----- Original Message -----
From: "Gene Fuller" <w2lu@rochester.rr.com>
To: "Dan Schaaf" <dan-schaaf@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@att.net>
To: "W1JCW" <W1JCW@hotmail.com>; <john@kk9a.com>;
<TowerTalk@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@kk9a.com ; TowerTalk@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@kk9a.com
Sent: Thursday, September 06, 2012 9:29 AM
To: TowerTalk@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@contesting.com>
Subject: [TowerTalk] 4 Sq array Dx or Hi Z
From: "W1JCW" <w1jcw@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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