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"Michael Lawson" wrote in message ... "Dave" wrote in message ... I recently installed a makeshift antenna on my roof similar to the "temporary" one I have been using for a couple of years, but its performance is severely degraded (not quite as good as my whip antenna, by itself). Now I think I have found the problem, but want to check with those on the group to confirm my suspicions. I used RG59 coax in combination with 300-ohm/50 ohm baluns, but now find a source of information that says RG59 is 75-ohm, not 52 ohm like the guy at the parts depot told me. Which do I believe? The (young) guy who cut the cable for me, or the book on RF design that some people says is full of mistakes? What is the actual impedance of RG59 coax? RG-59/RG-6 is 75 ohm, and RG-58/RG-8x/RG-8 is 52 ohm. How long of a run do you have from the antenna to the receiver?? I'd suspect something more than just the coax if you've got severely degraded performance. What's the radio and the type of antenna you're using?? --Mike L. Thanks for the quick response, Mike! 65 feet of coax between the radio (DX-402/ATS-505) and the antenna (200 feet of 300 ohm twin-lead hidden along the ridge on the roof of the house.) And I don't think I would call it "severely" degraded, only slightly so. Only a little less than the old "temporary" antenna (60 feet of four strand copper wire thrown over the house.) Also, the new antenna is oriented primarily E/W while the "temporary" antenna was oriented primarily N/S, if that matters. Thanks again for the help. Dave |
Dave wrote: I recently installed a makeshift antenna on my roof similar to the "temporary" one I have been using for a couple of years, but its performance is severely degraded (not quite as good as my whip antenna, by itself). Now I think I have found the problem, but want to check with those on the group to confirm my suspicions. I used RG59 coax in combination with 300-ohm/50 ohm baluns, but now find a source of information that says RG59 is 75-ohm, not 52 ohm like the guy at the parts depot told me. Which do I believe? The (young) guy who cut the cable for me, or the book on RF design that some people says is full of mistakes? What is the actual impedance of RG59 coax? 75 ohms. dxAce Michigan USA |
"Dave" wrote in message ... I recently installed a makeshift antenna on my roof similar to the "temporary" one I have been using for a couple of years, but its performance is severely degraded (not quite as good as my whip antenna, by itself). Now I think I have found the problem, but want to check with those on the group to confirm my suspicions. I used RG59 coax in combination with 300-ohm/50 ohm baluns, but now find a source of information that says RG59 is 75-ohm, not 52 ohm like the guy at the parts depot told me. Which do I believe? The (young) guy who cut the cable for me, or the book on RF design that some people says is full of mistakes? What is the actual impedance of RG59 coax? RG-59/RG-6 is 75 ohm, and RG-58/RG-8x/RG-8 is 52 ohm. How long of a run do you have from the antenna to the receiver?? I'd suspect something more than just the coax if you've got severely degraded performance. What's the radio and the type of antenna you're using?? --Mike L. |
"dxAce" wrote in message ... Dave wrote: I recently installed a makeshift antenna on my roof similar to the "temporary" one I have been using for a couple of years, but its performance is severely degraded (not quite as good as my whip antenna, by itself). Now I think I have found the problem, but want to check with those on the group to confirm my suspicions. I used RG59 coax in combination with 300-ohm/50 ohm baluns, but now find a source of information that says RG59 is 75-ohm, not 52 ohm like the guy at the parts depot told me. Which do I believe? The (young) guy who cut the cable for me, or the book on RF design that some people says is full of mistakes? What is the actual impedance of RG59 coax? 75 ohms. dxAce Michigan USA Thanks. Noted. Dave |
"Dave" wrote in message ... "Michael Lawson" wrote in message ... "Dave" wrote in message ... I recently installed a makeshift antenna on my roof similar to the "temporary" one I have been using for a couple of years, but its performance is severely degraded (not quite as good as my whip antenna, by itself). Now I think I have found the problem, but want to check with those on the group to confirm my suspicions. I used RG59 coax in combination with 300-ohm/50 ohm baluns, but now find a source of information that says RG59 is 75-ohm, not 52 ohm like the guy at the parts depot told me. Which do I believe? The (young) guy who cut the cable for me, or the book on RF design that some people says is full of mistakes? What is the actual impedance of RG59 coax? RG-59/RG-6 is 75 ohm, and RG-58/RG-8x/RG-8 is 52 ohm. How long of a run do you have from the antenna to the receiver?? I'd suspect something more than just the coax if you've got severely degraded performance. What's the radio