80m Ocf Dipole Length

The measurements below are for building a simple Dipole Antenna. Buckmaster 7-Band 300 Watt OCF Dipole Antenna (Click for larger image) Our 7-Band antennas cover 80, 40, 20, 17, 12, 10, and 6 meters , with no tuner required! Wire antennas are a great simple way to work 40M and 80M rather than a noisy vertical antenna that requires horizontal radials. 8B would provide an open circuit at 40 meters, a short circuit (λ/2) at 20 meters, and open again (3λ/4) at 15 meters. Off-center-Fed dipole Antennas is a curation of 13 resources about , OCF Dipole, The Six Meter OCF Sleeve Dipole Vertical, Center-Loaded Off-Center-Fed Dipole - 6 band, 80m OCF Dipole, Windom off center fed antenna 80-10 mt. The General phone portion of 80M is actually 75M (3. It might be interesting to try and create one of thesethere have been several commercial versions. Multi-Band Dipole I built a multiband dipole that will work and 10 meters for ham radio. The 10-80 meter ground plane is a huge antenna weighing 29 lbs. The OCF/ Windom is an excellent antenna that will perform quite well, both on transmit and also receive. The connector for the 50 Ω coaxial cable is an SO239 (PL) socket on the balun. An Off Center Fed Dipole for 80m Through 10m (and maybe 6m) Well, here I am…thinking about antennas for my base. The counterpoise is 16-ft long and the main element and counterpoise are suspended as a dipole. I started constructing one of these but soon came to realise that the balun was a compromise. A dipole at heights that most hams can manage like horizontal between maybe 20 and 35ft off the ground will give you lots more signal in the 100-500mi range on 40/60/80m and will also work good DX on most bands above 80m. The Short Dipole - There are several ways to reduce the length of a dipole and still use it as an effective antenna. On the bands above 20m it will work, but the performance may be down on what you could expect from a half-wave dipole cut for each particular band. I chose 58' for Mid 80 Meter Operation. If you want to use a dipole for a band of frequencies, you cut it to the center frequency on that band, and hope it has a low enough SWR at each end of the band. The SWR is generally below 1. MODEL 807-xx In addition to being erected in its full length, all 807-xx antennas can easily be shortened to half-size and erected as a 40m OCFD, still covering 7 bands. length of a dipole of ½ Honda of any band to choose, to be able to add it to the Original design increasing therefore I number of bands that can cover this antenna. The formula: For a dipole antenna cut to 3. Since sin(60deg) = sin(120deg), a. I have a fan dipole for 160,75,40 meters cut to length on each leg to have low S. Its best to do this with the antenna in the position that it will be used. Operating a center-fed dipole over the entire 80 m-band turns out to be particularly challenging. In the mean time I have the stuff to make a single dipole for use with 10-80M with primary focus on 10-20M which length would be best to use in conjunction with a FT-100 tuner?. Expect ham radio confidence with the DX Flagpole and it's Vertical Dipole cousins down to 80M! Q. I screwed a length of thin wall electrical metallic tubing (EMT) to the tree trunk and attached four heavy "screen door" springs to the EMT. The loaded dipole opens up the options for many armature radio users faced with space constraints. It consists of a simple dipole, either in a flat top or inverted V form, fed with a measured length of ladder line (300, 400, or 450 ohms) connected to a length of coax back to the ham shack and transceiver. I also used a 20 meter dipole in my attic successfully back then. It seems to work just as well or better as the 40m/30m fan dipole on those two bands. It's also ideal for those who want a high performance antenna with world class DX coverage. The idea of trying to get the virtual length to 88 feet was taken from some work done by the late W4RNL. Home Made Off Center Fed Dipole. Some get away with less but some require more length. 