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Post by Night Ranger on Mar 7, 2012 21:36:50 GMT -5
I am currently building a 6 element curtain array for the CB band. On 27 MHz it uses six .6 wavelength elements with .6 wavelength spacing between the top and middle elements and .6 wavelength spacing between the middle and bottom elements. Below is the EZNEC plot for 27.205 MHz. The gain is slightly higher than predicted by EZNEC as I only have the free trail version of EZNEC, and as a result I cannot assign enough segments to accurately compute the antenna gain. www.shadowstorm.com/images/6ElementCurtainArray.jpgThis picture below shows the radiation pattern of the antenna when looking down from above the antenna towards the ground (free space) www.shadowstorm.com/images/6ElementFreeSpacePattern.jpgSo far I have the antenna about 90% built. I laid it out in the grass to put on the supporting ropes and this puppy is big. The antenna is 43 feet 6 inches tall and 43 feet 6 inches wide. It is a monster. I still have to shoot the supporting ropes through the trees. I may have to cut a few tree limbs as well to make enough clear space for it. The antenna will be aimed East and West as it is a bi-directional antenna. I am using equal length 450 ladder line feeders to each driven element pair from a central tie in point, so the antenna is a multi-band antenna. At 10 MHz it is similar to a dipole. The gain increases as you go up in frequency in a steady upward slope, and the gain maxes out around 29 MHz and then quickly trails off. I'll post a picture/video of the antenna once it is up in the air along with EZNEC plots for the ham bands from 10 MHz up to 29 MHz. This antenna should out perform my Lazy H antennas particularly for DX stations at 2000 miles away and further due to the lower angle of radiation and higher gain over a dipole. Night Ranger |
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Sandbagger
Administrator/The Boss 
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Post by Sandbagger on Mar 8, 2012 7:19:23 GMT -5
I am currently building a 6 element curtain array for the CB band. On 27 MHz it uses six .6 wavelength elements with .6 wavelength spacing between the top and middle elements and .6 wavelength spacing between the middle and bottom elements. Below is the EZNEC plot for 27.205 MHz. The gain is slightly higher than predicted by EZNEC as I only have the free trail version of EZNEC, and as a result I cannot assign enough segments to accurately compute the antenna gain. www.shadowstorm.com/images/6ElementCurtainArray.jpgThis picture below shows the radiation pattern of the antenna when looking down from above the antenna towards the ground (free space) www.shadowstorm.com/images/6ElementFreeSpacePattern.jpgSo far I have the antenna about 90% built. I laid it out in the grass to put on the supporting ropes and this puppy is big. The antenna is 43 feet 6 inches tall and 43 feet 6 inches wide. It is a monster. I still have to shoot the supporting ropes through the trees. I may have to cut a few tree limbs as well to make enough clear space for it. The antenna will be aimed East and West as it is a bi-directional antenna. I am using equal length 450 ladder line feeders to each driven element pair from a central tie in point, so the antenna is a multi-band antenna. At 10 MHz it is similar to a dipole. The gain increases as you go up in frequency in a steady upward slope, and the gain maxes out around 29 MHz and then quickly trails off. I'll post a picture/video of the antenna once it is up in the air along with EZNEC plots for the ham bands from 10 MHz up to 29 MHz. This antenna should out perform my Lazy H antennas particularly for DX stations at 2000 miles away and further due to the lower angle of radiation nad higher gain over a dipole. Night Ranger Interesting to see how this antenna works compared to the lazy-H. I wish I had your real estate for building antennas...... |
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Post by Night Ranger on Mar 8, 2012 8:45:47 GMT -5
Interesting to see how this antenna works compared to the lazy-H. I wish I had your real estate for building antennas...... For skip stations 2000 miles away or more this antenna should be superior to a single Lazy H not only because of the higher gain, but because of the lower angle of radiation. From South Carolina to your location in Pennsylvania is between 600 and 700 miles. The Lazy H actually has a better angle of radiation for short skip like that. I'd be better off with two phased Lazy H antennas when talking to Pennsylvania. The actual gain of the 6 element curtain array over a dipole in this configuration is probably somewhere around 8.5 dbd gain. A screen reflector would add another 3 or 4 db gain to the array. Since the broadside lobes are much narrower than the Lazy H I should be hearing less interference from Mexico. The negative is I can use my west facing Lazy H to talk to Australia and New Zealand. The 6 element curtain array will probably cut that part of the world out. The current west facing Lazy H already gives me daily S9 signal reports out of California, Arizona, Utah, Washington State, Idaho and Hawaii with 200 watts on sideband. I'm looking forward to seeing what the 6 element curtain array will do. If the 6 element curtain array works really well I may have to aim one towards Europe as well. Night Ranger |
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Post by cbrown on Mar 8, 2012 9:53:06 GMT -5
Very impressive work!
