[TowerTalk] Fw: 4 Sq array Dx or Hi Z

Thu Sep 6 22:24:08 EDT 2012

----- Original Message ----- 
From: "Gene Fuller" <w2lu at rochester.rr.com>
To: "Dan Schaaf" <dan-schaaf at att.net>
Sent: Thursday, September 06, 2012 10:23 PM
Subject: Re: [TowerTalk] 4 Sq array Dx or Hi Z


> Hi John -
>
> Whatever focuses the transmit signal also focuses the receive signal. .
>
> What we're looking for is an antenna with the most tightly focused 
> aperture in the desired direction. This brings into play both horizontal 
> beamwidth AND vertical beamwidth. An antenna might present a very high F/B 
> for a given radiation angle and still have a very large forward vertical 
> beamwidth in the desired direction and thus not present a good (S+N)/N. 
> From the little computer analysis I have done  on vertical arrays my 
> impression has been that with short vertical elements and good phasing it 
> is possible to get very high F/B but the forward lobe may still be very 
> broad in the vertical plan. As the height of the verticals is increased 
> thevertical aspect of the lobes shrink down, thus excluding noise  that 
> you don't want, until it gets down to the point that it also starts 
> excluding signals that you do want. East coast guys working into Europe, 
> with 80 meter 4 sqrs with 90 foot verticals, have found that they work 
> like gangbusters for opening and closing the band when desired radiation 
> angles are way low, but as the band becomes really "opened", and  the 
> desired radiation angle increases they loose out to the guys with arrays 
> using 60 foot verticals and a little higher radiation angle. The extra db 
> or so that the longer elements offer is soon lost  by focusing the energy 
> at too low an angle. Some of why beverages work so great is because their 
> forward lobe is narrow in both the vertical and horizontal planes, but 
> again there are optimum  lengths. Because of space limitations, for 
> receive, I use two phased four direction pennant systems. Very good F/B, 
> but the forward lobe is perhaps 60-80 degrees wide in the vertical plane 
> and lets too much high angle noise in. At least two guys I know of, within 
> 100 miles of me, using ~ 600 foot beverages that run circles around me 
> receiving. Both also have full sized 4 sqrs and I've heard them say that 
> the full sized 4 sqr,  properly tuned, is nearly as good as the beverage 
> for receive.
>
> Bottom line, when someone offers a small receive antenna system, claiming 
> great F/B, try to get them to specify the vertical beamwidth.
>
> There may be a silver bullet out there but if there is it's mighty 
> illusive.
>
> Gerne / W2LU
>
>
> ----- Original Message ----- 
> From: "Dan Schaaf" <dan-schaaf at att.net>
> To: "W1JCW" <W1JCW at hotmail.com>; <john at kk9a.com>; 
> <TowerTalk at contesting.com>
> Sent: Thursday, September 06, 2012 7:26 PM
> Subject: Re: [TowerTalk] 4 Sq array Dx or Hi Z
>
>
>>I have heard, and I have been in conversation with both suppliers on 4 SQ 
>>and 8 circle receive arrays. And I have talked to guys who have owned both 
>>receive arrays and beverages.
>> The overall conclusion is that the vertical  receive arrays outperform 
>> the 4 SQ TX array and are equal to 1,000 ft bevs.
>>
>> The reason that they outperform the 4SQ TX array is that there is no real 
>> noise rejection on the 4 SQ TX array. They are just arrays that focus 
>> transmit energy.
>>
>> Whereas, the receive arrays use fancy footwork in phasing that actually 
>> reduces the noise. It reduces noise from all directions that are not in 
>> the direction of reception.
>> So, for example, if you want to copy a weak signal to the northeast, then 
>> noise from all other directions is cancelled.
>>
>> Normally, It is the sum of noise from all directions that smothers out 
>> the signal of interest. Remove the noise from east , south, west, north 
>> and all you have is noise from the northeast + signal.
>>
>> I am embarrassed when my ham friend 300 miles from me hears DX on 160 and 
>> I hear nothing but noise on my vertical and on my K9AY Loop and my Mag 
>> Loop.
>>
>> Which manufacturer to buy from, you do the research. I bought a 1/4 acre 
>> next to my house for the sole purpose of installing a dual 4 SQ RX Array, 
>> 45 degrees apart so that I have 8 cardinal points. 80 ft radius for this 
>> system. When I have the available cash, I will install the system.
>> I know which one I most likely will buy.
>>
>> Get on the Low Band chat room and ask for opinions. Those guys are the 
>> ones to talk to. They live for 160 meters.
>>
>>
>>
>> Best Regards
>> Dan Schaaf
>> =================================
>> K3ZXL www.k3zxl.com
>> 60 Meters www.60metersonline.net
>> =================================
>> NOBSKA www.nobska.net
>> Cape Cod Instruments www.gnm-inc.com
>> =================================
>>
>> -----Original Message----- 
>> From: W1JCW
>> Sent: Thursday, September 06, 2012 6:52 PM
>> To: john at kk9a.com ; TowerTalk at contesting.com
>> Subject: Re: [TowerTalk] 4 Sq array Dx or Hi Z
>>
>> I would think a full size Tx and Rx four square would work better due to 
>> size and you can Tx on it.
>>
>> For now I wanted something to hear better as I have other Tx avenues.
>>
>> If I had the room, time and resouces I would build a 160 and 80 four 
>> square that I can Tx on.
>>
>> 73-
>> W1JCW
>> John
>>
>>
>> From: john at kk9a.com
>> Sent: Thursday, September 06, 2012 9:29 AM
>> To: TowerTalk at contesting.com
>> Subject: Re: [TowerTalk] 4 Sq array Dx or Hi Z
>>
>>
>> That is great information, John.
>>
>> I am curious if these work any better for receiving than a full sized
>> vertical TX four square?
>>
>> John KK9A
>>
>>
>> To: <TowerTalk at contesting.com>
>> Subject: [TowerTalk] 4 Sq array Dx or Hi Z
>> From: "W1JCW" <w1jcw at hotmail.com>
>> Date: Wed, 5 Sep 2012 14:15:43 -0500
>>
>>
>> Hi Z seems to have a better mouse trap when compared to Dxe.
>>
>> The methods and how to handle RF from near by active elements is the key
>> and
>> since I run QRO and this is important as
>> many indicated this to be an issue with Dxe.
>>
>> I was looking at a used 4 sq from Dxe but after checking into the Hi Z
>> packages
>> I will get more bang for the buck
>> in the long run.
>>
>> 73-
>> W1JCW
>> John
>>
>>
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>>
>>
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