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#1
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My antenna setup, comments please
My antenna setup is nothing but a random wire going from a tree/ tuner/ rig
in the basement about 60-70 feet total, I know it could be better but its all I can get away with for the moment. The ground is a rod thru the bottom of the sump where is always wet and I feel is good for RF, I hook the end of that to the back of the random wire tuner. My concern is...the wire coming from window to tuner/rig is about 15 feet and due to placement I cant shorten it much more, Should I use a coax from window to rig? Or just leave it alone? BTW I use low power about 30-40 watts CW and the setup seems to work fairly well on most bands..just concerned about loss and RF inside the shack. Any input appreciated, and thanks for reading gil |
#2
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Same setup I and many others used decades ago. One thing you might consider
doing is to move the tuner to the wall where the antenna enters (sounds like you're in a basement?). You could adjust the tuner anywhere within earshot of the rig by using a noise bridge and listening to the noise while adjusting the tuner. The Palomar Tuner Tuner is made for just this type of operation. They can be had on the used market for about $60, or you can build your own. Don't use coax to connect between the tuner output and the antenna lead. You'll be effectively inserting a large capacitance to ground. K8AC "gil" wrote in message ... My antenna setup is nothing but a random wire going from a tree/ tuner/ rig in the basement about 60-70 feet total, I know it could be better but its all I can get away with for the moment. The ground is a rod thru the bottom of the sump where is always wet and I feel is good for RF, I hook the end of that to the back of the random wire tuner. My concern is...the wire coming from window to tuner/rig is about 15 feet and due to placement I cant shorten it much more, Should I use a coax from window to rig? Or just leave it alone? BTW I use low power about 30-40 watts CW and the setup seems to work fairly well on most bands..just concerned about loss and RF inside the shack. Any input appreciated, and thanks for reading gil |
#3
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Gil,
If it's working okay, and it seems to be from what you've said, then I probably wouldn't bother to change the way you're feeding your antenna. There are probably several things that you could do to improve your system, but 15 feet of coax isn't going to make a lot of difference. But, the nice thing about it is that you could make the change and see for your self if there's any big differences (which will depend on the particular frequency). As for the RF exposure, at 40 watts, it just won't make any difference at all. 'Doc |
#4
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I'm surprised no one has suggested a coupling loop. Small loops are
often fed via a smaller loop placed inside the main loop, typically off center. The impedance match can be effected by adjusting the size and number of turns of the smaller loop. I believe one of Reg's programs helps with the design of these. Roy Lewallen, W7EL |
#5
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On Wed, 30 Jul 2003 11:05:42 -0700, Roy Lewallen wrote:
I'm surprised no one has suggested a coupling loop. Small loops are often fed via a smaller loop placed inside the main loop, typically off center. The impedance match can be effected by adjusting the size and number of turns of the smaller loop. I believe one of Reg's programs helps with the design of these. Roy Lewallen, W7EL I'm just curious. Roy? What the heck are you talking about? I mean, I can see you're talking about feeding a magloop, but what does that have to do with feeding a random wire from a basement? |
#6
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Oops. The reason it makes no sense is that I screwed up and posted it to
the wrong thread. Someone was asking about feeding a metal window frame, and that's what I intended it to refer to. I apologize for the goof and the confusion it caused. Roy Lewallen, W7EL Tim Conway wrote: On Wed, 30 Jul 2003 11:05:42 -0700, Roy Lewallen wrote: I'm surprised no one has suggested a coupling loop. Small loops are often fed via a smaller loop placed inside the main loop, typically off center. The impedance match can be effected by adjusting the size and number of turns of the smaller loop. I believe one of Reg's programs helps with the design of these. Roy Lewallen, W7EL I'm just curious. Roy? What the heck are you talking about? I mean, I can see you're talking about feeding a magloop, but what does that have to do with feeding a random wire from a basement? |
#7
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On Fri, 01 Aug 2003 11:23:54 -0700, Roy Lewallen wrote:
Oops. The reason it makes no sense is that I screwed up and posted it to the wrong thread. Someone was asking about feeding a metal window frame, and that's what I intended it to refer to. I apologize for the goof and the confusion it caused. Actually, I wasn't looking for an apology, but for a pointer back to the thread... it sounded interesting. Now that I know which thread, I must point out - wouldn't trying to run a window frame as a magloop be a big dummy load? I'd think he'd be better off loading it as a capacitative plate. The high currents in a magloop going around that aluminum, and crossing what are probably just butt joints, would dissipate nearly all the power as heat. Now, hanging a picture in a frame made of copper pipe and feeding that would be a whole new ball game. |
#8
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When I first started out, in amateur radio, my antenna was a random wire
about 75 feet long. About 15 ish feet was in the basement and the wire went though a hole drill through the window frame of the basement window. My antenna coupler was an L network. My tansmitter was a dx-60 and receiver was a gr-91, for the first 6 months and then a hr-10 for a few years after that. I did quite well with that arrangement. Larry ve3fxq "gil" wrote in message ... My antenna setup is nothing but a random wire going from a tree/ tuner/ rig in the basement about 60-70 feet total, I know it could be better but its all I can get away with for the moment. The ground is a rod thru the bottom of the sump where is always wet and I feel is good for RF, I hook the end of that to the back of the random wire tuner. My concern is...the wire coming from window to tuner/rig is about 15 feet and due to placement I cant shorten it much more, Should I use a coax from window to rig? Or just leave it alone? BTW I use low power about 30-40 watts CW and the setup seems to work fairly well on most bands..just concerned about loss and RF inside the shack. Any input appreciated, and thanks for reading gil |
#9
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When I first stated, I found an old roll of fence wire and ran it out the window. It was probably 50 feet long and I brought it right into the shack. I had an old crystal-controlled (7120 Khz and 3740 Khz) homebrew transmitter my dad built and a Realistic DX-100 (bad bandspread). This was in 1982 so better stuff was available, I just didn't have any money (I was 15). My dad had let his license lapse back in the 60's when he was a General. This transmitter was all he had left and the receiver was a Christmas gift. I used it for about two years and worked all around the world (upgraded the receiver after about 6 months). I have found that to an extent, patience and perseverance (and a good receiver) more than make up for high dollars. Patrick |
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