Topband: rx array proximity to barbed wire fence
I am considering installing one of these hi-z or DXE buffered-type receiving 4-square arrays for 160/80. The best place on the property is on the north west corner - in a location about 400’ from the transmit vertical. It’s got a clear shot NE to EU and is about 600’ from the nearest house. However, that NW property corner location has old barbed wire fences that runs along the property line in the corner. I am curious if anyone has experience with this kind of array near barbed wire fencing. Thanks! 73/jeff/ac0c www.ac0c.com alpha-charlie-zero-charlie ___ Topband reflector - topband@contesting.com
Re: Topband: rx array proximity to barbed wire fence
Jeff, I live on what was once a pasture with barbed wire fencing about 90' diagonally from one corner of the 4-square. I didn't worry about the fence when I first installed the array and it seemed to work OK. When I was having what turned out to be a hardware problem, I cut the barbed wire for about an 100' length just to make sure it wasn't contributing to my problem. As best I could tell, there was no effect on receive performance either way. 73, Joe K2XX On 12/11/2012 2:36 PM, Jeff Blaine wrote: I am considering installing one of these hi-z or DXE buffered-type receiving 4-square arrays for 160/80. The best place on the property is on the north west corner - in a location about 400’ from the transmit vertical. It’s got a clear shot NE to EU and is about 600’ from the nearest house. However, that NW property corner location has old barbed wire fences that runs along the property line in the corner. I am curious if anyone has experience with this kind of array near barbed wire fencing. Thanks! 73/jeff/ac0c www.ac0c.com alpha-charlie-zero-charlie ___ Topband reflector - topband@contesting.com ___ Topband reflector - topband@contesting.com
Re: Topband: rx array proximity to barbed wire fence
On 12/11/2012 1:36 PM, Jeff Blaine wrote: I am considering installing one of these hi-z or DXE buffered-type receiving 4-square arrays for 160/80. The best place on the property is on the north west corner - in a location about 400’ from the transmit vertical. It’s got a clear shot NE to EU and is about 600’ from the nearest house. However, that NW property corner location has old barbed wire fences that runs along the property line in the corner. I am curious if anyone has experience with this kind of array near barbed wire fencing. Thanks! Hi Jeff: I currently run what amounts to a two element HI-Z RX array. My back yard has chain link fencing around 3 sides. I elected to put the antennas on top of the fence, and it has worked well. This may be a consideration for you. Each antenna is mounted on a piece of treated 2X2about a foot above the level of the fence; with the pre-amplifier housed in a plastic Folgers coffee can just below the base of the antenna. The array allowed me to work three new ones during, the CQWW contest, including D4C, and that completed DXCC on 160 for me. The original installation used metal coffee cans, and subsequently I changed that because I had problems keeping the lids on the metal cans. See http://www.suddenlink.net/pages/w5uc/160%20vertical.html 73, Mike, W5UC ___ Topband reflector - topband@contesting.com
Re: Topband: rx array proximity to barbed wire fence
Jeff - the southern periphery of my 8 circle vertical array (W8JI broad side/end fire passive version) is 75 feet from a barb wire fence that runs a quarter mile east and west. While one might claim some theoretical interaction I have not documented any or identified any performance degradation as a result. I see Big Gun Mike, W5UC, has a lot of experience with RX arrays close to fences has responded as well. GL with the array. 73 Joel W5ZN On Tue, Dec 11, 2012 at 1:36 PM, Jeff Blaine j...@ac0c.com wrote: I am considering installing one of these hi-z or DXE buffered-type receiving 4-square arrays for 160/80. The best place on the property is on the north west corner - in a location about 400’ from the transmit vertical. It’s got a clear shot NE to EU and is about 600’ from the nearest house. However, that NW property corner location has old barbed wire fences that runs along the property line in the corner. I am curious if anyone has experience with this kind of array near barbed wire fencing. Thanks! 73/jeff/ac0c www.ac0c.com alpha-charlie-zero-charlie ___ Topband reflector - topband@contesting.com -- 73 Joel W5ZN www.w5zn.org ___ Topband reflector - topband@contesting.com
Re: Topband: rx array proximity to barbed wire fence
While one might claim some theoretical interaction I have not documented any or identified any performance degradation as a result. I see Big Gun Mike, W5UC, has a lot of experience with RX arrays close to fences has responded as well. The rusty twisted-joint barbed wire fences by my RX antennas were a problem when I transmitted, but only when I tried to duplex. They were 2000 -3000 feet long and ran right past the TX antennas in a straight line, so I bet they had a whopping signal level. They generated noise like crazy while I transmitted. I think the real problem is all fences and all installations are different. If the fence has rusty joints and reradiates strong BC station mixing products, it will be an issue. If the fence is near power lines and reradiates noise, it can be a problem. If the fence reradiates propagated signals with significant intensity compared to over-the-air signals (pretty unlikely), it could be a problem. It really depends more on the fence and local layout of things than anything else, so the only way to really know is to just try it. 73 Tom ___ Topband reflector - topband@contesting.com
Re: Topband: rx array proximity to barbed wire fence
Tom, Having fought (and lost) a battle of harmonics from an environmental unintended mixer at the last QTH, I really can feel trouble with that blasted fence. The good news is that the transmit antenna is about 100' + from the fence, and the other antennas are several hundred feet further back yet. Trying to track down a thing serving as a mixer out in the open where you can get too it is a challenge I'm not fretting too much - IF it becomes trouble. 73/jeff/ac0c www.ac0c.com alpha-charlie-zero-charlie -Original Message- From: Tom W8JI Sent: Tuesday, December 11, 2012 5:39 PM To: Joel Harrison ; Jeff Blaine Cc: topband@contesting.com Subject: Re: Topband: rx array proximity to barbed wire fence While one might claim some theoretical interaction I have not documented any or identified any performance degradation as a result. I see Big Gun Mike, W5UC, has a lot of experience with RX arrays close to fences has responded as well. The rusty twisted-joint barbed wire fences by my RX antennas were a problem when I transmitted, but only when I tried to duplex. They were 2000 -3000 feet long and ran right past the TX antennas in a straight line, so I bet they had a whopping signal level. They generated noise like crazy while I transmitted. I think the real problem is all fences and all installations are different. If the fence has rusty joints and reradiates strong BC station mixing products, it will be an issue. If the fence is near power lines and reradiates noise, it can be a problem. If the fence reradiates propagated signals with significant intensity compared to over-the-air signals (pretty unlikely), it could be a problem. It really depends more on the fence and local layout of things than anything else, so the only way to really know is to just try it. 73 Tom ___ Topband reflector - topband@contesting.com ___ Topband reflector - topband@contesting.com
