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#1
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Low Noise Receiving antennas
I live in a neighborhood that as the years have gone on
has added a number of new homes. This has increased the electrical "noise" for me where S1 or S2 on 80 meters 6-8 yrs ago is now S7 to S9. At this point in time I don't have the room for a K9AY setup. I can only "dream" of a beverage. I have a Timewave ANC-4 which works very well on 40 meters as I can null out ALL the "noise". Not so on 80 meters as it only knocks it down 2 S Units. At best I have an S-6 noise level. This leads me to believe that I need a separate sensing antenna for 80 meters. Anyone have any ideas for this problem? Is this thinking correct? I have been looking at low noise receiving loops and other low noise antennas. Wellbrook at http://www.wellbrook.uk.com/ seems to have some interresting possibilities, but some of the reviews I have read have made me hesistant to purchase any of their products. What I need is some serious input from anyone who has any experience and knowledge in dealing with low band noise issues. As I am now space limited due to all the new neighbors any solution would need to take this into consideration. TIA |
#2
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Low Noise Receiving antennas
Tony Giacometti wrote:
This leads me to believe that I need a separate sensing antenna for 80 meters. Anyone have any ideas for this problem? Is this thinking correct? I would start with a T2FD. It's simple to build and cheap. The only expensive part is the loading resistor which for receiving only can be a 1/4 watt. A balun would help, for receiving you can use a TV balun. I have been looking at low noise receiving loops and other low noise antennas. Wellbrook at http://www.wellbrook.uk.com/ seems to have some interresting possibilities, but some of the reviews I have read have made me hesistant to purchase any of their products. Each one has its benefits and its costs. How much you want to spend on an antenna is a personal decisison and unfortunately, you can't tell if it really does anything for you until you have bought it. An other possibility is to use an active antenna and mount it high up. Geoff. -- Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM IL Voice: (07)-7424-1667 U.S. Voice: 1-215-821-1838 Visit my 'blog at http://geoffstechno.livejournal.com/ |
#3
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Low Noise Receiving antennas
Geoffrey S. Mendelson wrote:
Tony Giacometti wrote: This leads me to believe that I need a separate sensing antenna for 80 meters. Anyone have any ideas for this problem? Is this thinking correct? I would start with a T2FD. It's simple to build and cheap. The only expensive part is the loading resistor which for receiving only can be a 1/4 watt. A balun would help, for receiving you can use a TV balun. I am confused..............are you suggesting I use a T2FD for a noise sensing antenna to be used with my ANC-4? Or should I take down my vertical transmitting antenna and replace it with a T2FD? The vertical I use works extremely well for transmitting, its not going away. What I need is a solution to the noise. Which would be a low noise receive only antenna of some type. I have been looking at low noise receiving loops and other low noise antennas. Wellbrook at http://www.wellbrook.uk.com/ seems to have some interresting possibilities, but some of the reviews I have read have made me hesistant to purchase any of their products. Each one has its benefits and its costs. How much you want to spend on an antenna is a personal decisison and unfortunately, you can't tell if it really does anything for you until you have bought it. I do believe that any antenna's performance is entirely dependent on the environment its in. An other possibility is to use an active antenna and mount it high up. any suggestions as to which one I might use? Geoff. |
#4
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Low Noise Receiving antennas
On Oct 11, 1:38 pm, Tony Giacometti wrote:
I live in a neighborhood that as the years have gone on has added a number of new homes. This has increased the electrical "noise" for me where S1 or S2 on 80 meters 6-8 yrs ago is now S7 to S9. At this point in time I don't have the room for a K9AY setup. I can only "dream" of a beverage. I have a Timewave ANC-4 which works very well on 40 meters as I can null out ALL the "noise". Not so on 80 meters as it only knocks it down 2 S Units. At best I have an S-6 noise level. This leads me to believe that I need a separate sensing antenna for 80 meters. Anyone have any ideas for this problem? Is this thinking correct? I have been looking at low noise receiving loops and other low noise antennas. Wellbrook athttp://www.wellbrook.uk.com/seems to have some interresting possibilities, but some of the reviews I have read have made me hesistant to purchase any of their products. What I need is some serious input from anyone who has any experience and knowledge in dealing with low band noise issues. As I am now space limited due to all the new neighbors any solution would need to take this into consideration. TIA What kind of sense antenna are you currently using? I use an active whip as a sense antenna (specifically, an H-800 "Skymatch" antenna) and it enables me to squash *any* noise on 80 meters using my ANC-4. |
