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#1
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On Tue, 8 Nov 2005 13:51:06 -0800, "Michael" wrote:
I get a lot of noise from my random wire antenna. It transmits very well but is very noisy in receive. My neighbor put up a 280 foot loop antenna which Ok. he feeds with ladder line. He feeds the ladder line from a 4 to 1 balun to coax. The coax comes from a tuner. His setup performs very well on all bands down to 75 meters. I went over to his shack last night and listened to his receiver on 75. I was really impressed with the lack of noise. I can safely say the difference in noise was profound. He has this loop surrounding his So, the noise is "profoundly" less (whatever that means), but what about signals that you want to hear, and how does it perform transmitting. You see, a 30dB attenuator would profoundly reduce the noise.... and the desired receive signals, and the tx signal, but it isn't necessarily better. You probably know the answers, you just didn't tell us. It is often the case that the best antenna for transmission is the one that makes the most noise where you want to be heard, and the best antenna for receiving is the one that gives the best S/N ratio (not necessarily the best S meter deflection) for stations from that place, and they may not be the same antenna. Owen -- |
#2
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Michael wrote:
Has anybody else had this experience with loops? Only the past three generations. :-) -- 73, Cecil http://www.qsl.net/w5dxp |
#3
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Ah yes grasshopper - zee loops - zay are good.
The loop helps reduce noise since its dc-shorted and no static buildup, and your socks won't stick to it. ;-) but it takes more trees to hold it up "Michael" wrote in message ... I get a lot of noise from my random wire antenna. It transmits very well but is very noisy in receive. My neighbor put up a 280 foot loop antenna which he feeds with ladder line. He feeds the ladder line from a 4 to 1 balun to coax. The coax comes from a tuner. His setup performs very well on all bands down to 75 meters. I went over to his shack last night and listened to his receiver on 75. I was really impressed with the lack of noise. I can safely say the difference in noise was profound. He has this loop surrounding his house at a 30 ft. height. It is arranged in a square. Has anybody else had this experience with loops? It looks like I have room to put up a triangular loop. Will this work as well? Can I use the same tuner I have now and just feed a coax into a balun. Or, should I put the balun in the tuner and come straight out with ladder line? There is a lot of room in this tuner. It is an old remote controlled tuner surplused from a ship. |
#4
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Michael,
I've had sort of the same experience with a loop antenna. I'd say it was probably about the same for most everyone. As far as where to put the balun and how to feed the thing, I honestly don't think it's going to make much difference. What would be easiest and 'best' for you? That's how I'd do it... 'Doc PS - Are loops the 'end-all of antennas? Huh, good question, and the answer is probably, no. But, I've had good luck with mine... |
#5
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On 2005-11-08, Michael wrote:
Has anybody else had this experience with loops? It looks like I have room to put up a triangular loop. Will this work as well? Can I use the same tuner I have now and just feed a coax into a balun. Or, should I put the balun in the tuner and come straight out with ladder line? Following Walt's (W2DU) ideas, I have a 259' horizontal delta (triangle) loop (two trees and a wooden pole) fed at almost middle of one side (convenience, not design) by 450 ohm ladder line. This is soldered directly to a ferrite bead choke balun (ala W2DU) which, via PL-259s and barrel connector, goes to a very short piece of 50 ohm coax (about 6') directly into the house to the unbalanced SO-239 input of my MFJ-941E. Works like a charm on all bands 80-10m, no RF in the room, and good signal reports. ....Edwin, KD5ZLB -- __________________________________________________ _____ "Once you have flown, you will walk the earth with your eyes turned skyward, for there you have been, there you long to return."-- da Vinci ... www.shreve.net/~elj |
#6
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Michael.
Why not try a folded dipole made from 300 ohm TV twin lead? Cut it for the band you are interested in. A tuner or a balun to 52 ohm coax to match your rig will be necessary. I was impressed with the lack of noise pickup from the one I put up a couple of years ago. Cut for 75 meters. My home and antenna are just a hundred feet or so from a power line with 3 sets of high voltage lines and sometimes they are very noisy on a regular dipole, but not the folded dipole. Paul, KD7HB |
#7
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I get a lot of noise from my random wire antenna. It transmits very well but
is very noisy in receive. My neighbor put up a 280 foot loop antenna which he feeds with ladder line. He feeds the ladder line from a 4 to 1 balun to coax. The coax comes from a tuner. His setup performs very well on all bands down to 75 meters. I went over to his shack last night and listened to his receiver on 75. I was really impressed with the lack of noise. I can safely say the difference in noise was profound. He has this loop surrounding his house at a 30 ft. height. It is arranged in a square. Has anybody else had this experience with loops? It looks like I have room to put up a triangular loop. Will this work as well? Can I use the same tuner I have now and just feed a coax into a balun. Or, should I put the balun in the tuner and come straight out with ladder line? There is a lot of room in this tuner. It is an old remote controlled tuner surplused from a ship. |
#8
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![]() "I get a lot of noise from my random wire antenna. It transmits very well but is very noisy in receive. My neighbor put up a 280 foot loop antenna which Ok. he feeds with ladder line. He feeds the ladder line from a 4 to 1 balun to coax. The coax comes from a tuner. His setup performs very well on all bands down to 75 meters. I went over to his shack last night and listened to his receiver on 75. I was really impressed with the lack of noise. I can safely say the difference in noise was profound. He has this loop surrounding his So, the noise is "profoundly" less (whatever that means), but what about signals that you want to hear, and how does it perform transmitting. Well, I would not be raving about his antenna if it also reduced the signals you want to hear. He gets the same kind of signal reports that I do. We were both on the same net one night and we were both be received equally at various spots. Clearly, mine transmits as well as his. You see, a 30dB attenuator would profoundly reduce the noise.... and the desired receive signals, and the tx signal, but it isn't necessarily better. When I listened to our local North Dakota Data Net, I heard all the checkins like they were much much closer. No Noise! I should have been more specific. The S?n ratio was profoundly better than my puny random wire. However, I do not know yet if I am up to putting up 3 or 4 32 foot poles or higher. What a drag. I will probably do this next spring. It is getting too cold to make the task a very pleasant one now. You probably know the answers, you just didn't tell us. It is often the case that the best antenna for transmission is the one that makes the most noise where you want to be heard, and the best antenna for receiving is the one that gives the best S/N ratio (not necessarily the best S meter deflection) for stations from that place, and they may not be the same antenna. Owen -- |
#9
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![]() "Hal Rosser" wrote in message . .. Ah yes grasshopper - zee loops - zay are good. The loop helps reduce noise since its dc-shorted and no static buildup, and your socks won't stick to it. ;-) but it takes more trees to hold it up Oh thank you Master Rosser. I am a little wiser now. How long before I can take the pebble from your hand or maybe just kick butt? |
#10
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Michael wrote:
I had never hear of a loop antenna back in the 50s. Loops started to come into their own with the invention by C. C. Moore of the Cubical Quad circa 1939. -- 73, Cecil http://www.qsl.net/w5dxp |
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