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Post by Night Ranger on Mar 15, 2012 18:44:13 GMT -5
Crack! Whoooooosh! Thud!
Well the big cottonwood tree that prevented me from having enough space to string up my 6 element curtain array with .6 wavelength elements and .6 wavelength element spacing came crashing to the ground today. It was not a small tree. It did not fall exactly where I wanted it, but where it landed was the next best spot. Unfortunately it tore through my Lazy H antenna facing Pennsylvania on the way down. Oh well. Now I have some new incentive to build an 8 element co-phased Lazy H, and aim it towards Pennsylvania.
I was a little worried when the tree started leaning in the wrong direction, but with the help of some 300+ pound test ropes, a few desperate pleas to the Almighty Himself, and three come-a-longs I was able to manage a suitable resting place for the cottonwood tree.
I currently have the 6 element curtain array hanging between the trees facing west, but I have not hooked up the ladder line going back to the shack yet. After half a day of messing with it I was ready for a beer and some relaxation. If all goes well I should be lighting up S meters on the west coast by Friday evening or Saturday morning with what may be the CB bands only 6 element curtain array in existence.
Night Ranger
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Sandbagger
Administrator/The Boss
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Post by Sandbagger on Mar 16, 2012 6:44:05 GMT -5
Crack! Whoooooosh! Thud! Well the big cottonwood tree that prevented me from having enough space to string up my 6 element curtain array with .6 wavelength elements and .6 wavelength element spacing came crashing to the ground today. It was not a small tree. It did not fall exactly where I wanted it, but where it landed was the next best spot. Unfortunately it tore through my Lazy H antenna facing Pennsylvania on the way down. Oh well. Now I have some new incentive to build an 8 element co-phased Lazy H, and aim it towards Pennsylvania. I was a little worried when the tree started leaning in the wrong direction, but with the help of some 300+ pound test ropes, a few desperate pleas to the Almighty Himself, and three come-a-longs I was able to manage a suitable resting place for the cottonwood tree. I currently have the 6 element curtain array hanging between the trees facing west, but I have not hooked up the ladder line going back to the shack yet. After half a day of messing with it I was ready for a beer and some relaxation. If all goes well I should be lighting up S meters on the west coast by Friday evening or Saturday morning with what may be the CB bands only 6 element curtain array in existence. Night Ranger As long as it works, that's all that matters. Looks like you might have a new career as a lumberjack. ;D But get that Lazy-H fixed soon (or replaced with something better), the summer E-skip is right around the corner, and we're hoping to have you check into CRR on Wednesday nights and on 10 meters Sunday nights again. |
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Post by Night Ranger on Mar 16, 2012 7:33:09 GMT -5
As long as it works, that's all that matters. Looks like you might have a new career as a lumberjack. ;D But get that Lazy-H fixed soon (or replaced with something better), the summer E-skip is right around the corner, and we're hoping to have you check into CRR on Wednesday nights and on 10 meters Sunday nights again. I can always use the Lazy H that was facing west to replace the one that was facing Pennsylvania. The support ropes for the PA facing Lazy H are still hanging in the air. Night Ranger |
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Post by cbrown on Mar 16, 2012 12:07:52 GMT -5
Now I have some new incentive to build an 8 element co-phased Lazy H, and aim it towards Pennsylvania. That should move a S Meter or two. ;D |
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Post by Night Ranger on Mar 17, 2012 10:56:21 GMT -5
Woohoo! My new .6 wavelength six element curtain array is up in the air and working. It is too early to really call it a success, but my first contact was favorable. My first contact was to 306 in New Mexico. He said when I did an A/B comparison between my horizontal 1/2 wave dipole and my new horizontal .6 wavelength six element curtain array (HR 32 array) that the curtain array was putting in a stronger signal than the dipole by 8 to 10 db! The curtain array does have a height advantage over the dipole, but still that was a nice thing to hear. I am also hearing reduced Hispanic signals from the south as anticipated, and signals from the west that are sometimes barely audible on the dipole jump out of the static when I switch to the six element curtain array.
Later in the day I got a second signal report from a station "1212" in Hawaii. He heard me call on 38 LSB, and then we dropped to 37 LSB for an A/B signal test. The station in Hawaii said on his Yaesu FT-757 I was putting an S3 to S4 on my dipole, and on the six element curtain array I was putting between an S8 and an S9. I was using 200 watts out from my D&A Raider with the 22jg6a tubes for all signal test.