36 to get the length in feet. WATCH VIDEO at the best online prices at eBay!. Background. You only need to type in the numbers in the Cyan boxes. The basic formula for determining the length of a center fed, half-wave wire Dipole or Inverted Vee antenna is:. I do have wire antennas running along the privacy fence in the back yard and a new flagpole vertical coming in 2-3 weeks (mid March). So, an 80/160m trapped dipole will be an 80m dipole, with traps at the end of that, with additional wire to resonate it at 160m. An easy project I was able to tackle in one day. All I needed to fabricate is a replacement 50 ohm coax 1 wave in length and a 1/4 wave length of 75 ohm coax. Although the traditional OCF dipole had very broad band-segments, the VSWR-minima of either the 80 m or the 40 m-band could not be perfectly aligned to the respective band-centers. 5}{frequency(MHz)} for total length in metres. OCF Manual ver. The true OCF dipole must use. the height of a full-size half wave dipole, is very efficient, and has a 2:1 SWR band-width of about 3 percent. Feeding A Dipole With Ladder Line. In some instances it may be required to use a 1:1 Guanella choke. Particularly on 75 meters, getting a good match across the band can be impossible with a conventional half wave dipole fed with coax. It can be fed with standard 50 ohm coax. So, what does a 40m dipole consist of?. end to end 14awg. Resources listed under OCF Antenna category belongs to Antennas main collection, and get reviewed and rated by amateur radio operators. ~468 / freq in Mhz. I have an 80m inverted V dipole at about 50' and an 120-130 degree included angle and it performed great last weekend for SSB Sweeps. 5 dB This result confirms that the ground at W6GJB is quite poor!. SDR technology makes it possible that all listeners tune independently, and thus listen to different signals; this is in contrast to the many classical receivers that are already available via the internet. is tied last after final SWR adjustment and the antenna is in it's final position. Also, designs that do better on 80m, lack 15m. 2 dB 30 Ft +6. Adding a Director to a ¼ wave 40M HF vertical antenna. Although I'd suggest (say) 35 or 45 metres for better results on 80m. Adjust elements for resonance in order from lowest frequency to the highest. The OCF Dipole is a horizontal wire with a coaxial feed and coupling transformer (often called a balun) attached offset from the centre of the dipole. I would not recommend this for an attic with metal in it. Make offer - FD4 HF Dipole Antenna 80m 40m 20m 10m windom ocf wire balun unun multiband Ham Radio Pair of Antenna Traps 40/80m Low Swr and high efficiency. The OCF Flagpole really holds its own and is a stealth antenna, too! Look at the low-band (40/80M) results versus the 43′ vertical with radials. The most common half-wave antenna is the center-fed dipole, whose impedance is approximately 72 ohms. K1POO 4 Band Off Centre Fed Dipole (40-20-15-10m ) MMANA-GAL K1POO Antenna model’s 3D far field results The antenna at 8m height above real ground 5mS/m and dielectric 13, SWR ref 200Ω. Some people might take issue with using the word "dipole" because the antenna has more than two opposing polarities along the length, but in my opinion it is perfectly fine. If not, not so fine. Quick SWR Calculator for Vertical and Dipole Ham Radio Antennas Here’s a really simple way of double checking how to much to trim your antenna elements. ozaukeeradioclub. Tie your dipole feed lines together in the hamshack. I did consider an off center fed dipole but I wanted the flexibility of leaving the coax behind if needed, and it’s helpful to be able to use whatever length of wire is handy. I have over 15 antennas on the tower. The antenna is designed to be fed with 50 or 75 Ohm Coax Cable of most any length with a Balun. Buckmaster OCF Dipole Antennas. (Still using this balun, 35 years later, on a 10, 15, 20, 40, 80m trap dipole). However this gets trickier at lower installation heights. For RX I use an FT-1000D in AM mode with a PTS-250 for low side injection. 95 MFJ-1779A 160M DIPOLE, SINGLE BAND, 265FT $69. off center fed vertical dipole. This is an antenna that works without a tuner over the entire bandwidth of the 80, 40, 30, 20, 15 and 10m-band, simply by adjusting the output-tank of your tube power. It's also ideal for those who want a high performance antenna with world class DX coverage. Same, but instead of separate "counterpoise" wires, a steel tape-measure is used (33 ft x 1 inch = 10 m x 2. This year, I am running power which necessitates a different antenna last year (I used a 200w OCF dipole for 80m, 40m, and 20m). Buckmaster 8-band OCF Dipole Antenna, 300 Watts 270 feet long, 160 meters through 6 meters Buckmaster OCF Antennas are made from the best quality materials with a completely waterproof balun and no external connectors. 