80m Ocf Dipole Length

shack and I switched between my Fritzel OCF (off centre fed) 80m – 10m dipole for a few evenings rx just to see how it performed. Antenna performance and 2:1 VSWR bandwidth is site dependent and varies with height above ground and surrounding objects. Despite all the words and diagrams in handbooks over the years, newcomers still send me questions about the antenna. The San Antonio Radio Club Field Day 2019!! The go-to antenna was our OCF-3K80 Multi-Band dipole. The antenna consists of asymmetrical length horizontal radiating elements being driven at the feedpoint through a 4:1 broadband Balun and a 50 Ohm Coaxial cable. This formula takes into consideration the capacitive "end-effect" from insulators which shortens the physical length requirement for the equivalent electrical length. You can attach the ladder line to one side of the. 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. G5RV or 135 foot doublet or Carolina Windom? handy to let you work the whole 80m band, once you are It's no secret I not a fan of windoms or any OCF dipole. 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. 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. UV insulated stranded wire. On 40 and 20 the SWR is close to perfect. Turns out that there is a different number often cited for inverted vees. So, I started modeling one. The attainable bandwidth (SWR equal or better than 2:1) is 120 kHz on 80m, approx. The performance is very good across the HF bands and requires little or no tuning. The antenna can be mounted as a dipole or inverted vee. Normally you divide that in half to find the center feed point; however, we are feeding this 14% off-center, so add 14% to 50% and you get 64% for the longest leg which leaves 36% for the shortest leg. Also, worth noting is the pattern breaks up on 10M on the 43'er. 197 Click Here to Email-- Click Here to View Picture-- Send this Ad to a Friend WTB DX Engineering 80M Vertical Wanted DX Engineering 80M Vertical. I found that OCF antenna impedance is also dependent on height. The 3/2 wave 15 meter antenna (really the 40 meter dipole) has significant gain and is about 150Ω resistive depending on height. Here is a formula and calculator for creating a loaded (shortened) quarter wave vertical or balanced dipole. Made to last. The RigExpert and laptop are on the table under the umbrella. I was toying with the idea of a 160-6M OCF dipole. 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. Not many folks on 20. The 80m dipole was already on its 48 foot mast with a DX Engineering balun and original coax. I started constructing one of these but soon came to realise that the balun was a compromise. DIPOLE FOR 40 AND 15 METERS WITH MATCHING SECTION FOR LOW SWR ON 15 METERS. 43 ft and 86 ft with 30 ft and 60 ft gives us decent results on 80 through 40. FD4 HF Dipole Antenna 80m 40m 20m 10m windom ocf wire balun unun multiband | Consumer Electronics, Radio Communication, Antennas | eBay!. My first home brew antenna was an 80m dipole with ferrite 1:1 balun in 2" PVC tube. Adjust elements for resonance in order from lowest frequency to the highest. More detail at 80M, the primary frequency of the antenna. These 2 dipoles are at right angles to each other and the 20/15 dipole is located about 6 feet below the 75/40/20 fan dipole. This year, I am running power which necessitates a different antenna last year (I used a 200w OCF dipole for 80m, 40m, and 20m). It is 30 ft. The OCF dipole is a multi-band wire antenna that does not use traps and is relatively simple install. The SWA-148 dipole includes 65 feet of high quality 300 Ω ladder line used for the feedline. Tie your dipole feed lines together in the hamshack. half wave dipole antenna calculator. This was the maximum height I could live with. The OCF/ Windom is an excellent antenna that will perform quite well, both on transmit and also receive. However, any OCF dipole easily. 80m version also available contact us. The center of each Tee should be joined to the end of each of the dipole main elements. Long end of the wire (89 feet) is supported by a fiberglass pole about 12 feet agl. Cebik, W4RNL. These Alpha Delta amateur antennas use a no-trap design (except DX-LB). The RadioWavz DX (OCF) Windom is a off center fed (OCF) dipole antenna that exhibits outstanding performance on all bands. February 7 of 2010 was a quiet Sunday. 2 MHz, here’s how to make it. MFJ-1778M JUNIOR G5RV, 10-40MHZ, 1500W, 52FT $44. The G0KYA EFHW – an end-fed half wave monoband HF antenna, plus two multiband versions (New!) A practical, cheap monoband or multiband (new!) vertical antenna that is great for DX and very cheap to build. This was the maximum height I could live with. Cumbersome cage dipoles or load switching arrangements deliver only partially satisfactory results. 