I'd like to get the curtain array a little higher as the bottom two elements are not a full half wave off the ground at this point. They are about 12 feet off the ground. The best performance should occur with the bottom two elements at least a half wave off the ground.
Night Ranger
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Sandbagger
Administrator/The Boss
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Post by Sandbagger on Mar 17, 2012 19:13:31 GMT -5
Woohoo! My new .6 wavelength six element curtain array is up in the air and working. It is too early to really call it a success, but my first contact was favorable. My first contact was to 306 in New Mexico. He said when I did an A/B comparison between my horizontal 1/2 wave dipole and my new horizontal .6 wavelength six element curtain array (HR 32 array) that the curtain array was putting in a stronger signal than the dipole by 8 to 10 db! The curtain array does have a height advantage over the dipole, but still that was a nice thing to hear. I am also hearing reduced Hispanic signals from the south as anticipated, and signals from the west that are sometimes barely audible on the dipole jump out of the static when I switch to the six element curtain array. Later in the day I got a second signal report from a station "1212" in Hawaii. He heard me called on 38 LSB, and then we dropped to 37 LSB for an A/B signal test. The station in Hawaii said on his Yaesu FT-757 I was putting an S3 to S4 on my dipole, and on the six element curtain array I was putting between an S8 and an S9. I was using 200 watts out from my D&A Raider with the 22jg6a tubes for all signal test. I'd like to get the curtain array a little higher as the bottom two elements are not a full half wave off the ground at this point. They are about 12 feet off the ground. The best performance should occur with the bottom two elements at least a half wave off the ground. Night Ranger Sounds like preliminary reports are favorable. Raising the antenna up should lower the angle of radiation, which would yield better results for long path F-skip. |
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Post by Night Ranger on Mar 17, 2012 20:27:59 GMT -5
Sounds like preliminary reports are favorable. Raising the antenna up should lower the angle of radiation, which would yield better results for long path F-skip. I did alot of A/B comparisons between the 1/2 wave dipole and the 6 element curtain array on receive as well. According to the EZNEC antenna modeling software the beam width of the 6 element curtain array should be about 30 degrees. It is definitely narrower than the Lazy H in the real world. I noticed the following signal differences today for various locations I was listening to from my location near Charleston, South Carolina; 1) Mexico City, Mexico - The dipole and the 6 element array were about the same 2) Arizona, New Mexico and Southern California - The 6 element curtain array was the clear winner by several S units. 3) Hawaii - The 6 element curtain array was the clear winner by several S units 4) Washington State and Montana - The dipole had the stronger received signal. It appears the 6 element curtain array is aimed across the U.S. Southwest, Northern Mexico and out in to the Pacific. The U.S. Northwest was attenuated by the curtain array verses the dipole. I checked the compass and the curtain array is aimed 6 degrees north of west. To get a more central US coverage and more rejection of Mexico I am going to aim the antenna more north hoping for about 11 to 12 degrees north of west. Interestingly Australia is also noticeably stronger on the 6 element curtain array even though it is not aimed at Australia. I am guessing that is because the 6 element curtain array has a much lower angle of radiation than the 1/2 wave dipole. I also received an S2 to S3 signal report from a mobile in Hawaii while on the 6 element curtain array. Night Ranger |
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Post by Night Ranger on Mar 18, 2012 20:32:58 GMT -5
I repositioned the 6 element curtain array to about 17 to 21 degrees north of west. There was not much skip in today, but when southern California came in I was still getting favorable reports. I did an A/B test with 167 Ron in southern California and he said the horizontal dipole was putting S5 on him and the 6 element curtain array way putting S9 on him. I was using 200 watts output from the D&A Raider. I have also had people comment that the signal from the 6 element curtain array holds fairly stable. I've heard that about my Lazy H antennas as well. Since I only heard Southern California and Hawaii today I could not tell how the mid-west and northwest U.S. was coming in to the repositioned 6 element curtain array.