8 MHz) is exceptionally broad. In my case with the coax run at a 90 degree angle away from the antenna, this type of choke sufficed. 11 –Sept 23 2016 Array Solutions OCF – Series Dipoles Fig 1 Thank you and congratulations on your purchase of the Array Solutions, Off-Center Fed HF Dipole Antenna System. Cebik - W4RNL. DX-LB Low Band Dipole Covers 160-80-40 meters with an overall length of only 100 ft. The OCF Flagpole really holds its own and is a stealth antenna, too! Look at the low-band (40/80M) results versus the 43′ vertical with radials. Since most amateur bands. Dipole Antenna Calculator. 680 MHz with each leg 19. The RadioWavz DX (OCF) Windom is a off center fed (OCF) dipole antenna that exhibits outstanding performance on multiple bands typically without a tuner. The OCF/ Windom is an excellent antenna that will perform quite well, both on transmit and also receive. This is the length of a standard dipole but instead of dividing the result in half, use a 36/64% offset to determine the feedpoint. Remember that our 160M and 80M antennas are actually NVIS because most of us have height limitations under 70 feet. Homebrew 40/80 Trap Dipole Design This Antenna design was one that I used about 4 years ago, it worked exceptionally well on 80m and 40m. Using the EFHW for 20m at GB0CMS 3. Real Gain: Delivers a 6-dBi ground-rein-forced dipole pattern on the fundamental and a 9-dBi full-wave cloverleaf on the second harmonic. The difference with the short OCF is that it is less than λ/2 overall, and the feed is offset below the centre (and tube 8 is omitted, a different support is used) all of which results in the s/c stub being just λ/70 in length. 19 may 2011. The quality workmanship is far superior than others. I have no problem now with RF in the shack using the doublet. Running a wire up into a nearby tree and two “counterpoise” wires laying on the ground makes it happen for this AN/TRC-77 CW transceiver. 15 meters is a "bonus band" that will require a tuner. My property size limitation requires that each leg has a bend which runs. In the evening when most of us have time to relax and enjoy a little time on the radio, the higher frequency bands are either dead or very crowded. 80m Reduced Half Sloper. I did consider an off center fed dipole but I wanted the flexibility of leaving the coax behind if needed, and it’s helpful to be able to use whatever length of wire is handy. And I'm not sure I would define those lobes as something other than a compromise. The RadioWavz DX (OCF) Windom is ideal for those of you who do not use a tower and beam. The 3/2 wave 15 meter antenna (really the 40 meter dipole) has significant gain and is about 150Ω resistive depending on height. This is a center mast supported dipole. (Short side of ariel) use the same calculation as above though this time multiply the answer by. In Table 4 below I include the dimensions of 12 meter traps that could be used in the construction of such an antenna. Only thing I don't know is how long the vertical radiator has to be. 64 Construction and installation of a dipole for 80-, 40-, 15-, or 10-meters. But to your point, the off center fed dipole is a very effective antenna that is basically a more refined version of what i lay out in this article. The Wire Size can range from 16 AWG to 12 AWG. OCF Manual ver. It's a Spi-Ro LS-80K limited space 80-meter wire dipole. This article as well as this one best explain how and why this type of antenna works on multiple bands. Total length in feet. 10-80M HF base antenna ProMaster. For RX I use an FT-1000D in AM mode with a PTS-250 for low side injection. 5MHz and you get 130'. Buckmaster OCF Dipole Antennas. The G5RV length of feed line and antenna is the lower limit in size. This formula takes into consideration the capacitive "end-effect" from insulators which shortens the physical length requirement for the equivalent electrical length. As with the jumpered dipole, I recommend leaving a little extra wire to facilitate pruning. The second example is fairly easily rectified by simple adding or subtracting some length to either the dipole or the feed line, often as little as a metre will do the trick. 5 Attic OCF HZ Dipole. 