280 Foot Sky Loop Fed With 80 Feet of 600 Ohm Open Wire Feed Line
Sky Loop 80 Meters One Element Reflector
Manuel G. Caldera (KC6ZSY) on August 30, 2007View comments about this article!
Sky Loop 80 Meter 1 Element Reflector Beam Antenna
By Manuel Caldera, KC6ZSY
Dot. Dot. Dot. Dash. Dash. Dash. Dot. Dot. Dot.
July 30, 2007, M.C.
When I joined Civil-Air-Patrol, in 1970, as a cadet, I was exposed to the California Wing Amateur Radio Communication Center for the first time. I was very impressed to see young men and woman manning the radio equipment with such professionalism; I wanted to become cadet. And I did. And so the journey started. Along the way I obtained my HAM license, built radios, put up antennas, made antenna kits, and boy, did I have a lot of fun. Now days, when I hear someone having an antenna party, I am there. Building antennas is my cup-of-tea. You have my full attention, so they say.
The summer of 2006, we decided (my two sons, and I) to put up a sky loop 80 meter antenna that was used at Field-Day several years ago. Hanging on a nail in the garage since 2001 that was just attracting dust. My two sons' have taken an interest in amateur radio, so this was a good time to exposed them to this incredible, and exciting hobby. We planned the entire project, purchasing a new drill, drill bit for cement drilling, clamps, rope, pulley, insulators (plastic), 450 ladder-line, and other related material to sustain six twenty-five feet poles around our home.
A week later, the entire project was completed, and we were on the air CQing five hundred miles away from our home. The boys were impressed, but I was not. The sky loop antenna, which horizontal is to suppose to hear better, cut down on white noise, better match, and transmit better than verticals antenna's, but I was not getting the performance from articles I have read over the last several years.
A phone call was made to my friend Richard Schick (HAM Buddy since 1993; KE6BKE), who was also in the process of enhancing his sky loop antenna. After an hour of exchanged antenna theory's we came up with an outstanding plan-of-attack. To me it sounded like were going to war. "That was a good laugh… Those action items were:
1. Increasing the feed line (ladder-line) from 35 feet to 47 feet.
2. Running 18ga. copper wire around the inside of the loop wire ten feet off the ground to act as a reflector/beam. Six insulators and plastic zip ties were used to hold the insulators on the pole, plus one wire tension adjustor.
1. I solder six more feet of ladder-line to the existing ladder-line, which was now forty-one feet long. I turned on the radio on the AM band, and notice I was able to tune the wire antenna better, and faster than before. I was feeling somewhat excited at this point, but I continued. I looked at my power supply, which has an AMP, and Volts meters, and notice that I went from 7 amps to 10 amps on the AM band. That indicated I was putting "out" more power to the wire! I switched to SSB on 20 meters, and called out CQ several times watching the amp meter at the same time. I notice I went to 14 amps. Plus, I had someone answer the call. I obtained a very good signal report and other related information. I notice the HAM QTH was about thousand miles away. Not bad, but I could do much better.
I added six more feet to the ladder-line, which was now forty-seven feet long. I went through the same procedure checking and amps and volt meter as before, but this time my amps dropped to 9.5 (on the AM band), and the tuner took more adjustment than before. So, I cut off three-feet of ladder-line, which was now forty-four feet long, and went through the same process, only this time, I went to 11 amps when tuning on the AM band. I repeated the process on the wire tuner, and called out on 20 meters, I noticed that I went up to 18 amps when calling out CQ. Another HAM answered the called, and I logged him in the book. I notice his QTH was also about fifteen-hundred miles away. Still not satisfy. From here, I decided to implement step 2.
2. The following weekend, my younger son, and I were up before sun rise that morning. We started on one end the sky-loop pole ten feet up, and placed an insulator against the pole with a zip tie. The 18ga wire was fed through the other hold, and continues to the other poled one at a time. One-hour, and thirty minutes later, we were done. By this time, the sun was coming just over the trees, and perfect to jump on 20 meters for a test. I went though the same procedures as before, and notice the wire tuner match quickly. I called out CQ, and a station from Tampa, FL some 2,700 miles away returned my call with a report of 5.9. I said to myself, now were talking. The HAM operator in Florida wanted a full report on my HAM setup, and I replied that I was using a FT-900 Yaesu with a sky-loop antenna with 100 watts with my antenna twenty-five feet off the ground, but with a one-element beam reflector on the bottom. Within minutes of our conversation, I had a pile-up on 20 meters asking about my new configuration. Now, I was very impressed...
