FWIW I get well over 20dB side nulls from a 2el Cushcraft clone and about
15-20dB off the rear which varies by arrival angles.
With a pair stacked the rejection is often better and beinng able to
upper/lower/both is often an eye opener.
I never had good results with a pair of verticals on 40 but they are killers
on 160 and the feed is simple coax. IMO if you have good receiving antennas
on 160/80 there is no benefit in spending extra for a fancy switching box
for just 2 antennas which "may" get you another 5dB in F/B.
Carl
KM1H
----- Original Message -----
From: "Jack/W6NF" <vhfplus@gmail.com>
To: <topband@contesting.com>
Sent: Tuesday, February 14, 2012 3:18 PM
Subject: Re: Topband: Vertical vs yagi
> On 2/14/2012 10:32 AM, Josep Torres wrote:
>> Hi all,
>>
>> I would like to hear from people that have tried or compared a 2-3
>> element vertical array vs a 2 element yagi for 40m. I don't have a yagi,
>> but I can maybe put a 2(3) element vertical array. At moment, I only have
>> a 1/4wvl dipole at 14m high. I want to improve my setup for that band.
>>
>> Sorry for the post because this is much devoted to 160, but I know many
>> guys here have tested many antenna configurations, so maybe I can have a
>> response. Thanks very much..
>>
>> Josep
>> EA6BF
>>
>>
>>
>>
>> _______________________________________________
>> UR RST IS ... ... ..9 QSB QSB - hw? BK
>>
> Hi, Josep:
>
> Given the simplicity and minimal expense, the 2 element vertical
> performs well.
>
> Before being able to afford the Comtek 4-square phasing system last year
> I had a 2-element 40-meter array up and in use for about 5 years. It was
> a simple system using coax phasing lines (Christman feed, if I recall
> correctly) and, even in light of some of the negative comments about
> this system, it worked very well for me.
>
> In my location (northern Nevada) the most useful aspect of the antenna,
> with the elements oriented at 75/255 degrees, was the ability to
> substantially null east coast QRM when working DX from The Pacific and
> Asia. My null, based on repeated observations, was, at a *minimum*,
> 20db. I don't believe you'll do that with a 2-element yagi!
>
> I have 40 quarter-wave radials, on the ground with poor soil, and that
> likely contributes to performance. The elements were (and still are)
> 1-3/4-inch diameter aluminum camouflage support tubes which are readily
> available in my area. They are easy to erect and are guyed, four ways,
> with light Dacron line at the 28-foot level.
>
> I did consider adding a third, in-line, element but it's just one of
> those things I never got around to and by the time I retired I had the
> 4-square in place. In retrospect it may have been a better idea to do
> the third element at a right-angle to the 2-element array to allow 4
> directions with 3 elements. The coax phasing system is still useful with
> one vertical common and the unused vertical simply switched and floating
> to isolate it from the active elements.
>
> Good luck!
>
> --
> Jack, W6NF
> Silver Springs, NV
> DM09ji
>
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 10.0.1424 / Virus Database: 2112/4809 - Release Date: 02/14/12
>
_______________________________________________
UR RST IS ... ... ..9 QSB QSB - hw? BK
|