80m End Loaded Trapped Dipole above steppir's boom 20. It is an off centre fed dipole, with 10 feet of vertical radiator. Off-center-Fed dipole Antennas is a curation of 13 resources about , OCF Dipole, The Six Meter OCF Sleeve Dipole Vertical, Center-Loaded Off-Center-Fed Dipole - 6 band, 80m OCF Dipole, Windom off center fed antenna 80-10 mt. 160 is a bit tricky and for small or low antennas a vertical over a good ground plane will always work better. The main category is Homemade projects for 80 meter Antennas that is about Antenna projects for 80 meters band. (• Windom(for(10(- 40(meters(shown. I have room for an full size 80m inverted vee hanging at about 35 - 40 feet from my tower. Except for a couple of Hamsticks, all of my antennas are homebrew. The bazooka worked well but was a single band antenna and I >would replace it after any 160M contest with either a Carolina Windom or a >80M delta loop. So a symmetrical antenna has to be the choice (so no verticals needing radials). MFJ-1778M JUNIOR G5RV, 10-40MHZ, 1500W, 52FT $44. Height of Choke RX Signal Center on ground -4 dB 6 In 0 dB 10 Ft +0. Long end of the wire (89 feet) is supported by a fiberglass pole about 12 feet agl. The G5RV antenna is a multi-band center-fed dipole antenna capable of 1500 Watts. 40 was noisy but I managed to work NV on both bands which is quite good from Maine. You can feed your dipole with coax, as already mentioned above. WATCH VIDEO at the best online prices at eBay!. We specialize in wire antenna systems. As seen on his page, the original formula seems to come from an article by J. NewSuperAntenna is the Official Super Antenna Systems Corporation website. Monoband Dipoles EA-80DXS, EA-60JR. While there are far too many things to cover here regarding SWR, I will offer some ideas on the subject. Some get away with less but some require more length. Feeding A Dipole With Ladder Line. Attached is a short article on this antenna that I’ve prepared. I believe it follows the dipole impedance vs height charts some what, only if the height is below half wave length. Referring to previous discussion, we know that the antenna impedance is not balanced with respect to earth. 5MHz and you get 130'. VK1AD WSPRLite beacon past 24 hours to 0945 UTC 26 March 2017 Radio amateur stations in Europe, North America, New Zealand and Australia who report receiving my 20m 100 mW WSPRLite signal. One would be a half-wave 20m and the second would be a half wave 80m. The bazooka worked well but was a single band antenna and I would replace it after any 160M contest with either a Carolina Windom or a 80M delta loop. The rule of thumb is, for a nice low take off angle you need to be 1/4 wave length or higher. MFJ-1778 - G5RV Wire Antenna - Multi-Band center-fed dipole antennas. 25=100 feet. Back to simple, quick and dirty. Tie your dipole feed lines together in the hamshack. 4 feet for the other leg. Add to cart here to purchase though Paypal. Buckmaster 8-band OCF Dipole Antenna, 300 Watts 270 feet long, 160 meters through 6 meters Buckmaster OCF Antennas are made from the best quality materials with a completely waterproof balun and no external connectors. The Wire Size can range from 16 AWG to 12 AWG. The normal Windom is described as having a 1/3 length leg, and a 2/3 length leg. So, an 80/160m trapped dipole will be an 80m dipole, with traps at the end of that, with additional wire to resonate it at 160m. I have tried 66-ft and it does not work as well as the 53-ft length here. Again, this is based on a feed point height of around 40 feet, inverted V configuration, normal soil conditions and no large nearby structures. I now have two OCF antennas in operation: a coax-fed 7-band 80m OCF for home use; a coax-fed 5-band 40m OCF for portable use. New Shack: Below are some pictures of my. I did consider an off center fed dipole but I wanted the flexibility of leaving the coax behind if needed, and it’s helpful to be able to use whatever length of wire is handy. I am planning to put up a full length 80 meter dipole. $\endgroup$ - WPrecht Nov 21 '13 at 20:15 2 $\begingroup$ A resonant folded dipole is not half the size as an ordinary dipole -- it is the same size, with twice the wire. Feeding A Dipole With Ladder Line. 40m 'Standard' half-wave Dipole Antenna (2nd HF antenna project) My 40m coaxial dipole antenna worked surprisingly well, considering how many compromises it was dealing with. 5 dBi peak gain on higher bands. 