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#11
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On May 23, 5:15*pm, wrote:
On Sun, 23 May 2010 16:58:44 -0700 (PDT), bpnjensen wrote: On May 23, 4:33*pm, dave wrote: RHF wrote: On May 22, 10:03 am, "John *wrote: I have a wood fence around my back yard. Across the back stretch is 79 feet. The fence extends 76 feet from there along each side of my house which is 50 feet wide, leaving around 14 feet on each side of the house. The back of the house to the fence is 37 feet . The eve of my two story house is, if I remember right, about 23 feet above the ground. I want to erect a random wire antenna of insulated 12 gauge wire from one corner of the fence in the back, lead it up to the middle of the house to an insulator, then back down to the other corner of the fence, where the feedpoint will connect at the end. The back of my house faces due North. The antenna will be held about 8' feet off the ground at the fence corners by schedule 40 PVC pipe. I want to juse the feeline system as described by John Doty in this article:http://www.hard-core-dx.com/nordicdx...eed/feed1.html I have a Radio Shack DX-398 equivalent of the Sangean ATS-909. I was thinking the two ground rods will be set in *a hole 1 foot in diameter filled with a Bentonite slurry. I was wondering if the random wire folded into such an inverted V facing due North will have good reception qualities. The previous residence I erected an inverted L random wire antenna and received excellent results, but seemed very directional. I am hoping the inverted V shape will help diversify the direction of reception somewhat at this house. What do you all think? John Smith, Consider using the Par Electronics End-Fed Shortwave Listener's (EF-SWL) Antenna http://groups.google.com/group/rec.r...68cb105b4a370b http://groups.google.com/group/rec.r...11c0ac4f084b87 * . Rig EF-SWL as an Inverted "L" Antenna starting with a 15 Foot Vertical Up-Leg with a 30 Foot Horizontal Out-Arm http://groups.google.com/group/rec.r...f41e85486b0ed9 * . SWL -Newbies- Installing an Inverted "L" Antenna : The Right-Way ! http://groups.google.com/group/rec.r...ca62e0c0e838ea * . All-Band Sloping Inverted "L" Antenna -by- Rolf Brevig [LA1IC] http://groups.google.com/group/rec.r...0de363c21d19ba * . hope this helps - iane ~ RHF * . Center feed it at the apex with RG6. *Good to go. *Great antenna. How do you center feed an inverted L or a PAR SWL? *This I gotta see! He is talking about the original V shaped antenna that John described. He is saying - split it in half and feed it at the top insulator with coax instead of feeding it at the end with a balun. Jim- Hide quoted text - - Show quoted text - I see - and the advantage is less directionality, like a dipole. But if that is what you seek, then why not just end-feed the PAR and set it up as a sloper with the fed end near the gournd and the far end up high? That's what Dale recommends, and you still get more omni out of it plys good noise isolation. No surgery required. Either that or take some plain wire and do the split version. If I got the PAR, I'd be hesitant to take a nice, slighlty pricey antenna and chop-shop it. Bruce |
#12
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John Smith wrote:
I have a wood fence around my back yard. Across the back stretch is 79 feet. The fence extends 76 feet from there along each side of my house which is 50 feet wide, leaving around 14 feet on each side of the house. The back of the house to the fence is 37 feet . The eve of my two story house is, if I remember right, about 23 feet above the ground. I want to erect a random wire antenna of insulated 12 gauge wire from one corner of the fence in the back, lead it up to the middle of the house to an insulator, then back down to the other corner of the fence, where the feedpoint will connect at the end. The back of my house faces due North. The antenna will be held about 8' feet off the ground at the fence corners by schedule 40 PVC pipe. I want to juse the feeline system as described by John Doty in this article: http://www.hard-core-dx.com/nordicdx...eed/feed1.html I have a Radio Shack DX-398 equivalent of the Sangean ATS-909. I was thinking the two ground rods will be set in a hole 1 foot in diameter filled with a Bentonite slurry. I was wondering if the random wire folded into such an inverted V facing due North will have good reception qualities. The previous residence I erected an inverted L random wire antenna and received excellent results, but seemed very directional. I am hoping the inverted V shape will help diversify the direction of reception somewhat at this house. What do you all think? I have a 65' random wire located about 225 feet from my house with a 9:1 matching transformer at the antenna end, and roughly 300 feet of coax running underground (in plastic conduit) between the antenna and the house and then up and over across my attic before coming down the wall where my radio is. There's a ground at the matching transformer, and one at the house. I've got ferrites at each end too. It's a wonderful antenna. My noise floor is incredibly low. A concern I have with the antenna you're proposing is you're bringing the antenna back to the house - where all the electrical noise you're looking to avoid is located. Your radio really doesn't need a big antenna. Design yours so you keep the antenna as far from your house (and your neighbors homes) as possible. 15-20 feet is probably plenty for that radio. RFI strength goes down by a square of the distance. Put your antenna twice as far away and you get 1/4 of the noise signal. Three times as far away and you get 1/9 of the noise signal. Something to consider is if you're even thinking about getting your ham ticket some day, it's worth spending the money up front to use low loss coax or heliax. My antenna is useless for tx, and digging up all that pipe to replace my coax just isn't an attractive option. |