Member Comments:
This article has expired. No more comments may be added.| Sky Loop 80 Meters One Element Reflector | |
| by ZL2OM on August 30, 2007 | Mail this to a friend! |
| Very interesting. I run a 80 mx horizontal loop here in ZL. could you post more info about the reflecting element | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by NI0C on August 30, 2007 | Mail this to a friend! |
| The headline for this article is misleading, as the anecdotes concerning performance of the antenna describe operations on the 20m band. 73, | |
| Sky Loop 80 Meters One Element Reflector | |
| by K4QO on August 30, 2007 | Mail this to a friend! |
| Maybe I mis-read your post... Do you have a special license that lets you transmit on the AM band? What were you thinking? Please stop testing your antennas on that band. That was irresponsible and illegal. Don't get me started on the "DOT DASH" sub-heading. Perhaps the two items are related. | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by OZ8AGB on August 30, 2007 | Mail this to a friend! |
| I put up at horizontal loop 3 weeks ago. It is approx. 110m long and is fed with 40 feet 450 ladder line. I guess I have a reflector as the loop is above a wire fence in my garden. It performs beautifully on 20m. I have not had much time to really test it yet, but I have made new contacts in VK2, HS1, PY1 during the few hours I tried it. 73 de | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by N4JTE on August 30, 2007 | Mail this to a friend! |
| I'm confused. Element lengths would be helpful. As I understand it, you spent a lot of time and work to match a cloud burner. Bob | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by K4SFC on August 30, 2007 | Mail this to a friend! |
| Hams that use ladder line are just determined to make things more difficult. SRI but that goes for my friends too. If you will build a "LOOP SKYWIRE" just as it is described in Nov '85 QST page 20. You will have an EASY to build, EFFICIENT antenna. etc. I can fill up this page with superlatives but you get the drift. And if you put a waterproof auto-tuner up on a pole outdoors and ONLY tune the ANTENNA wire all the power goes there as it is intended. I work 6-160M with mine. Almost zero Maintenance and it is SIMPLE to build. You don't need balums either. Thirty years as a ham means I have had lots of antennas. Homebrew and commercial. This is the most fun antenna I have ever had. And it works great. I sold my HF amplifier in 1984 and never purchased another. Dont' need it! Only one sticking point, you must find a really good ground. | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by N9XY on August 30, 2007 | Mail this to a friend! |
| To: K4QO I suspect that when Manny said "AM Band", he meant that he was tuning in AM mode on the AM segment of 80m band. 73 | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by W9OY on August 30, 2007 | Mail this to a friend! |
| WOW I think this antenna could probably work Pluto!!! Where can I buy a really good ground? MFJ? 73 W9OY | |
| Sky Loop 80 Meters One Element Reflector | |
| by WW5AA on August 30, 2007 | Mail this to a friend! |
| I like my 160-6 skyloop also, however as is the usual case I could only get it up to 25'. It is usually down several DB from my TX doublet at 70'. For receive however it is very close, but still down from my RX antenna. I would love to compare it at 70'. 73, de Lindy | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by KF4HR on August 30, 2007 | Mail this to a friend! |
| First, thank you for posting an interesting article. I was trying to keep up with your article, as it pertained to dimenions. Adding or subtracting from the ladder line optimized your feedpoint impedence and RF engery transfer; which is definitely a good thing. I'm not an antenna expert, but I wonder if the reflector loop distance is anywhere near optimal? I'm picturing a typical yagi with elements spaced somewhere around 0.15 WL (if I did my math right 80 meters is ~39'?). Anyway, if I read your article correctly it sounds like the two elements are spacing around 15' apart. Is that correct? In any case, congraduations on making a standard loop antenna work even better. I had a horizontal 80 meter loop up a couple of years ago but a lightning strike did-it-in and I haven't gotten around to re-installing it yet. I found my horizonal loop (which was about 25' off the ground) to be much quieter than my windom antenna, although I don't think the loop had a low take-over angle, compared to my windom. Antenna experimenting... definitely fun stuff! :^)) KF4HR | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by K6TPL on August 30, 2007 | Mail this to a friend! |
| I'm not sure how you would even get a radio to tune on the AM Band! However in my close to 50 years of operating and more antennas than I can remember. I've never had a antenna perform better than the simple Sky Loop! Mainly use loops for 75 and 160. Use a Beam on the 17 and 20 meter Band. As to the sub heading Want me to call 911? | |
| Sky Loop 80 Meters One Element Reflector | |
| by NE4EB on August 30, 2007 | Mail this to a friend! |