Night Ranger
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Sandbagger
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Post by Sandbagger on Mar 19, 2012 7:00:30 GMT -5
I repositioned the 6 element curtain array to about 17 to 21 degrees north of west. There was not much skip in today, but when southern California came in I was still getting favorable reports. I did an A/B test with 167 Ron in southern California and he said the horizontal dipole was putting S5 on him and the 6 element curtain array way putting S9 on him. I was using 200 watts output from the D&A Raider. I have also had people comment that the signal from the 6 element curtain array holds fairly stable. I've heard that about my Lazy H antennas as well. Since I only heard Southern California and Hawaii today I could not tell how the mid-west and northwest U.S. was coming in to the repositioned 6 element curtain array. Night Ranger I remember well how stable the Lazy-H was last summer. When you were in there, it was steady, with little waver, as long as the conditions were good. It certainly made carrying on longer QSO's a heck of a lot easier. |
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Post by cbrown on Mar 19, 2012 8:12:47 GMT -5
Later in the day I got a second signal report from a station "1212" in Hawaii. He heard me called on 38 LSB, and then we dropped to 37 LSB for an A/B signal test. The station in Hawaii said on his Yaesu FT-757 I was putting an S3 to S4 on my dipole, and on the six element curtain array I was putting between an S8 and an S9. That is an impressive increase! Almost 30 db! |
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Post by Night Ranger on Mar 20, 2012 18:11:24 GMT -5
Later in the day I got a second signal report from a station "1212" in Hawaii. He heard me called on 38 LSB, and then we dropped to 37 LSB for an A/B signal test. The station in Hawaii said on his Yaesu FT-757 I was putting an S3 to S4 on my dipole, and on the six element curtain array I was putting between an S8 and an S9. That is an impressive increase! Almost 30 db! I decided to hook my Kenwood TS-850sat and my Drake L-4B with two 3-500zg tubes up to the 6 element curtain array, and see what the signal reports were like. A station in Hawaii broke me, and he said he was running an Icom 751a on a 3 element Maco. When I asked him what my signal was in Hawaii he said I was 20db over S9! Can you see me grinning? Oh yea, and that was on the sideband super bowl over top of the afternoon DX pile-up. he he he Night Ranger |
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Post by cbrown on Mar 21, 2012 8:20:58 GMT -5
Very nice! Love those 3-500 tubes too.
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wr54
Mudduck
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Post by wr54 on Mar 21, 2012 19:14:32 GMT -5
;D ;D You were 10-15 db up here in Colorado,,the curtain sounded great !! Great job !!! 73 WR54
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Post by Night Ranger on Mar 21, 2012 19:37:47 GMT -5
;D ;D You were 10-15 db up here in Colorado,,the curtain sounded great !! Great job !!! 73 WR54 You sounded great in South Carolina. I had you at 15 to 20db over S9. The conditions tonight were a little odd. I had some weak hispanic skip still coming in, but California pretty much disappeared. Colorado was one of the last states still coming in. Night Ranger/South Carolina 116 |
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Sandbagger
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Post by Sandbagger on Mar 22, 2012 6:08:36 GMT -5
;D ;D You were 10-15 db up here in Colorado,,the curtain sounded great !! Great job !!! 73 WR54 You sounded great in South Carolina. I had you at 15 to 20db over S9. The conditions tonight were a little odd. I had some weak hispanic skip still coming in, but California pretty much disappeared. Colorado was one of the last states still coming in. Night Ranger/South Carolina 116 Skip was running during the first half of CRR, but I didn't hear anything from your neck of the woods. |
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Post by Night Ranger on Mar 22, 2012 8:33:54 GMT -5
You sounded great in South Carolina. I had you at 15 to 20db over S9. The conditions tonight were a little odd. I had some weak hispanic skip still coming in, but California pretty much disappeared. Colorado was one of the last states still coming in. Night Ranger/South Carolina 116 Skip was running during the first half of CRR, but I didn't hear anything from your neck of the woods. I have not heard anything out of Pennsylvania since the minor winter sporadic E skip season closed back in January. I may be running in to a disadvantage of the 6 element curtain array. If you go back to the initial EZNEC graph plot it shows a low take off angle and a compressed lobe in the vertical plane. See below; Look at the "2D Plot" graph below; www.shadowstorm.com/images/6ElementCurtainArray.jpgIn the evening there are times when Hawaii is actually coming in stronger than California on the six element curtain array, and some of my strongest signal reports are coming from Hawaii. Although it is too early to be certain I am beginning to wonder if the strongest parts of my output is over shooting California and hitting Hawaii due to the low take off angle and compressed vertical lobe. When the skip was waning or just coming up I have had reports that I was the only one coming in to California from the East Coast U.S. which may be indicative of the low take off angle. I've noticed when the skip is first coming in or just fading out the 6 element curtain array will pull in S5 and S6 signals from the west coast while the dipole can't even pull the signals out of the noise. Once the skip is wide open the results are less pronounced although the six element curtain array is still consistently pulling in the stronger signals by several S units and it consistently gets the stronger signal reports on transmit. Night Ranger |