#13
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On May 24, 8:00*am, "Mark S. Holden" wrote:
John Smith wrote: I have a wood fence around my back yard. Across the back stretch is 79 feet. The fence extends 76 feet from there along each side of my house which is 50 feet wide, leaving around 14 feet on each side of the house. The back of the house to the fence is 37 feet . The eve of my two story house is, if I remember right, about 23 feet above the ground. I want to erect a random wire antenna of insulated 12 gauge wire from one corner of the fence in the back, lead it up to the middle of the house to an insulator, then back down to the other corner of the fence, where the feedpoint will connect at the end. The back of my house faces due North. The antenna will be held about 8' feet off the ground at the fence corners by schedule 40 PVC pipe. I want to juse the feeline system as described by John Doty in this article: http://www.hard-core-dx.com/nordicdx...eed/feed1.html I have a Radio Shack DX-398 equivalent of the Sangean ATS-909. I was thinking the two ground rods will be set in *a hole 1 foot in diameter filled with a Bentonite slurry. I was wondering if the random wire folded into such an inverted V facing due North will have good reception qualities. The previous residence I erected an inverted L random wire antenna and received excellent results, but seemed very directional. I am hoping the inverted V shape will help diversify the direction of reception somewhat at this house. What do you all think? I have a 65' random wire located about 225 feet from my house with a 9:1 matching transformer at the antenna end, and roughly 300 feet of coax running underground (in plastic conduit) between the antenna and the house and then up and over across my attic before coming down the wall where my radio is. *There's a ground at the matching transformer, and one at the house. *I've got ferrites at each end too. It's a wonderful antenna. *My noise floor is incredibly low. A concern I have with the antenna you're proposing is you're bringing the antenna back to the house - where all the electrical noise you're looking to avoid is located. Your radio really doesn't need a big antenna. *Design yours so you keep the antenna as far from your house (and your neighbors homes) as possible. *15-20 feet is probably plenty for that radio. RFI strength goes down by a square of the distance. *Put your antenna twice as far away and you get 1/4 of the noise signal. *Three times as far away and you get 1/9 of the noise signal. Something to consider is if you're even thinking about getting your ham ticket some day, it's worth spending the money up front to use low loss coax or heliax. *My antenna is useless for tx, and digging up all that pipe to replace my coax just isn't an attractive option.- Hide quoted text - - Show quoted text - Dang! I'd give my right arm for that much space to erect an antenna. |
#14
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bpnjensen wrote:
On May 24, 8:00 am, "Mark S. Holden" wrote: I have a 65' random wire located about 225 feet from my house with a 9:1 matching transformer at the antenna end, and roughly 300 feet of coax running underground (in plastic conduit) between the antenna and the house and then up and over across my attic before coming down the wall where my radio is. There's a ground at the matching transformer, and one at the house. I've got ferrites at each end too. It's a wonderful antenna. My noise floor is incredibly low. A concern I have with the antenna you're proposing is you're bringing the antenna back to the house - where all the electrical noise you're looking to avoid is located. Your radio really doesn't need a big antenna. Design yours so you keep the antenna as far from your house (and your neighbors homes) as possible. 15-20 feet is probably plenty for that radio. RFI strength goes down by a square of the distance. Put your antenna twice as far away and you get 1/4 of the noise signal. Three times as far away and you get 1/9 of the noise signal. Something to consider is if you're even thinking about getting your ham ticket some day, it's worth spending the money up front to use low loss coax or heliax. My antenna is useless for tx, and digging up all that pipe to replace my coax just isn't an attractive option.- Hide quoted text - - Show quoted text - Dang! I'd give my right arm for that much space to erect an antenna. It doesn't suck. Before I had this one, my signal to noise level was a problem, even when I did the horizontal loop. But I really wish I'd used heliax. |
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