| The heading is not misleading for those of us who use 80-Meter horizontal loops. This antenna is the best kept secret in amateur radio. As the author found out, adjusting feedline length to find the sweet spot is very important, and it's not hard. I have a 300' wire loop up 20 ft. supported by trees on all four corners of my residential lot. The 450 Ohm line goes straight into the shack to a Palstar ATV1500CV. Sine March 07 when I started keeping track, I have just under 5000 QSO's in the log of which are 115 unique DXCC entities and of those 70 are confirmed. All this from an 80-meter loop at 20 ft. with 100 watts. It tunes from 80 to 6 meters with ease and is a fantastic performer. The thought of adding a reflector or any other such baggage to this classic antenna has never crossed my mind. Did I mention that it is a lot more quiet than a doublet? Those who call a low multi-band horiz. loop a cloudburner or yack on and on about how ladder lines "radiates" have no clue as what they are even talking about. | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by K9FV on August 30, 2007 | Mail this to a friend! |
| Did I miss where you were checking SWR? If so, how did changing the ladder line a few feet affect the SWR??? 73 de Ken H. | |
| Sky Loop 80 Meters One Element Reflector | |
| by W4VR on August 30, 2007 | Mail this to a friend! |
| what in the heck are you attempting to describe? This is a poorly written article if I've ever seen one. | |
| Just say no to antenna myths | |
| by K9ZF on August 30, 2007 | Mail this to a friend! |
| Learn real antenna facts at: http://www.cebik.com/ 73 | |
| Sky Loop 80 Meters One Element Reflector | |
| by W2IHY on August 30, 2007 | Mail this to a friend! |
| For the past 12 years I have run an 80 meter horizontal full wave Delta loop with a reflector. I consider it a very good performing antenna on80meters. The equation I used was straight forward. The driven element length (in feet) is 1005/freq. MHz The reflector length is 5 percent longer than the driven element or 1.05 x 1005/freq MHz . The spacing of the elements i s .12 x 1005/freq MHz . My antenna was tuned to be resonant at 3.800 Mhz. The driven element is 265 feet long, The reflector , which is a closed loop, is 278 feet long and the spacing between loops is 32 feet. I feed the loop with 50 ohm coax. I do use a tuner to tune the entire 80meter band however the antenna, without a tuner has an SWR below 1.2 : 1 at resonance. I am away on vacation as I write this or I would better quote the SWR vs frequency characteristics of the antenna. My loop is configured as a Delta loop. It is an equilateral triangle. The driven element is at a height of 60 feet. I have compared the characteristics of the antenna with both an 80 meter dipole and a 160 meter Carolina Windom which is a full wave on 80. On contacts under about 1200 miles the loop is almost always better than or at worse equal to the other antennas. I have since taken the dipole down. More specifically in recent times the loop is up to 10 dB stronger than the Carolina windom and dipole as observed by the parties I was talking to. I have used a tuner to use the 80 meter loop on other bands. When I compared the loop with my Mosely PRO 67 C3 I have found that with coax the loop performed up to 20 dB worse than the PRO 67 on 40 meters. On the other bands the loop performed within 0 to 2 s units of the PRO 67. I considered this not bad. My 80 meter loop is a very very poor performer on 160 meters that is why I put up the 160 meter Carolina Windom. Julius(W2HY) | |
| Sky Loop 80 Meters One Element Reflector | |
| by K1CJS on August 30, 2007 | Mail this to a friend! |
| This IS an interesting article. The authors terminology is a little off, but those who do work on antennas and who have some experiemce know exactly what he is talking about by his use of "AM band"--using AM on the 80 meter band. I appreciate the article because I'm planning an antenna something like this. One question for you, Manny--I'd like to ask exactly where and at what relative angle the 'reflector' loop was added. I did see the 'ten feet off the ground' comment. Also, ladder line is something that hams with the experience or knowledge to use it can use with sometimes better results than co-ax. Just because you don't have that knowledge, don't poo-poo its uses. Co-ax didn't always exist, you know. As an aside, I'm still surprised that some posters here come here just to find fault with technical or construction articles that seek to impart a little knowledge and common sense to others. Witty remarks and arguments about off the wall subjects are one thing, calling somebody down just because you don't like their ideas on a project they undertook is plain rude. Instead of being abrasive, why not suggest an idea or a better way to proceed if you know of something that may be done differently. I guarantee you'll have a better reception than if you call someone down or ridicule their ideas. Think about it. | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by N1LO on August 30, 2007 | Mail this to a friend! |
| 80m sky loops are my favorite all-around antenna. Parallel feedline is definitely the way to go for multiband operation. Adjusting the length of a parallel feed line is a very common way to help present your tuner with more easily matched impedances. I never thought about looking at the current consumption to judge transmitting efficiency. Did your observations track with RF power out? I would guess that the reflector would be of most benefit only on 80m, and might work better if you put it at ground level. This should give you great performance for 80m ragchew and nets within a 1 state radius. Show the boys PSK and they'll eat it up! --...MARK_N1LO...-- | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by WR8D on August 30, 2007 | Mail this to a friend! |