and the type of antenna you're using?? --Mike L. Thanks for the quick response, Mike! 65 feet of coax between the radio (DX-402/ATS-505) and the antenna (200 feet of 300 ohm twin-lead hidden along the ridge on the roof of the house.) And I don't think I would call it "severely" degraded, only slightly so. Only a little less than the old "temporary" antenna (60 feet of four strand copper wire thrown over the house.) Also, the new antenna is oriented primarily E/W while the "temporary" antenna was oriented primarily N/S, if that matters. The orientation does matter if you're not using a vertical, but the first thing that popped into my mind was overloading the ATS-505 with 200 feet of antenna wire. The longest I've ever run into my old DX-440/ATS-803A was about 40-50 feet, and while I never overloaded it, I've never tried anything close to 200 feet into it. But yeah, the E/W orientation will work well for stations that are north or south of you (like tropical band stuff), but not so good for hearing things east or west of you (like from Europe or Africa or -depending on where you're at- relays like Sackville). If you can get into the attic, try running some of the same antenna wire north/south and see if you get the same response. --Mike L. |
" Thanks for the quick response, Mike! 65 feet of coax between the radio (DX-402/ATS-505) and the antenna (200 feet of 300 ohm twin-lead hidden along the ridge on the roof of the house.) And I don't think I would call it "severely" degraded, only slightly so. Only a little less than the old "temporary" antenna (60 feet of four strand copper wire thrown over the house.) Also, the new antenna is oriented primarily E/W while the "temporary" antenna was oriented primarily N/S, if that matters. The orientation does matter if you're not using a vertical, but the first thing that popped into my mind was overloading the ATS-505 with 200 feet of antenna wire. The longest I've ever run into my old DX-440/ATS-803A was about 40-50 feet, and while I never overloaded it, I've never tried anything close to 200 feet into it. But yeah, the E/W orientation will work well for stations that are north or south of you (like tropical band stuff), but not so good for hearing things east or west of you (like from Europe or Africa or -depending on where you're at- relays like Sackville). Unless the antenna is a approx. 1/2 wavelength up or higher ( at tropical band= 150' or so) the end nulls fill in making even horizontal antennas near omni. Guess my question is, how are you connecting the twin lead- if simply connecting it to the balun, you have little more than a 300 Ohm transmission line, not an antenna. In fact, if the baluns were perfectly balanced, and the twin lead clear of metallic objects ( which would unbalance it) you would theoretically get zero signal. Dale W4OP |
"Dale Parfitt" wrote in message news:25Krd.8148$1z5.1438@trnddc06... " Thanks for the quick response, Mike! 65 feet of coax between the radio (DX-402/ATS-505) and the antenna (200 feet of 300 ohm twin-lead hidden along the ridge on the roof of the house.) And I don't think I would call it "severely" degraded, only slightly so. Only a little less than the old "temporary" antenna (60 feet of four strand copper wire thrown over the house.) Also, the new antenna is oriented primarily E/W while the "temporary" antenna was oriented primarily N/S, if that matters. The orientation does matter if you're not using a vertical, but the first thing that popped into my mind was overloading the ATS-505 with 200 feet of antenna wire. The longest I've ever run into my old DX-440/ATS-803A was about 40-50 feet, and while I never overloaded it, I've never tried anything close to 200 feet into it. But yeah, the E/W orientation will work well for stations that are north or south of you (like tropical band stuff), but not so good for hearing things east or west of you (like from Europe or Africa or -depending on where you're at- relays like Sackville). Unless the antenna is a approx. 1/2 wavelength up or higher ( at tropical band= 150' or so) the end nulls fill in making even horizontal antennas near omni. Guess my question is, how are you connecting the twin lead- if simply connecting it to the balun, you have little more than a 300 Ohm transmission line, not an antenna. In fact, if the baluns were perfectly balanced, and the twin lead clear of metallic objects ( which would unbalance it) you would theoretically get zero signal. Dale W4OP Hey Dale, thanks for jumping in. Well, get the calculator out. The two freqs of interest to me are 9335 KHz and 11710 KHz, so I am going to work with something between those two numbers (10 MHz). If I am correct, 10 Mhz has a wavelength of 30 meters, which works out to about 98 feet. And I am working with 200 feet. (Maybe I should call this a long-wire antenna?) Question for you: what is an end null? And yes, I simply connected the 300-ohm to the baluns to the coax, to another balun, and then a third that plugs into my external antenna socket. And I a definetly getting a signal. Whatcha think? Dave |