#5
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Low Noise Receiving antennas
Tony Giacometti wrote:
I am confused..............are you suggesting I use a T2FD for a noise sensing antenna to be used with my ANC-4? Or should I take down my vertical transmitting antenna and replace it with a T2FD? Neither. I was suggesting (and obviously not very well) that you use it as a receiving antenna. It's very low noise. It makes a good transmitting antenna too, but you need to have a big enough balun and termination resistor to handle the power. Geoff. -- Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM IL Voice: (07)-7424-1667 U.S. Voice: 1-215-821-1838 Visit my 'blog at http://geoffstechno.livejournal.com/ |
#6
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Low Noise Receiving antennas
Steve wrote:
On Oct 11, 1:38 pm, Tony Giacometti wrote: I live in a neighborhood that as the years have gone on has added a number of new homes. This has increased the electrical "noise" for me where S1 or S2 on 80 meters 6-8 yrs ago is now S7 to S9. At this point in time I don't have the room for a K9AY setup. I can only "dream" of a beverage. I have a Timewave ANC-4 which works very well on 40 meters as I can null out ALL the "noise". Not so on 80 meters as it only knocks it down 2 S Units. At best I have an S-6 noise level. This leads me to believe that I need a separate sensing antenna for 80 meters. Anyone have any ideas for this problem? Is this thinking correct? I have been looking at low noise receiving loops and other low noise antennas. Wellbrook athttp://www.wellbrook.uk.com/seems to have some interresting possibilities, but some of the reviews I have read have made me hesistant to purchase any of their products. What I need is some serious input from anyone who has any experience and knowledge in dealing with low band noise issues. As I am now space limited due to all the new neighbors any solution would need to take this into consideration. TIA What kind of sense antenna are you currently using? I use an active whip as a sense antenna (specifically, an H-800 "Skymatch" antenna) and it enables me to squash *any* noise on 80 meters using my ANC-4. I use a small dipole like antenna where one half is at 45 degrees the feed point is a few inches above ground and the other side runs paralle to ground about 1-2 inches above ground. I think the whole sense antenna is about 6 ft long and runs in a straight line. I will look up the H-800 on the web. Did you try various antennas and configurations before you settled on the H-800? What made you decide to go with the H-800? I tried different "antennas" and configurations, for this location this has worked out the best that I have found. I do realize there could be a zazillion different antennas and configurations. |
#7
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Low Noise Receiving antennas
Geoffrey S. Mendelson wrote:
Tony Giacometti wrote: Or should I take down my vertical transmitting antenna and replace it with a T2FD? Neither. I was suggesting (and obviously not very well) that you use it as a receiving antenna. It's very low noise. It makes a good transmitting antenna too, but you need to have a big enough balun and termination resistor to handle the power. This could be a very interesting experiment. Try the T2FD but in steps. 1. Ordinary horizontal single-wire dipole 2. Ordinary horizontal folded dipole 3. T2FD Reporting the noise on those three configurations vs the vertical would be of wide interest. -- 73, Cecil http://www.w5dxp.com |
#8
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Low Noise Receiving antennas
Geoffrey S. Mendelson wrote:
Tony Giacometti wrote: I am confused..............are you suggesting I use a T2FD for a noise sensing antenna to be used with my ANC-4? Or should I take down my vertical transmitting antenna and replace it with a T2FD? Neither. I was suggesting (and obviously not very well) that you use it as a receiving antenna. It's very low noise. It makes a good transmitting antenna too, but you need to have a big enough balun and termination resistor to handle the power. Geoff. Your suggestion is a good one. I found some construction plans, all I need is the stuff to build it with. I think it would make an excellent sense antenna, but won't know until I try it to be sure. Any idea if it shows any directivity? |