| Manuel, take your antenna one knotch higher by making your own ladder line. Spaced at 6inches there's no skin effect when it rains or snows the swr just sits where you tune it. I've worked Japan barefoot on 20 here at the bottom of this cycle with mine. 275 feet of wire at 40 feet off the ground in a triangle with 125 feet of homemade feeder spaced at 6 inches into a centaur 4.1 balun. 80/10 meters perfection. I ran my reflector right on the ground under the over head loop. Nothing scientific about it i just made it a little bigger on the ground than the shape of it was over head. You can do the same with a simple dipole too and the reflector will really make a differance. Pay no mind at all to those fussing about ladder line in an antenna system. I've tested individual antennas cut for individual bands feeding them with coax against this loop and there is no comparison between them. A loop either fed with the 75 ohm matching stub cut for one band or feeding a loop with 450 ohm and tuning it with a tuner for all bands will "smoke" them all. Nuff said. Enjoy that sky hook and i'm sure just like me you'll always have one of those in the air regardless of what other antennas you have up. 73 Have a great labor day weekend. John WR8D | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by N7BUI on August 30, 2007 | Mail this to a friend! |
| "Maybe I mis-read your post... Do you have a special license that lets you transmit on the AM band? What were you thinking? Please stop testing your antennas on that band. That was irresponsible and illegal. Don't get me started on the "DOT DASH" sub-heading. Perhaps the two items are related." "what in the heck are you attempting to describe? This is a poorly written article if I've ever seen one." "Learn real antenna facts at: http://www.cebik.com/" The reason why writing an article for eham is a waste of time. It was an interesting read Manuel. I wonder if you have put up something similar to what Art Bell has at his Pahrump property. His has a bottom element that is several feet below the main loop. | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by KC8VWM on August 30, 2007 | Mail this to a friend! |
| Of course some of us are smart enough to realize this is not intended as a technical "Cebik" article but rather it's one which documents some interesting experimental observations using a skyloop antenna design. It also gave me some food for thought in the area of using the draw on your power supply as an antenna calibration tool. Thanks for the time and effort you put into writing this article. I enjoyed it. Keep experimenting! 73 de Charles - KC8VWM | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by KC6ZSY on August 30, 2007 | Mail this to a friend! |
| Good afternoon, and thank you for replying... My antenna is 25 feet off the ground. I placed the wire about 10 feet off the ground leaving 15 feet to the top wire. What I plan to do next is, clip a wire from the wire that is 10 feet off the ground to the ground rod. I will retake my measurements again... I have 44 feet of 450 going to the top wire, and with 83% of 100 watts going out. Go to: www.ac6la.com, and download the TLDetails - Transmission Line Program with Animated Charts. This help me a lot to move forward. 73's Manny Caldera | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by KC6ZSY on August 30, 2007 | Mail this to a friend! |
| Good afternoon, and thank you for replying... My antenna is 25 feet off the ground. I placed the wire about 10 feet off the ground leaving 15 feet to the top wire. What I plan to do next is, clip a wire from the wire that is 10 feet off the ground to the ground rod. I will retake my measurements again... I have 44 feet of 450 going to the top wire, and with 83% of 100 watts going out. Go to: www.ac6la.com, and download the TLDetails - Transmission Line Program with Animated Charts. This help me a lot to move forward. 73's Manny Caldera | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by KC6ZSY on August 30, 2007 | Mail this to a friend! |
| 272 feet of wire: Good afternoon, and thank you for replying... My antenna is 25 feet off the ground. I placed the wire about 10 feet off the ground leaving 15 feet to the top wire. What I plan to do next is, clip a wire from the wire that is 10 feet off the ground to the ground rod. I will retake my measurements again... I have 44 feet of 450 going to the top wire, and with 83% of 100 watts going out. Go to: www.ac6la.com, and download the TLDetails - Transmission Line Program with Animated Charts. This help me a lot to move forward. 73's Manny Caldera | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by KC6ZSY on August 30, 2007 | Mail this to a friend! |
| Yes... Thank you... I was tuning on the 80 meter side of the AM feg. But I will be tuning on 80 meter LSB side. | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by KC6ZSY on August 30, 2007 | Mail this to a friend! |
| Not MFJ, Home Depot. I have 4 ground rods for each pole. I have a clip going to the wire that is ten feet off the ground. Wow talk about getting out... | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by KC6ZSY on August 30, 2007 | Mail this to a friend! |
