Topband: Location of beverage close to 60 ft hill
wa3mej at comcast.net
wa3mej at comcast.net
Thu Nov 17 12:57:51 PST 2011
I only have about 491 ft of window line and thats what I am using for the two
direction beverage. Placement is in part dictated by the hill but mostly the rationalle
for the 300 or so feet from the inverted L is that it has a lot of noise. It is terrible actually
much of which is due to the McMansions they built in the farmers field next to me.. UGH!
I didnt realize how good I had it. .. you know the ones.. they have several large screen
plasma TVs and loud parties during football, baseball, hockey and basketball season.
Geeze thats just about all year of interference.
ANyhow over the last 5 years it has gotten progressively worse. I dont want to take a chance
on ANY noise being picked up on the beverage and I thought that the hill would be a nice
natural barrier and it just happens to be about 300 ft away.
Hummmmm I wonder .. leme see can I paint a target on the side of their houses and call in a
JDAM strike to get rid of the noise.. OHH NO cant .. sorry thinking out loud again.
Seriously.. it is all about mitigating as much noise as possible.
Thanks to all of those that responded with encouragement during this effort.
Date: Thu, 17 Nov 2011 02:11:52 -0500
From: "Tom McAlee" <tom at klient.com>
Subject: Re: Topband: Location of beverage close to 60 ft hill
To: <topband at contesting.com>
Content-Type: text/plain; charset="UTF-8"
Go for it. I live in the middle of the Appalachians and my Beverage wires go up and down many hills and valleys and cross many ravines and work great. On their worst day they still hear things my TX vertical couldn't hear on its best day :)
> Comments Please
1. Why the need to keep it 300' from the inverted L? You can read a lot about how they should be far apart, but (outside of multiband contest stations where one radio is trying to listen on the Beverage while another is transmitting) it may not be so important in practice. I will explain my experience...
A few years ago I put up 580' Beverage antennas for NW, NE, SE, and SW. I read that they should be far from the TX antennas, so the closest point from any of those RX antennas to any TX antenna is about 1000'.
To cover the "missing" directions, I put up a 4 square receive antenna from a popular manufacturer. But, I found that the Beverage antennas were (usually, but not ALWAYS) better than the 4 square even in its favored directions. So, I decided to put up Beverages for N, E, S, and W also.
N and S were no problem. But, when it came to E and W there was an issue. All of my Beverage antennas are installed on my neighbors property. It is 32 acres (surrounded east through west by 1.6 million acres of national forest!) but very "long". It is about 400' wide by about 3200' long with an odd triangle shape at the far end, all pointed slightly northwest. I am on the west side of that property.
A 580' East/West Beverage would just not fit on his property unless I put it in that odd triangle area at the end, which was about 2500' from my house! Alternatively, I could put it in the area where his property and my property lined up. That would give me 800' E/W to work with, but it would mean that the Beverage would come within 100' of my TX vertical (and the miles upon miles of radial wires that lay on/in the ground around them).
I consulted my friend and antenna mentor Frank, W3LPL. Frank suggested that I first put up the E/W Beverage where it was close to the TX vertical. If the noise wasn't any louder than it was on the other 6 Beverage directions it was fine. Otherwise, he recommended going the 2500' away route.
I did as he suggested and it turned out to be just fine. My E/W Beverage, which runs within 100' of my 160m TX vertical and 80m vertical array, doesn't have any more noise than the other 6 directions whose combined closest point is 1000' away from the TX antennas (the furthest points are much further!) The S/N ratio on the E/W antenna is not discernibly different than the other 6 directions.
If I were a multi-band (multi/multi or SO2R) contest station I suspect I would have issues trying to listen on that antenna while transmitting. But, for DXing purposes, it works very well.
It is worth noting that this antenna merely "passes by" one or more TX verticals within 100'; the feedpoint is several hundred feet from any TX vertical and doesn't line up with the base of any TX vertical in a targeted direction.
2. You said your target was EU and AF. I have found (from southwestern VA where the bearings aren't much different than they are in MD) that an EU Beverage and an AF Beverage are two different antennas. At least with 580' antennas, 45 degrees is great to EU and northern AF while 90 degrees is great to central/southern AF (and ok to northern AF). A 580' Beverage pointed at EU won't hear central and south AF very well. If you can do two, I'd recommend one at 45 degrees and one at 90 degrees. If not, I'd recommend one at 60 degrees.
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