26 feet from one end. Perfect for building a dipole. For 40 and 80 meters the dipole will have a length which becomes difficult to hang up fully horizontal. I don't like that the G5RV has such a long length of ladder line. The idea is that for a given ham band there are min and max frequencies which are easily converted to half wavelengths by the famous 468/f generally used by hams for dipole lengths. I decided to try a OCF (Off Centerfed Dipole) dipole for the 160M contest this weekend rather than trying to put up the extended double bazooka I normally use. stacked folded dipole. But when I compared the actual gain figures at 10, 20 and 30 degrees elevation, the dipole, even when under 1/4 wave length high has more gain. All antennas are a compromise for multiband use, don't let others talk you out of trying what you want to do. 23-26 Step-by-step tutorial on constructing dipoles for any one of the HF bands from 1. My own experiments over the years have shown that, on 80m, this antenna will perform close to a full sized dipole for DX contacts, despite the small size, because of the low angle of radiation (30 degrees) and full size elements. I screwed a length of thin wall electrical metallic tubing (EMT) to the tree trunk and attached four heavy "screen door" springs to the EMT. I've used a 4:1 balun at 1/3 along or 17% off centre. how you plan to operate with it. The antenna is 180 degrees (half-wave) >on 80m and 360 degrees (full-wave) on 40m. Full 80m-band coverage. I am planning to put up a full length 80 meter dipole. The true OCF dipole must use. Apparently, OCF dipole designs had so far been a compromise between these three bands. installed in MFJ-347 mount. end to end 14awg. 40 M to 6 M OCF Spiral Dipole building Instructions The mechanical details of this antenna are must be followed to yield a ready to use antenna. A commercial antenna system, the Buckmaster 7-band OCF Dipole, exploits this property. The length of the 50Ω coax may help or hinder a match. 5 dB 20 Ft +3. The OCF dipole is a multi-band wire antenna that does not use traps and is relatively simple install. Dipoles need to be half a wavelength long, locating these long antennas can be an issue, especially when we are aiming for the 80 metre band or lower. UV insulated stranded wire. It was originally designed to operate as a 3/2 wavelength center fed antenna for 14 MHz, but amateurs soon discovered it would offer reasonable performance on many other bands. This offset gives the antenna the multi band capability. I have collected the questions and boiled them down to 10, all of which have many variations. On 40 and 20 the SWR is close to perfect. Coaxial fed Windom Antenna by SV1BSX The Windom is an Off-center wire multiband Antenna. A much better alternative to any of these three antenna designs is running the open-wire line from the center of a dipole all the way to a balanced antenna tuner, which was recommended by Louis Varney, G5RV himself. Calculations for the wire lengths can frequently hear the question: how high should my dipole be? Or alternatively, will my dipole work well at this or that height?. The half-wave dipole is very simple to construct. 36 to get the length in feet. You only need to type in the numbers in the Cyan boxes. BUILD THIS MULTIBAND FAN DIPOLE FOR ALL BAND HF ANTENNA EXCITEMENT Here is a fairly simple and easy to build multi band horizontal fan type dipole that can be constructed for all band operation from 160 meters up thru 6 meters or even higher.  So for 80m and up, you have one leg that is 45 feet long, and another leg that is 90 feet long. Antenna LENGTH 147 ft. OCF antennas are very convenient as they will allow multiple bands of operation with a simple wire antenna which is fed off center with a 4:1 OCF Current balun with built in feed line choke,. The classic OCFD is fedat 2/3 - 1/3 of the length Both a standard dipole and the. For an 80-10 meter OCF dipole antenna, start with a total length of 135. You can build anything but I don't think the OCF will work very well for 160 though. 6 MHz and you arrive at an overall length of 130'. 160-Meter Dipole Height N0GW - Gary Wescom - 1 Nov 2006 During the current lull in solar activity, operation on the 160 meter ham band has become more popular. Use as inverted vee or sloper to be more compact. Unlike many END FED antennas on the market, this one does not require the Antenna Tuner to operate. Some sources will suggest that the number is 3 to 5 percent shorter than the length of the dipole. 