| The SWR dropped to 1.1, from 80 - 10 meters | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by KC6ZSY on August 30, 2007 | Mail this to a friend! |
| Thank you for your kind words from one HAM to another. | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by WR8D on August 30, 2007 | Mail this to a friend! |
| Larry, it took me a week between working and all that to build my feed line. Sometimes and certainly in this case of how my loop performs it was worth all the aggravation.... I got the idea on homebrewing my feedline from some retired air force pals of mine that have been stationed all over the world. It's simple to do but time consuming but the payoff is fantastic. Verses feeding with coax and that 75 ohm matching stub the 450 as we say puts the fire in the antenna wire. Using the 75 ohm matching stub limits you to just that one band you've cut the loop for, wire feeders really turn it loose on all bands. 73 John WR8D | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by N9XCR on August 30, 2007 | Mail this to a friend! |
| "As I understand it, you spent a lot of time and work to match a cloud burner." That's what a lot of people say about loops that aren't up at least one-half wavelength(?), but it's all based on theory. Loops, though, tend to yield results that are pleasantly surprising. I just installed a full-wave 40M loop a couple weeks ago. The loop is about 27-30' high, and I was only able to utilize three supports. The 4th ended up being a little too dangerous to get at with the ladder I had. I've only tuned it up on 40 and above so far; I haven't attempted any QSOs yet. I hope my results are similar to the accounts I've read of others who have installed their loops at around the same height. 73, | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by N9FE on August 30, 2007 | Mail this to a friend! |
| Good job manny, Keep it up, Hope to work you soon, Also pee pee on the naysayers they don't have anything else to do with thereselves.. | |
| Sky Loop 80 Meters One Element Reflector | |
| by W5PVR on August 30, 2007 | Mail this to a friend! |
| A horizontal loop one wave length long on its fundimental frequency is classified as a "Nevis Antenna". Nevis means Near Vertical Incidence, but you knew that. Note the first word "Near" Eznec 5+ shows that there are many angles, between the vertical, and the 3db point. where radation takes place at an angle much lower than the Vertical. On it's harmonics the loop really performs. Power is radiated at lower angles as the frequency increases therefore directional gain increases until at 10 Meters it has almost as much Gain as a three element beam over 1/2 wave high. A reflector wire below the loop will give some gain but on one band only. A loop on its harmonics radiates in some horizontal directions,the "Gain" comes from the absence of radiation in the other directions, or "pattern nulls". Bob,w5pvr | |
| Sky Loop 80 Meters One Element Reflector | |
| by WA6BFH on August 30, 2007 | Mail this to a friend! |
| I find that on 80 Meters, and other such low frequency longer wavelengths, I have to talk very slooooowly! Also, on 80 Meters, there are way too many Adam Henry's! 73, and .... .. .... .. ! de John | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by KC8VWM on August 30, 2007 | Mail this to a friend! |
| Antenna height above the ground and operating frequency are the main considerations in determining if this is considered as a NVIS antenna or not. It's not likely to perform as an NVIS antenna on the 80m band. 73 de Charles - KC8VWM | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by AB7E on August 30, 2007 | Mail this to a friend! |
| N1LO: "I never thought about looking at the current consumption to judge transmitting efficiency." That's probably because, as you suspected, the two aren't directly related. Tuning for more power supply current is a bad way to adjust an antenna, and a good way to destroy expensive equipment. By the way, I have nothing against horizontal loops. There are some pretty effective designs out there for short haul work ... even for DX on the higher bands in some cases. I think one of them comes included with EZNEC. Dave AB7E | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by ICR71A on August 30, 2007 | Mail this to a friend! |
| What the hell? Someone posts a vague article and the armchair technicians crawl out of the woodwork... As to antennas, there is no difference between a radiator that works SSB or AM. It is obvious that by "AM Band" this would-be technologist means A3E mode on whatever allocation he was using. If this was an expository in my classroom, it would garner a D... | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by KC6ZSY on August 30, 2007 | Mail this to a friend! |
| ICR7IA, thank you for your comments, but I did not write my article to receive a grade, but to share. This is Amateur Radio; a hobby to have fun, and to continue to learn. 73's Manny Caldera... | |
| Sky Loop 80 Meters One Element Reflector | |
| by KC6ZSY on August 30, 2007 | Mail this to a friend! |