6 MHz and you arrive at an overall length of 130'. The San Antonio Radio Club Field Day 2019!! The go-to antenna was our OCF-3K80 Multi-Band dipole. It can be fed with standard 50 ohm coax. Design Parameters. If you can, build it yourself. A simple 80m dipole was modeled at 3. 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 most common half-wave antenna is the center-fed dipole, whose impedance is approximately 72 ohms. The OCFD in incapable of harmonics. 80m Reduced Half Sloper. You can build anything but I don't think the OCF will work very well for 160 though. This type of antenna is suitable for single band, narrow bandwidth use. The lower portion of Figure 2 shows a detail of the dipole extended to its full length. The only can be tweaked to work on frequencies near even thing they share is the fact that neither is fed at the harmonics. com/profile/17915214783252422292 [email protected] When length is greater than 100 times diameter the antenna can become non-self-supporting and is probably too high anyway. Generaly speaking, due to the ease of setup, its low profile and its very attracting price, the dipole is the most used antenna, and not only in the field or for portable operations. This is an End-Fed Half-Wave (EFHW*) antenna for 80/40/30/20/17/15/12 and 10m bands. It is a great antenna for HAM radio operators living in HOA controlled housing, hams desiring a very stealthy RV antenna, Field Day operations, sailboats, portable operating. 2% relative bandwidth the 80 m-band (3. 43 ft and 86 ft with 30 ft and 60 ft gives us decent results on 80 through 40. I have other antennas deployed, but I do like the wide coverage it offers. Probably not high enough. DX-LB Low Band Dipole Covers 160-80-40 meters with an overall length of only 100 ft. An 80m length of wire will do 80, 40, 20, and 10 (not 15) (and 6 too), all with nearly the same feedpoint impedance. 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 try not to suffer in retirement!. The RadioWavz DX (OCF) Windom is ideal for those of you who do not use a tower and beam. A typical OCF dipole is fed at 1/3rd of its length. The length of most commonly used half wave dipole antenna is half the wavelength of your signal in question. 95 MFJ-1779C 20-6M DIPOLE, SINGLE BAND, 35 FT $29. The OCF-3K80 is complete with a 4 to 1 -- 3000 Watt continuous duty Balun. 40 meter dipole between two 80' towers, 4 element SteppIR in bi-direction mode for 20 meters. Eliminate send/receive tuner loss. multiband hf dipole antenna. WATCH VIDEO at the best online prices at eBay!. The Buddipole™ - HFportable dipole antenna system, Welcome to the home of the Buddipole™, an hf/vhf portable dipole antenna system which is designed to be modular, versatile, and efficient. 10-80m antenna requiring 40ft vertical height and 90ft of lateral length and 70ft min. The OCF will never have the gain. design, OCFD antennas work on even harmonics and They are in no way the same antenna. I've used a 4:1 balun at 1/3 along or 17% off centre. 160 is a bit tricky and for small or low antennas a vertical over a good ground plane will always work better. However it's performance was best on the higher bands and on 40m never achieved a reasonable SWR without an ATU to help. 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. Full 80m-band coverage. It seems to work just as well or better as the 40m/30m fan dipole on those two bands. It started out as a dog leg 80m dipole at around 20 feet. This is a must for receive purposes too and it can easily compete vs multi-band verticals or beam due to its less sensitivity to QRM and pick-up efficiency. A equipment that has a complex gustatory. A simple and tidy way to store half of the antenna when it is not in use, two are required for dipole and OCF arrays Made from UV resistant cast acrylic sheet to NBS Antennas specifications. 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. A commercial antenna system, the Buckmaster 7-band OCF Dipole, exploits this property. A compari-son to a standard dipole is shown in Fig 5. 5:1 on 6, 10, 20, 40 & 80m bands and can be. Despite all the words and diagrams in handbooks over the years, newcomers still send me questions about the antenna. Full wave length loop (not practical for most of us) Half wave length dipole with the feed point lower than the ends yet about fifteen foot height. The antenna consists of asymmetrical length horizontal radiating elements being driven at the feedpoint through a 4:1 broadband Balun and a 50 Ohm Coaxial cable. On 40 and 20 the SWR is close to perfect. 