Topband: phasing line lengths for phased verticals

[Herb Schoenbohm]

Just double the length of the phasing lines and then they will reach.


Herb, KV4FZ



On 11/17/2012 10:42 PM, DALE LONG wrote:
> 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 at subich.com>
> To: topband at 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 at contesting.com
>>
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