#9
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Low Noise Receiving antennas
Cecil Moore wrote:
Geoffrey S. Mendelson wrote: Tony Giacometti wrote: Or should I take down my vertical transmitting antenna and replace it with a T2FD? Neither. I was suggesting (and obviously not very well) that you use it as a receiving antenna. It's very low noise. It makes a good transmitting antenna too, but you need to have a big enough balun and termination resistor to handle the power. This could be a very interesting experiment. Try the T2FD but in steps. 1. Ordinary horizontal single-wire dipole 2. Ordinary horizontal folded dipole 3. T2FD Reporting the noise on those three configurations vs the vertical would be of wide interest. well, I already use a shortened dipole which has one leg at 45 degrees (the end is somewhere between 2.5 to 4 ft high, I have not measured it) to the feed point that is about 2 to 3 inches off the ground and the other leg is about 1 to 2 inches off the ground. I don't use it directly into the receiver, I suppose I could, but I use the Timewave ANC-4 for reducing noise and its my noise sense antenna. Obviously this one as I mentioned works extremely well on 40 meters, I can null out all noise, the S meter lays flat on S1, but the 80 meter performance is poor. I would like to try the other antennas you mentioned as sense antennas, the problem is do I go full size on the folded dipole? I think I need to go full size with the T2FD in order to get it to work correctly. How high above ground do I need to get it? |
#10
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Low Noise Receiving antennas
On Oct 11, 2:37 pm, Tony Giacometti wrote:
Steve wrote: On Oct 11, 1:38 pm, Tony Giacometti wrote: I live in a neighborhood that as the years have gone on has added a number of new homes. This has increased the electrical "noise" for me where S1 or S2 on 80 meters 6-8 yrs ago is now S7 to S9. At this point in time I don't have the room for a K9AY setup. I can only "dream" of a beverage. I have a Timewave ANC-4 which works very well on 40 meters as I can null out ALL the "noise". Not so on 80 meters as it only knocks it down 2 S Units. At best I have an S-6 noise level. This leads me to believe that I need a separate sensing antenna for 80 meters. Anyone have any ideas for this problem? Is this thinking correct? I have been looking at low noise receiving loops and other low noise antennas. Wellbrook athttp://www.wellbrook.uk.com/seemsto have some interresting possibilities, but some of the reviews I have read have made me hesistant to purchase any of their products. What I need is some serious input from anyone who has any experience and knowledge in dealing with low band noise issues. As I am now space limited due to all the new neighbors any solution would need to take this into consideration. TIA What kind of sense antenna are you currently using? I use an active whip as a sense antenna (specifically, an H-800 "Skymatch" antenna) and it enables me to squash *any* noise on 80 meters using my ANC-4. I use a small dipole like antenna where one half is at 45 degrees the feed point is a few inches above ground and the other side runs paralle to ground about 1-2 inches above ground. I think the whole sense antenna is about 6 ft long and runs in a straight line. I will look up the H-800 on the web. Did you try various antennas and configurations before you settled on the H-800? What made you decide to go with the H-800? I tried different "antennas" and configurations, for this location this has worked out the best that I have found. I do realize there could be a zazillion different antennas and configurations.- Hide quoted text - - Show quoted text - I tried lots and lots of different sense antennas and got varying results. The H-800 gives me the best results from among all the sense antennas I've tried, though of course this could be a function of the particular kinds of noise present at my QTH. I will say this. Because I live in an urban area it's been my aim to defeat RFI in every way possible. I use one of the Wellbrook loops and that helps, but nothing has been as big a help as the ANC-4 WHEN MATCHED with the right sense antenna. Part of me suspects that the ideal setup, at least for me, would involve having a couple of different active whips to switch back and forth between. I think the H-800 does well on 80 meters because it's quite sensitive there. However, it's quite a bit less sensitive on, say, 20 meters and I'll bet I'd get better results using a different active whip, or perhaps a wire, on higher frequencies. |
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