5 dB 40 Ft +9. UV insulated stranded wire. Lots of QRN on 80 and signals were weak. This is 1-1/2 inches diameter for most of the length with one end narrowed to 1-3/8 for about 6 inches. 80-10 Meter W7FG True Ladder Line Open Wire Fed Dipole 125' Dipole 100' Feedline 600Ω Open Wire Ladder Line One Conductor from Balun or Tuner to Far End Insulator. 19 may 2011. You can feed your dipole with coax, as already mentioned above. On 40m it was either equal to or one S point down on an 80m 132ft OCF Windom on EU signals – you can just see the long leg of that in the photograph. MFJ-1778 - G5RV Wire Antenna - Multi-Band center-fed dipole antennas. It's also ideal for those who want a high performance antenna with world class DX coverage. The length of a half-wave dipole might be thought to be the same as a half-wavelength of the signal in free space, but this is not quite the case. I found that OCF antenna impedance is also dependent on height. It can be designed for use from 160 thru 10 meters very easily using the standard 1/2 wave dipole formula: 468/freqmhz = total length (ft) end to end The exact length is not critical! If you don't have room for the 160 or 80 meter versionthen design it for 40 meters and up!. It can be fed with standard 50 ohm coax. For an 80-10 meter OCF dipole antenna, divide the ½ wavelength standard of 468 by the lowest operating frequency of 3. I had the ends of the 40m dipole fan out to a separate trees; kinda like an "X" with a serif on one leg. Total length in feet. Although the traditional OCF dipole had very broad band-segments, the VSWR-minima of either the 80 m or the 40 m-band could not be perfectly aligned to the respective band-centers. The interesting thing is that it is multi banded with no traps. Be sure to put a 4:1 CURRENT balun at the top feed point. His Youtube video seems to have been substituted with one by Portune, so I have removed the link. It is full length 10m - 20m and there is some loading for 30m & 40m. This is the length of a standard dipole but instead of dividing the result in half, use a 36/64% offset to determine the feedpoint. EFHW-8010-1K Multi-Band End Fed Half Wave Antenna. The center of the antenna should not be higher than λ/4. The OCF-3K80 dipole will work well on the 80, 40 ,20, 17,12, and 10 meter ham bands with no need for tuning. Its’ feed-point affects its impedance. It is an off centre fed dipole, with 10 feet of vertical radiator. As the Capacity hats get larger, the resonant length shortens In the article, Rudy models a traditional full size 80m 1/4 w/l with 4 elevated radials.  So for 80m and up, you have one leg that is 45 feet long, and another leg that is 90 feet long. Probably not high enough. [TowerTalk] 160M OCF Dipole Length. These two steps tamed the excessive CMC on the feedline and gave me a 7-band antenna; 8-bands if you use a matchbox on 17m. Introducing the "All-Band" Doublet: What the Student and the Instructor Should Keep in Mind L. Overall length is 40 ft. The length of the 50Ω coax may help or hinder a match. The previous 80m antenna was de-tuneing the SteppIR and so one of the requirements are to have no resonance at any other frequency. how to build a dipole antena The simplest and easiest way to produce antenna for hf. So for 80m and up, you have one leg that is 45 feet long, and another leg that. length of a full vertical dipole. The RadioWavz DX (OCF) Windom is a off center fed (OCF) dipole antenna that exhibits outstanding performance on all bands. MFJ-1778M JUNIOR G5RV, 10-40MHZ, 1500W, 52FT $44. All-Band Doublet L. 6 MHz and you arrive at an overall length of 130'. #1 Falcon 80-6 Meter Off Center Fed Dipole Amateur Ham Radio Antenna is constructed with the full particulars for your appliance in use. Then I have about 15' of coax that screws to the match box and I run it into my car window to my operating position in the drivers seat. It all depends on of available room you have to install this antenna. On 40m, we are feeding it with 3/4 wavelength of ladder-line. Dipoles antennas are easy to build and can be very effective when placed half a wavelenth or more above ground. com/profile/17915214783252422292 [email protected] I use an 80m dipole with an MFJ 949D tuner. Too low to really get much from a yagi (or a dipole for that matter), but I have had a 5-band hex-style beam on that same pole from October 2002 to May 2003 and was able to compare it to the spider on the back lawn (3 feet high in the test stand). 