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#1
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Counterpoise wire length. I've heard that it should be 1/4 wave, and then again I've
heard it should be 1/2. Which is correct, or will they both work? -- SeeYaa ![]() This is YOUR futu http://halturnershow.com/aztlan_caps.wmv - |
#2
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Counterpoise to what?
You need to describe what are you trying "counterpoison". Yuri, K3BU "Harbin" wrote in message ... Counterpoise wire length. I've heard that it should be 1/4 wave, and then again I've heard it should be 1/2. Which is correct, or will they both work? -- SeeYaa ![]() This is YOUR futu http://halturnershow.com/aztlan_caps.wmv - |
#3
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![]() Harbin wrote: Counterpoise wire length. I've heard that it should be 1/4 wave, and then again I've heard it should be 1/2. Which is correct, or will they both work? The lowest impedance presented by a single counterpoise wire is when the counterpoise is resonant and 1/4 wl long electrically. When a single counterpoise wire is near 1/2 wl long and resonant, it has a very high end impedance. If the counterpoise is under a dipole or some other antenna just to isolate it from ground losses, a 1/2 wl long counterpoise or longer is best. If the counterpoise is used as a termination to allow forceing current into a Marconi antenna or an end-fed antenna, or used to provide a ground path for unwanted currents, it is best if it is 1/4 wl long. More counterpoise wires are always better, because the more you use the less critical length is and the lower loss is. There is of course a point where more won't help. With 1/4 wl wires, 50 or so placed radially are near perfect. Adding more won't make a noticeable difference. Once the counterpoise wires are .025 to .05 wavelengths apart at the widest points, adding more will generally not help. I use 100 200 foot long wires on one of my 160 meter verticals. On my other verticals I have 1/4 wl radials, and once I reached 40-50 radials adding more made no measureable difference at all. 73 Tom |
#4
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Say I was using a short wave receiver, and I'm on the second floor, without a good
ground. I would be running a long wire. Would it help to cut a counterpoise for the bands I wish to listen to, a single wire for each band? Would it be 1/4, or 1/2 wave? -- SeeYaa ![]() This is YOUR futu http://halturnershow.com/aztlan_caps.wmv - "Yuri Blanarovich" wrote in message news ![]() Counterpoise to what? You need to describe what are you trying "counterpoison". Yuri, K3BU |
#5
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Looks like I'm looking for a 1/4 wave. Thanks
-- SeeYaa ![]() This is YOUR futu http://halturnershow.com/aztlan_caps.wmv - wrote in message ps.com... Harbin wrote: Counterpoise wire length. I've heard that it should be 1/4 wave, and then again I've heard it should be 1/2. Which is correct, or will they both work? The lowest impedance presented by a single counterpoise wire is when the counterpoise is resonant and 1/4 wl long electrically. When a single counterpoise wire is near 1/2 wl long and resonant, it has a very high end impedance. If the counterpoise is under a dipole or some other antenna just to isolate it from ground losses, a 1/2 wl long counterpoise or longer is best. If the counterpoise is used as a termination to allow forceing current into a Marconi antenna or an end-fed antenna, or used to provide a ground path for unwanted currents, it is best if it is 1/4 wl long. More counterpoise wires are always better, because the more you use the less critical length is and the lower loss is. There is of course a point where more won't help. With 1/4 wl wires, 50 or so placed radially are near perfect. Adding more won't make a noticeable difference. Once the counterpoise wires are .025 to .05 wavelengths apart at the widest points, adding more will generally not help. I use 100 200 foot long wires on one of my 160 meter verticals. On my other verticals I have 1/4 wl radials, and once I reached 40-50 radials adding more made no measureable difference at all. 73 Tom |
#6
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If you are using long wire for different bands, you can tap to your water
pipe for ground, or metal frame of the screen door, or most likely your RX is already "grounded" through its AC PS. You can try through capacitor of about 10000 uuF/1kV from your RX ground to your ground pin the AC outlet. Alternative I used for antenna when in restricted area, just run wire from ant terminal on RX through capacitor of about 10 k rated at least at 3000V to one of the connections in AC outlet, well insulated and mounted in AC plug. Yuri, K3BU "Harbin" wrote in message ... Say I was using a short wave receiver, and I'm on the second floor, without a good ground. I would be running a long wire. Would it help to cut a counterpoise for the bands I wish to listen to, a single wire for each band? Would it be 1/4, or 1/2 wave? -- SeeYaa ![]() |
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