont know
> what I was thinking, but I carefully measured and soldered two identical 1/4
> wave lengths of new coax. I tested them on my AIM 4170 and they were nearly
> identical, exactly on the design frequency. Then I went to install them and
> guess what...of course they were too short. I have worked with phased
> verticals before and I know that you often need to use 3/4 wave phasing
> lines, but I was too intent on measuring and soldering and making the repairs.
>
> So now I have two questions.
>
> 1. for 80m phased verticals that are 1/2 wave apart (66 feet), what will be
> the pattern? It's not the same as 1/4 wave spacing, so what really is
> happening?
>
> 2. what is the best length of phasing line to use. Should I use 3/4 wave
> phasing lines? Should I avoid using 1/2 wave phasing lines?
>
> Thanks
>
> Dale - N3BNA
> _______________________________________________
> Topband reflector - topband@contesting.com
>
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