| "KE6BKE-RICHARD SCHICK" The response to Manuel's article has been overwhelmingly an affirmation of the merits of the sky-loop antenna. It still frustrates me that the merits of balanced line feeds has not found the following it should for low feed line loss and the solve for some RFI problems in the shack. To take the matter even further - tuning the feed line to match transmitter output into the balun and thereby getting all the power out of the radio. 1. Using a smaller gauge wire An important note, when I don't use the ATU I pull an additional 1.5 amps and the receive improves (same SWR reading as with ATU.) Any constructive thoughts are appreciated | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by N7YA on August 30, 2007 | Mail this to a friend! |
| Manny, You have a great attitude! I knew as soon as you posted this article that you would be attacked and you handled it like a man...and i appreciate your devotion to experimenting and checking your work. Also, i find it funny that this thread is only a day or two old and already i have seen the words "poopoo"...AND..."peepee". hehehe...thats just funny to me. we all need to laugh a little bit more and try to enjoy ourselves. keep up the good work, sounds like a great antenna. 73...Adam, N7YA | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by N7YA on August 30, 2007 | Mail this to a friend! |
| Manny, by the way, my son is going to his first CAP meeting this tuesday, he plans on learning to fly and he is going to be taking their ham radio course...between them and myself, we will turn out a good new ham. Thanks again for sharing your work....N7YA | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by KC6ZSY on August 30, 2007 | Mail this to a friend! |
| N7YA, Your son will learn so much in CAP, obtaining his HAM licenses will go a-long way too! 73's Manny Caldera... Keep moving forward... | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by N9XCR on August 30, 2007 | Mail this to a friend! |
| BTW, I meant to say earlier that I enjoyed reading your article, Manny. Sure, some other technical details would have helped the discussion as others mentioned but it was still a good article. It's exactly the type of thing that should spark intelligent conversation amongst us. Chris | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by KE3WD on August 30, 2007 | Mail this to a friend! |
| This ham thinks that reading about Manny working with his sons on an antenna project is an excellent thing. Manny is to be commended on that front alone. Modern solid state rig with SWR power foldback to protect the PA, you could indeed get good information out of the VA meters on the power supply. Just don't try that one with the old tube driven boat anchor. "Have fun" KE3WD said that. | |
| Sky Loop 80 Meters One Element Reflector | |
| by KI6JUU on August 31, 2007 | Mail this to a friend! |
| Thanks for an interesting article. I also enjoy diddling around with different antennas also, just to see how close they match the performance that others have experienced. | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by W6TH on August 31, 2007 | Mail this to a friend! |
| . This ham says gain in a different way. A loop on its harmonics radiates in some horizontal directions,the "Gain" comes from the absence of radiation in the other directions, or "pattern nulls". Gain of an antenna is measured at the 3 dB points of the aperture of the beam lobe. What is there to gain by having the open wire line spaced 6 inches over 4 inches. High powered transmitters went for the 6 and 8 inch spacing to prevent arcing over on the line ( VSWR ), lower power were satisfied with 3 and 4 inches. What difference does the line impedance make, if any? I enjoyed the post information and especially the amount of time and effort put forth. 73, W6TH. .: | |
| Sky Loop 80 Meters One Element Reflector | |
| by KE4ZHN on August 31, 2007 | Mail this to a friend! |
| The full wave loop is a great antenna. Ive heard many on the air and they all seemed to perform well. Unfortunately I cant put up an 80 mtr. loop at my location but Id love to try one. Im no antenna engineer, but the idea of putting a reflector wire under the loop should work fine for operation on 75/80, but if the loop is used on other bands the reflector is useless. Perhaps it would make more sense to bury a ground screen under the loop to reduce ground losses on all bands used. Just a thought. | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by W6TH on August 31, 2007 | Mail this to a friend! |
| . For the 75/80 meter band the height of the loop will have more gain ( maximum gain ) when the wire reflector is at a quarter wave below the driven element. As you increase the frequency, the reflector starts to diminish on gain and at certain points above the quarter wave, the antenna loop will start to form the elevation angle of radiation. At greater heights , say around a full wave, the main lobes splits and the forward power is split in proportion which one will be at a higher angle and one will be at a lower angle. This is due to the antenna loop and reflector being are out of phase. I could go deeper in explanation, but am afraid I will be over most heads. W6TH .: | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by N9FE on September 1, 2007 | Mail this to a friend! |
| That's ok vito don't go any deeper your attitude is deep enough. There are many operators with 50 or 60 years plus that i talk to everyday, but they never brag or talk down to anybody, Those are the real teachers of this hobby, And those are the ones i listen to.. | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by W0IPL on September 1, 2007 | Mail this to a friend! |
