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Re: [TowerTalk] Quad vs SteppIR

To: kk9a@arrl.net
Subject: Re: [TowerTalk] Quad vs SteppIR
From: david jordan <wa3gin@erols.com>
Date: Mon, 30 Aug 2004 13:50:29 -0400
List-post: <mailto:towertalk@contesting.com>
clarify please...

Noise from point source such as a tower or building and percepitation static created when dropplets of rain or snow flakes that are charged come in contact with the elements of a bare wire or beam antenna.

When pointing a low antenna at a tall tower is the direction of the storm front also in the same direction as the tall tower? Is the noise increase due to a local noise source like the taller tower or is the low beam pointing into the noise source behind it or are you hearing two separate noise sources?

In the winter I can hear an approaching snow storm on my 160m dipole. Has anyone experienced a storm front in the winter listening on a beam and then turned the beam away from the approaching front and heard the noise floor drop?

My experience is there are several noise source scenarios. The storm front which could be at a distance and approaching (not local percepitation static), the combination of the local static due to charged rain drops or snow flakes as well as the mass of the storm moving in the direction the beam is facing, and the third being the local static produced by the charged rain drops and snow flakes on the beam and other objects in the vicinity of the beam.

I've heard the distant noise of an approaching snow storm and the distinct pops due to descrete discharges of drops of rain on the beam elements. These are very different sounding noise sources. Once the approaching storm has arrived I've not been able to hear the distinct discharges because the noise floor is too high to distinguish...

I would think the Stepper would be less suseptible to the distinct discharge noise from rain drops and snow flakes because the copper elelments are protected from the charged particles by the fiberglass tubing, but would have no benefit from the noise produced by an approaching storm front or noise while in the mist of a storm.

I've enjoyed using loop antennas in part because they appear to me to be less suseptible to man-made noise, esp. when fed with shielded twin lead to reduce common mode noise from long vertical runs of single coax feds.

The question is really whether these noise sources prevent us from hearing that DX station we're tried to work for the past 3 years!

73,
dave
wa3gin

kk9a@arrl.net wrote:

There are times during storms that my upper antennas have heavy static and
the lower ones are much quieter.  Perhaps your antenna is low and less prone
to static than your buddies?

John KK9A


----- Original Message ----- From: "Richard M. Gillingham" <rmoodyg@bellsouth.net> To: <N2TK@arrl.net>; "'Tom Rauch'" <w8ji@contesting.com>; <towertalk@contesting.com>; "'Bill Ogden'" <ogden@us.ibm.com> Sent: Monday, August 30, 2004 15:20 Subject: Re: [TowerTalk] Quad vs SteppIR


I can't speak for snow static, living in south Florida, but the steppir is less prone to precip static because (I think) of the fact that the elements are enclosed in a "radome"... When some of my local buddies are complaining of precip static during rain storms, I don't hear it. That's not to say you won't hear static crashes from lightning. There's plenty of that down here. (grin)

There are certainly more knowledgable folks on here, but that's my
experience.

Good luck,
Gil, W1RG
3el up since Aug 2002.



----- Original Message -----
From: "N2TK" <tony.kaz@verizon.net>
To: "'Tom Rauch'" <w8ji@contesting.com>; <towertalk@contesting.com>; "'Bill
Ogden'" <ogden@us.ibm.com>
Sent: Monday, August 30, 2004 11:13 AM
Subject: RE: [TowerTalk] Quad vs SteppIR




Hi Tom,

When I had a quad and monobanders, the quad was always quieter from snow
static than the monobanders. Was wondering if the SteppIR would be quieter
than a regualr aluminum beam during a snow storm since the snow would be
in
contact with fiberglass instead of aluminum? Or would the static charge be
the same regardless of material?
Tnx
N2TK, Tony

-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of Tom Rauch
Sent: Monday, August 30, 2004 10:54 AM
To: towertalk@contesting.com; Bill Ogden
Subject: Re: [TowerTalk] Quad vs SteppIR



I am wondering if a 3 element SteppIR would provide any


noticable


improvements in my situation. The SteppIR is probably


easier to handle and


the 180 degree switch appears to be a very nice feature,


but is this


sufficient to justify switching? Does anyone have


experiences about quad


vs SteppIR?


Hi Bill,

This is all based on "how it works" data, not an actual comparison. I've
had
quads and Yagis, and the SteppIR is nothing but a Yagi.

If both your old quad and the proposed SteppIR antennas both have
reasonable
efficiency, you can expect performance to be roughly proportional to boom
length, assuming the number of elements is nearly optimum for any given
boom
length. This means the SteppIR should at least equal if not actually
improve
performance as long as it has a longer boom. My bet is that it would
actually improve your system a few dB for both receiving and transmitting.

I almost hate to say this, but an occasional reminder is due from time to
time. A quad has no real gain advantage over a similar size Yagi. The
original "2dB" thing came from flawed measurements of a scaled model by a
W2
and W6 long ago, and once it was in print that was it...it took on a life
of
its own. At some heights a small quad antenna can show a little advantage
(perhaps 1 dB) and at other heights a slight loss over a similar boom
length
yagi. Overall they are about equal, although for some reason long quads
did
not fair well in actual measurements (Wayne Overbeck N6NB and Dave Bell
W6AQ, CQ Magazine, May 1982).

Another quad myth is capture area, but physical aperture is not the same
as
electrical aperture or "capture area".
Capture area only relates to gain and frequency, so any antenna with the
same gain on the same frequency has the same capture area! That's true if
one is a big box, and the other is a small single plane element. Capture
area also does not determine S/N ratio, so it a moot point anyway.

Directivity sets receiving, not gain or capture area (more correctly
called
effective aperture). I would expect the SteppIR to receive better, because
it should have better directivity. The exception might be in times of
inclement weather, since the quad generally has less of a corona
(P-static) problem. In the few quads I've had here, that was the only
advantage I ever saw when comparing them to similar size Yagi's.

73 Tom


_______________________________________________


See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with
any
questions and ask for Sherman, W2FLA.

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_______________________________________________


See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with
any questions and ask for Sherman, W2FLA.

_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk



_______________________________________________


See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.

_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk



_______________________________________________

See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions and ask for Sherman, W2FLA.

_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk



_______________________________________________

See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions and ask for Sherman, W2FLA.

_______________________________________________
TowerTalk mailing list
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