HFU HF Underground
Technical Topics => Equipment => Topic started by: K5KNT on October 15, 2013, 1436 UTC
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OK. I've been convinced that I need to get an outdoor antenna. I just having trouble figuring out how to best place one keeping the cost to a minimum. So, again, I'm asking for help. ;)
Below is a overhead photo of my home, courtesy of Google Maps. I've rotated the image so North is up. The black line at the top is the power line. The blue dot is the air conditioner and the red dot is the location of the window to the room my computer and radio are located. The green trees in the lower right are the neighbor's. The front of the house faces South. The white "V" shape is tree limbs I erased as they are no longer there. The structure in the upper right is an un-insulated storage shed. There are two Mesquite trees in the backyard. One located in the upper left corner and the other by the shed at the top point of the "V". the back yard is surrounded by a 8' wooden privacy fence. Sorry, but I don't have dimensions.
Any suggestions would be greatly appreciated.
(http://i1293.photobucket.com/albums/b598/Kent_Frazier/Radio/House_zps4020a1b5.png) (http://s1293.photobucket.com/user/Kent_Frazier/media/Radio/House_zps4020a1b5.png.html)
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Skinny longwire out the window, as high over the AC as possible, and back to the shed if you can swing it. To the chimney if you just want to give it a quick try and not burn up an extra 50 feet. Don't go anywhere near the central back yard where the power line is.
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Yeah, I cannot emphasize enough what moof said. Make sure that under no circumstances does your antenna get anywhere near the power line.
As I am a huge fan of loop antennas, I would see what you can do in that department. This might be a good application for a resonant loop. I'd consider running a loop around the fence (and I guess along the house for the southern side), but then you'd have the power line right over it. Also: Bad for possible noise pickup, and extra bad if the power line falls on the loop.
If you are allowed to use that pine tree in the front, i wonder about putting a dipole from it, to the top of the chimney, then down to the shed. Looks like there's enough room for a 43 mb dipole that way - maybe? Otherwise, same dipole idea but going down to the ground near the tree, maybe in front of it of needed. Not ideal, but at least you have an outside antenna, and could run coax to it.
I feel for you guys with overhead power lines.
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Thanks. It is good to know I was on the right track thinking that the back yard is no-go due to the power line bisecting it. I'll take a closer look at routing a line to the shed. I'll try to get twine to run a test this weekend.
Kent
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Higher would be better, but you have that power line in your backyard which kind of throws a wrench into the works. I like Chris's recommendation of a loop placed on top of your fence. Only issue you may run into is inteference/qrn from that power line. You may have to experiment a bit.
Are you going to be using this as a transmitting antenna also? If so, you may have issues with placement on the fence and also length will become critical.
Steve
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Are you going to be using this as a transmitting antenna also? If so, you may have issues with placement on the fence and also length will become critical.
Steve
No plans to transmit. At the moment I only have a 2-meter/440Mhz Dual band mobile and it is currently in storage.
The loop sounds interesting, but the breaker box is located on the outside just below where the power line comes to the house. I'm not too sure about getting antenna wire around that.
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The loop sounds interesting, but the breaker box is located on the outside just below where the power line comes to the house. I'm not too sure about getting antenna wire around that.
Gotta love that sloppy southern construction. I really wish they'd stop doing that shit and put it inside where it belongs.
I would probably try and orient a long wire at a 90 degree angle to the rear power lines (the main HV, not the drops). Failing that, a resonant loop on a small rotator in the front yard would be your best bet for quiet RX. I'd probably use a loop in your situation.
+-RH
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Remember KISS. If you run 30 feet to the chimney or across the front and it sucks, aint no way running an extra 50 feet won't suck.
I'd buy a 100ft reel of relatively thin gauge stranded wire for under 10 bucks, run it north-south to the chimney or out back to the shed far away from the power line, and see what happens. If it works out, then maybe try a loop as well around the house rafters or along the fence. You will know real fast if you have terrible power line problems like me. Good luck!
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What moof said. If thirty feet works w/o a lot of noise pick-up, take it out to 50 or 60 feet. Try a 9:1 Unun at the window end of the long wire. They can clean up a lot of stray noise before it gets to your receiver.
One of the big problems in suburban neighborhoods is the electronics your neighbors have that kick out noise. I had a strange 12 hour on - 12 hour off QRM problem about 15 years ago. It stopped when the cops took one of the neighbors away for having an indoor weed grow. (It also explained why he was always running into stuff trying to back down his driveway.)
I miss ol' Bong Boy. Every day was adventure with him on the block.
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moof: I like KISS, I'll try going to the chimney first.
Pigmeat: I'm guessing the 9:1 Unun is something I can build?
Sorry, but I don't have much experience with antennas. My only ham rig is a 2m/70cm mobile in my car.
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This morning I ordered a Par EF-SWL antenna from Universal Radio. I'm looking forward to getting it up and listening.