| Well, at least one person was able to say NVIS. http://www.cebik.com/wire/cb.html | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by UC1AWX on September 1, 2007 | Mail this to a friend! |
| As K4SFC said, place for the tuner is up on the pole, even if it IS a random wire. What beyond my comprehension, is why tuner sits on the other end of feeder most of the times. Common wisdom suggest me it's wrong place for it. What I'm missing? | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by KB9WIS on September 1, 2007 | Mail this to a friend! |
| Actually, I think you could do much better than that, with a 1/4 vertical, mounted 10 or more feet off the ground.. A vertical when done properly, has superior low angle of radiation, translating to further dx/contacts. | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by AB7E on September 1, 2007 | Mail this to a friend! |
| W6TH: "At greater heights , say around a full wave, the main lobes splits and the forward power is split in proportion which one will be at a higher angle and one will be at a lower angle. This is due to the antenna loop and reflector being are out of phase." No ... that isn't true. A simple EZNEC model says the currents are essentially in phase and there is relatively little difference in gain whether the reflector wire is there or not, assuming an 80m loop at 75 feet with reflector wire at 15 feet, upper wire driven on 14 MHz (for one wavelength spacing). On 80m the reflector helps, but the additional gain is all upward. W6TH: "I could go deeper in explanation, but am afraid I will be over most heads." Possibly ... but you'd still be wrong. Dave AB7E | |
| Sky Loop 80 Meters One Element Reflector | |
| by WA3MEJ on September 1, 2007 | Mail this to a friend! |
| If you want more information about the design of this antenna see the loop antenna sections in L.B.'s articles. I am using one of these antennas and they work great ...BUT you should know that they are meant for NVIS (close in work) NOT DX they are cloud burners. Here is the link look through the design articles, even though he gives a lot of statistics with his articles he tells how to make them with enough info that you can make your own easily. http://www.cebik.com/radio.html Jim | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by WA3MEJ on September 1, 2007 | Mail this to a friend! |
| As I stated above look at http://www.cebik.com/radio.html HIs articles will shed a lot of light on the topic, patterns and all. With regard to tuners... this is a balanced antenna and you should NOT be using a balun in your antenna tuner if you want it to stay ballanced. Instead use a ballanced tuner with two coils and one capacitor and feed the antenna with 450 ohm ladder line. This way it WILL stay balanced at all frequencies. Yes I know the tuner is better if placed at the antenna but most of us dont have remote tuners and I have a habit of using my antenna on 3.3 and 4.9MHz a lot and I use it at the full legal limit. All I can tell you that it works so well that after reading L.B.'s articles I am putting up a 3wavelength loop on my property cut for 160m | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by W6TH on September 2, 2007 | Mail this to a friend! |
| . AB7E What I meant was if the loop was raised in height at the full wavelength and the reflector remained in its original position, whereby the loop was the full wavelength above the reflector. W6TH .: | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by AB7E on September 2, 2007 | Mail this to a friend! |
| To W6TH: That would require hoisting the upper loop to around 270 feet on 80m ... maybe that's what you meant by being "way over our heads". But yes, that would give one large high angle lobe and a much smaller one at a low angle. The currents in the two wires are still in phase, though. Basically, a horizontal loop is a cloud warmer on it's fundamental frequency and putting a second loop underneath it will make the clouds even warmer. A horizontal loop operated on its harmonics can offer very nice low angle gain on more than one band in selected directions (not omnidirectional), but a second loop close to the ground underneath it doesn't add much, if anything. Dave AB7E p.s. The antenna file N4PCloop that comes with EZNEC shows a nice dual feed version for anyone who wants to play with these things. | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by W6TH on September 2, 2007 | Mail this to a friend! |
| . AB7E Now, also consider that the reflector at any given height above ground with the same spacing of the loop to reflector, reflector to ground, there will be some rf getting into the earth, so consider the front to back ratio. This is an interesting antenna and can be very useful as an NVIS brain warmer as well. W6TH .: | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by WA8MEA on September 2, 2007 | Mail this to a friend! |
| W4VR, Ron writes: what in the heck are you attempting to describe? This is a poorly written article if I've ever seen one. (Ron's such an angry fella. He really needs a hobby....) ;-) 73, Bill - WA8MEA | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by W6TH on September 2, 2007 | Mail this to a friend! |
| . Hey Bill, MEA Watch what you say of my neighbor. .: | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by WA8MEA on September 2, 2007 | Mail this to a friend! |