468 ÷ freq (mHz) = Length (feet). 19 may 2011. 14 or (14%). The center of the antenna should not be higher than λ/4. Another way to say this is a 100 delta SNRs comparing a full length. 95 MFJ-1780X BOX FAN PORTABLE LOOP ANT. Last year on Field Day I was able to use an OCF dipole for the first time, and I enjoyed the quick bandswitching it allowed, so I thought I'd try and find a good OCF dipole for use while in the field. The TZ-OCF-80 is an Off Center Fed wire antenna designed to permit operation on the 80m, 40m, 20m and 10m amateur bands. Half-wave dipole antennas are great but can be a pain with the initial tuning; up, down, trim, up, down, trim, up, down, trim, etc. 00: FSDP12Q. 43 ft and 86 ft with 30 ft and 60 ft gives us decent results on 80 through 40. Quickly switch bands and eliminate a tuner as one more thing to adjust. The radiator is made from 2mm diameter copper braid, the black PVC coating is UV resistant. Then I have about 15' of coax that screws to the match box and I run it into my car window to my operating position in the drivers seat. 25=200 feet. end to end 14awg. OCF Dipole 7 band 80-6 meters Poly-Stealth Antenna 7-Band: 75/80, 40, 20, 17, 12, 10, & 6 meters. Every Antenna is cut to a precise length to accomodate that particular band. Attached is a short article on this antenna that I’ve prepared. The apex on my OCF is 10m AGL. R`s it is fed with 85 or so feet of LMR-400 coax. That’s right… an all-band link dipole! Since my dipole will be at ‘lower than optimal’ heights, I’ve decided to construct a 1:1 guanella current balun for this task. 80-10 Meter W7FG True Ladder Line Open Wire Fed Dipole 125' Dipole 100' Feedline 600Ω Open Wire Ladder Line One Conductor from Balun or Tuner to Far End Insulator. 2% relative bandwidth the 80 m-band (3. I have no problem now with RF in the shack using the doublet. While the antenna is well less than a half wave length at 1. 6 MHz, take 468 / 3. The lower the antenna the lower the impedance of the feed point. Perfect for building a dipole. This style windom has a 4:1 balun and is rated for 2KW. As I mentioned earlier, more shortening will not compromise gain or wave angle much at all, but it will reduce the bandwidth. Apparently, OCF dipole designs had so far been a compromise between these three bands. neither dipole leg is a multiple of a half-wavelength. The 3/2 wave 15 meter antenna (really the 40 meter dipole) has significant gain and is about 150Ω resistive depending on height. 40 was noisy but I managed to work NV on both bands which is quite good from Maine. As I mentioned earlier, more shortening will not compromise gain or wave angle much at all, but it will reduce the bandwidth. Wire Antennas for Ham Radio Short Dipole Antenna for 40m - 80m - 160m 31 51. Study of the Off Centre Fed Dipole Antenna - G8ODE Short Long Feed point The Off Centre Fed Half-wave Dipole The Off-Centre Fed Half-Wave Dipole, more commonly referred to as the OCFD, is very popular because it offers good performance as a multi-band antenna using an antenna matching unit in conjunction with a 4:1 or 6:1 current balun. 2x10 M (2x33 FT) MID-LOADED DIPOLE. OCF (Off-Center Fed) Dipole for 80m and 40m Carl Luetzelschwab K9LA October 2019 This month is another break from tradition in that I won't be talking about solar issues or ionospheric issues or propagation. It can be fine tuned for lowest SWR just like a dipole antenna can. The dipole antenna is said by many to be the perfect antenna for a specific frequency. The antenna can be erected as horizontal dipole, as sloper, or an inverted-V antenna. a dipole as well. Full size dipole for 40 meters @ 70 feet long: $42. The first step in constructing my Carolina Windom was to cut the antenna wire to length for an 80 meter version. BUILD THIS MULTIBAND FAN DIPOLE FOR ALL BAND HF ANTENNA EXCITEMENT Here is a fairly simple and easy to build multi band horizontal fan type dipole that can be constructed for all band operation from 160 meters up thru 6 meters or even higher. If the lobe is in a good place for you, fine. Another shot of the setup.