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Inverted L for AMBCB listening
I'm about to install a 125 ft long antenna 30 ft high.
Is there any advantage to bringing the far end back down to the ground or near the ground. What does this extra wire do to the impedance? Pattern? Thanks, Mikek |
#2
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Inverted L for AMBCB listening
In message , amdx
writes I'm about to install a 125 ft long antenna 30 ft high. Is there any advantage to bringing the far end back down to the ground or near the ground. What does this extra wire do to the impedance? Pattern? It will probably lower the various 'natural' resonant frequencies a little, and also change the angles and directions of signal pickup. However, I don't think that you're unlikely to notice much difference. If you do want to bring the far end down to ground level, you might like to consider the potential reduction of local noise by inserting a (typically) 9:1 impedance transformer and far end ground, and bringing the RF signal back to the house via coax. -- Ian |
#3
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Inverted L for AMBCB listening
"Ian Jackson" wrote in message ... In message , amdx writes I'm about to install a 125 ft long antenna 30 ft high. Is there any advantage to bringing the far end back down to the ground or near the ground. What does this extra wire do to the impedance? Pattern? It will probably lower the various 'natural' resonant frequencies a little, and also change the angles and directions of signal pickup. However, I don't think that you're unlikely to notice much difference. If you do want to bring the far end down to ground level, you might like to consider the potential reduction of local noise by inserting a (typically) 9:1 impedance transformer and far end ground, and bringing the RF signal back to the house via coax. -- Ian I got the wire up this morning/afternoon, I did leave the wire long at the far end so it will reach the ground. I'm not sure what I will do with it yet. I'll add a little more info, it will have a dual purpose, First, I'm going to characterize it as a long wire for use with a crystal radio. I want to optimize it for that. I had thought about running a counterpoise along a fence, but I found a better tree that runs at an angle to the fence. How close does a counterpoise need to follow the antenna? How do you think a chain link fence will work as a (grounded) counterpoise? When the crystal radio excitement has run its course, I'll use it as an antenna for my general coverage radio, with that it's still mostly am BCB, but some 80 meter listening too. Thanks, Mikek |
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