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Sandbagger
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Post by Sandbagger on Mar 22, 2012 12:18:44 GMT -5
Skip was running during the first half of CRR, but I didn't hear anything from your neck of the woods. I have not heard anything out of Pennsylvania since the minor winter sporadic E skip season closed back in January. I may be running in to a disadvantage of the 6 element curtain array. If you go back to the initial EZNEC graph plot it shows a low take off angle and a compressed lobe in the vertical plane. See below; Look at the "2D Plot" graph below; www.shadowstorm.com/images/6ElementCurtainArray.jpgIn the evening there are times when Hawaii is actually coming in stronger than California on the six element curtain array, and some of my strongest signal reports are coming from Hawaii. Although it is too early to be certain I am beginning to wonder if the strongest parts of my output is over shooting California and hitting Hawaii due to the low take off angle and compressed vertical lobe. When the skip was waning or just coming up I have had reports that I was the only one coming in to California from the East Coast U.S. which may be indicative of the low take off angle. I've noticed when the skip is first coming in or just fading out the 6 element curtain array will pull in S5 and S6 signals from the west coast while the dipole can't even pull the signals out of the noise. Once the skip is wide open the results are less pronounced although the six element curtain array is still consistently pulling in the stronger signals by several S units and it consistently gets the stronger signal reports on transmit. Night Ranger That's why a great deal of hams have several different antenna configurations for their favorite DX bands. Sometimes a low angle of radiation is desirable, other times a slightly higher AOR is preferable depending on where you want to talk and the type of conditions are in control at that moment. Polarity can also make a difference. I have a friend who has his HF beam on a crank-up tower, which he has motorized. Just changing the antenna height above the ground changes AOR and affects which areas you hear strongest. To many people, understanding propagation is the "fun" part of radio. |
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Post by Night Ranger on Mar 23, 2012 16:24:38 GMT -5
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Post by Night Ranger on Mar 23, 2012 20:24:20 GMT -5
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Post by Night Ranger on May 27, 2012 8:46:38 GMT -5
My 6 element curtain array and Sporadic E skip to Arkansas from South Carolina...
I have been a little concerned that my 6 element curtain array might have too low a take off angle and too much of a vertically compressed lobe for close in skip during sporadic E skip. The current array is suppose to have maximum gain at 11 degrees above the horizon. I have been getting multiple 20 over S9 signal reports out of Hawaii from my location in South Carolina.
Now that the summer sporadic E skip season has started I decided to try out the 6 element array for closer in contacts. I caught up with one regular I use to talk to last summer located in Arkansas. He said he was using a Kenwood TS-940s on an inverted V wire antenna. Then he said I was hitting him at 60 over S9, and that I was giving him the strongest signal he had seen yet on his wire antenna. Time will tell if my monster signal report was a condition fluke, but it gave me a big smile none the less. I had up to 35 over S9 on him.
: )
Night Ranger
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Post by Night Ranger on Jun 19, 2012 11:15:46 GMT -5
I took my 6 element curtain array for a spin on the channel 6 Super Bowl.
Normally I don't spend time on channel 6. It's just not my kind of channel. Plus there are so many ridiculously large power amplifiers down there I figured I would have no chance of making a contact. Still I was curious to see if my 6 element curtain array and a 500 watt dead key could bust the pileup down there, so I tuned everything up on channel 5 and then made a few calls on channel 6. To my surprise a station in Texas called "Black Diamond" came back to me after about my third or fourth call. I don't think my signal was ruling the channel like Clarence Carter use to do, but the fact that I managed to get above the pileup for at least a few seconds made me proud of my little home made antenna.
; )
Night Ranger
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Post by cbrown on Jun 20, 2012 8:47:26 GMT -5
If you made it through that mess, I'm impressed with the antenna!
I hope you at least distorted your audio enough! ;D
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**GRUMPY**
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Classic Radio Operator Olde Timer 8220 [/color][/center]
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Post by **GRUMPY** on Jun 20, 2012 8:52:26 GMT -5
If you made it through that mess, I'm impressed with the antenna! I hope you at least distorted your audio enough! ;D  |
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Post by cbrown on Jun 21, 2012 8:31:23 GMT -5
I tend to stay away from that channel, it's just a nightmare. Besides, I refuse to make my radio sound that bad.  |
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Post by Night Ranger on Nov 10, 2012 15:24:05 GMT -5
I received a 30 over S9 signal report out of New Mexico this morning on channel 38 LSB using my six element curtain array and 200 watts output. I had the HD camera recording the conversation. www.youtube.com/watch?v=n_CzJPacS_0: ) Night Ranger |
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Post by homerbb on Nov 11, 2012 9:10:32 GMT -5
Sounds like you made a winner.
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