Dave wrote: "Dale Parfitt" wrote in message news:25Krd.8148$1z5.1438@trnddc06... " Thanks for the quick response, Mike! 65 feet of coax between the radio (DX-402/ATS-505) and the antenna (200 feet of 300 ohm twin-lead hidden along the ridge on the roof of the house.) And I don't think I would call it "severely" degraded, only slightly so. Only a little less than the old "temporary" antenna (60 feet of four strand copper wire thrown over the house.) Also, the new antenna is oriented primarily E/W while the "temporary" antenna was oriented primarily N/S, if that matters. The orientation does matter if you're not using a vertical, but the first thing that popped into my mind was overloading the ATS-505 with 200 feet of antenna wire. The longest I've ever run into my old DX-440/ATS-803A was about 40-50 feet, and while I never overloaded it, I've never tried anything close to 200 feet into it. But yeah, the E/W orientation will work well for stations that are north or south of you (like tropical band stuff), but not so good for hearing things east or west of you (like from Europe or Africa or -depending on where you're at- relays like Sackville). Unless the antenna is a approx. 1/2 wavelength up or higher ( at tropical band= 150' or so) the end nulls fill in making even horizontal antennas near omni. Guess my question is, how are you connecting the twin lead- if simply connecting it to the balun, you have little more than a 300 Ohm transmission line, not an antenna. In fact, if the baluns were perfectly balanced, and the twin lead clear of metallic objects ( which would unbalance it) you would theoretically get zero signal. Dale W4OP Hey Dale, thanks for jumping in. Well, get the calculator out. The two freqs of interest to me are 9335 KHz and 11710 KHz, so I am going to work with something between those two numbers (10 MHz). If I am correct, 10 Mhz has a wavelength of 30 meters, which works out to about 98 feet. And I am working with 200 feet. (Maybe I should call this a long-wire antenna?) Question for you: what is an end null? And yes, I simply connected the 300-ohm to the baluns to the coax, to another balun, and then a third that plugs into my external antenna socket. And I a definetly getting a signal. Whatcha think? 300 ohm to the baluns?, then to the coax, to another balun? then to a third balun? I'm going hmmmmmmmmmmmmmmmmmmmmmm. dxAce Michigan USA |
"dxAce" wrote in message ... Dave wrote: "Dale Parfitt" wrote in message news:25Krd.8148$1z5.1438@trnddc06... " Thanks for the quick response, Mike! 65 feet of coax between the radio (DX-402/ATS-505) and the antenna (200 feet of 300 ohm twin-lead hidden along the ridge on the roof of the house.) And I don't think I would call it "severely" degraded, only slightly so. Only a little less than the old "temporary" antenna (60 feet of four strand copper wire thrown over the house.) Also, the new antenna is oriented primarily E/W while the "temporary" antenna was oriented primarily N/S, if that matters. The orientation does matter if you're not using a vertical, but the first thing that popped into my mind was overloading the ATS-505 with 200 feet of antenna wire. The longest I've ever run into my old DX-440/ATS-803A was about 40-50 feet, and while I never overloaded it, I've never tried anything close to 200 feet into it. But yeah, the E/W orientation will work well for stations that are north or south of you (like tropical band stuff), but not so good for hearing things east or west of you (like from Europe or Africa or -depending on where you're at- relays like Sackville). Unless the antenna is a approx. 1/2 wavelength up or higher ( at tropical band= 150' or so) the end nulls fill in making even horizontal antennas near omni. Guess my question is, how are you connecting the twin lead- if simply connecting it to the balun, you have little more than a 300 Ohm transmission line, not an antenna. In fact, if the baluns were perfectly balanced, and the twin lead clear of metallic objects ( which would unbalance it) you would theoretically get zero signal. Dale W4OP Hey Dale, thanks for jumping in. Well, get the calculator out. The two freqs of interest to me are 9335 KHz and 11710 KHz, so I am going to work with something between those two numbers (10 MHz). If I am correct, 10 Mhz has a wavelength of 30 meters, which works out to about 98 feet. And I am working with 200 feet. (Maybe I should call this a long-wire antenna?) Question for you: what is an end null? And yes, I simply connected the 300-ohm to the baluns to the coax, to another balun, and then a third that plugs into my external antenna socket. And I a definetly getting a signal. Whatcha think? 300 ohm to the baluns?, then to the coax, to another balun? then to a third balun? I'm going hmmmmmmmmmmmmmmmmmmmmmm. dxAce Michigan USA And what are you thinking, while going hmmmmmmm... :) I don't have your experience. Thanks, Dave |
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