| Hey Bill, MEA Watch what you say of my neighbor. How is it you guys get "rocket scientist" jobs when you can't even put a sentence together? I gess I are gonna start two pourly righting and might git me a gud job at NASA or sumthin lick that their.OK. ;-) 73, Bill - WA8MEA | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by W6TH on September 3, 2007 | Mail this to a friend! |
| . Bill MEA. If I put it in good English literacy,"literate" and proper adjectives and nouns and verbs, from your posting of your concept of English, I have to write as I am writing now for you to comprehend. W6TH | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by W6TH on September 3, 2007 | Mail this to a friend! |
| . Bill MEA How is it you guys get "rocket scientist" jobs when you can't even put a sentence together? Very simple Bill and as a rocket scientist, the talk is entirely different. The talk mostly consists of complex quantities, geometric functions, adjacent, brute force, harmonically related, relaxation and such as to conform. Most rocket scientists have to simplify the English language so most will be able to understand, to talk in the normal rocket scientist language, most would use repeatably the word, what, how, when and where. So you see, English has to fit in with the person one is corresponding to, with. W6TH .: | |
| Sky Loop 80 Meters One Element Reflector | |
| by KE7FD on September 3, 2007 | Mail this to a friend! |
| Manny and I have exchanged emails wherein he has been most open about his experience with the 80m loop. I have been using an 80m loop for the past few years and I must say it is the absolute best wire antenna I have ever used and in the last 30+ years I have used quite a few. His modification to the loop is what Amateur Radio is all about. It is almost like taking a two element quad and laying it down and getting [some] benefit from a reflector. Good idea Manny to you and your buddies. | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by WA8MEA on September 3, 2007 | Mail this to a friend! |
| So you see, English has to fit in with the person one is corresponding to, with. ------------------------------------------------------- I've corrected your homework Vito. --So you see English has to fit in with the person one is corresponding to/with.-- Now the question is, Vito: Can you correspond TO someone without corresponding WITH them? And/or can you correspond WITH someone while not corresponding TO them? And if a tree falls in the forest, will a bear crap in the woods? And if I travel faster than light, do I become darkness? And do you think God can make something travel so fast, that even He can't catch it???? ;-) 73, MEA Bill | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by K8GWW on September 4, 2007 | Mail this to a friend! |
| Thanks for the post, keeps the interest up. Bob, W5PVR wrote a good discription of how a NVIS antenna works and how the 80M loop works on the DX bands, so I will not repeat it. Bill Orr wrote some good articles on the "sky loop" also reporting its effectiveness on the DX bnds. As I read your article, you discribed putting he reflector inside of your loop, that would make it smaller and a director. Like Bob said, make it 5% longer and place it outside of the driven loop. I use an 80M dipole with a reflector 1.5 wave lengths below the driven element ((1/8the WL) or 33ft) I got this seperation from a US Army Signal Corp. manual and the ARRL books. www.cebik.com does give some closer spacings. Another positive aspect of your project not mentions by others is the involvement of your sons, that was great, I could just picture the group operation. We need to keep the spark of HAM radio going. 73, Jerry K8gww< | |
| Sky Loop 80 Meters One Element Reflector | |
| by A22EW on September 4, 2007 | Mail this to a friend! |
| I tried a similar mechanism in 1995 on 40m dipole by putting a 5% longer wire but it had to be about 30cm from the ground itself. Saw it mentioned in W6SAI book. It does improve performance for short skip. Ran tests for a year comparing it to single element delta loop in the same direction and height. Delta still outperformed 'reflected' dipole. | |
| Sky Loop 80 Meters One Element Reflector | |
| by VA1CQ on September 6, 2007 | Mail this to a friend! |
| I am currently using a 283-foot horizontal delta loop at 80 feet high with excellent results. Easy to install if you have tall trees. I use the antenna on all bands from 80 to 10 metres by using 600-ohm open wire feeder. The secret of this antenna is height. There is no magic; it is easy to model and modelled results with this configuration show significant gain at low angles of radiation on all bands except 80 metres. I'd be happy to correspond directly with anybody interested or who would like to see the low angle radiation plots. 73, | |
| RE: Sky Loop 80 Meters One Element Reflector | |
| by W4VR on September 7, 2007 | Mail this to a friend! |
| W4VR, Ron writes: what in the heck are you attempting to describe? This is a poorly written article if I've ever seen one. 73, Bill - WA8MEA | |
| Sky Loop 80 Meters One Element Reflector | |
| by K1DA on September 10, 2007 | Mail this to a friend! |
| The "80 meter side of the AM freq" --- does that thing work on 11 meters? | |
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