95 MFJ-1779A 160M DIPOLE, SINGLE BAND, 265FT $69. Particularly on 75 meters, getting a good match across the band can be impossible with a conventional half wave dipole fed with coax. The apex on my OCF is 10m AGL. Another way to say this is a 100 delta SNRs comparing a full length. The MMANA-GAL model of the K1POO antenna at 8m height shows that the antenna has a more complex lobe structure as the frequency increases. Jeff , VE1ZAC This is not a new idea, but the method I am suggesting of doing it is novel, and possibly simple to implement ! The caveat is that it is fussy and unique to each antenna situation. Antenna Length: 77 ft. Below is one example of how to build and mount a 40 meter loaded dipole using basic materials. 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. 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. The height above ground will affect the feed point impedance and the transformation ratio of the balun. Also, worth noting is the pattern breaks up on 10M on the 43’er. Use as inverted vee or sloper to be more compact. Thank you guys, for choosing Maxcon!!! Thank you, Rosendo Guzman, N5YBG, for sharing the Photos!!. Turns out that there is a different number often cited for inverted vees. The picture on the right above shows an OCF Dipolewith the feedpoint positioned at the same feedpint of the classical WINDOM antenna, fed with 50 Ohm coax through a 4:1 or 6:1 balun at a point 1/3 of the distance from one end. Can be used as a off center fed shortwave antenna to provide continuous coverage from 500 kHz to 60 MHz. The antenna tuned successfully from 6-80m bands with SWR below 1. I decided to build a 80 meter, half wave wire antenna that takes full advantage of the phone portion of the band known as 75 meters, also this antenna will not need a tuner. First off you have to know that I didn’t invent this. OCF Dipole 7 band 80 -6 Rick on 27th Mar 2018 You are not going to find a better antenna than this one. fundamental frequency, including 80, 40, 20, 10 and 6 m bands. That’s all there is to it. I try not to suffer in retirement!. Ham Radio Dipole Transmission Line. If a 135 foot OCF were compared to a 1/2 wave 160 meter dipole, the OCF would lose, but if it were compared to a 20 meter dipole, it would have gain in the direction of various lobes. Place a 1:1 Balun on the Antenna end of the Feedline. It can be sus-pended from any convenient support, rolls up into a tiny space and makes a good Field Day antenna. 12m ex-military Light Duty push-up telescopic mast 19. It's a Spi-Ro LS-80K limited space 80-meter wire dipole. So the measurements are based on a 40 meter 1/2 wave dipole. I hope that this post provides some useful ideas for HAMs contemplating the installation of their first HF antenna. The counterpoise is 16-ft long and the main element and counterpoise are suspended as a dipole. Joe Petrucce. The key feature of my stand is the unique reversible upper section. The dipole-doublet’s length in feet matters less than how long the doublet is at a given operating frequency in terms of half-wavelengths. Lots of QRN on 80 and signals were weak. But it turns out, If I make the long end of the 80-6m OCF the short end of the 160-6m OCF, and add the required length to short end the long end of a 160-6M OCF, It would be the same. Made with stranded 14 awg UV insulated wire. The G7FEK 10-80m Garden Antenna. Monoband Dipoles EA-80DXS, EA-60JR. Buckmaster OCF Dipole Antennas Buckmaster's Best Coaxial Cables Antenna Support Rope Stringliner Reel with 270 feet of Twisted Nylon Line Harken Stainless Steel Pulleys Line-Grips RF Chokes CQ Magazine Archives Great Circle (Azimuthal Equidistant) Maps World Prefix and Worked All States (WAS) Maps HamCall Mousepads Custom Name Badges Amateur. It is a great antenna for HAM radio operators living in HOA controlled housing, hams desiring a very stealthy RV antenna, Field Day operations, sailboats, portable operating. The maximum frequencies involved will be as low as 1. Add to cart here to purchase though Paypal. Expect ham radio confidence with the DX Flagpole and it’s Vertical Dipole cousins down to 80M! Q. Adjust elements for resonance in order from lowest frequency to the highest. 5 dB This result confirms that the ground at W6GJB is quite poor!. 5 dBi peak gain on higher bands. In the case of the Tee selection, the length given is for each of the two main elements AND each of the Tees; each side of the Tee is half the length of each main side. 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. It all depends on of available room you have to install this antenna. Some sources will suggest that the number is 3 to 5 percent shorter than the length of the dipole. installed in MFJ-347 mount. 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!. Perhaps too many new hams embarking on their first HF adventures think only of resonant dipoles fed with coaxial cable and plugged directly into the transceiver's output connector. Also, worth noting is the pattern breaks up on 10M on the 43’er. <21:01:39>"George - N2APB": "The modern common Windom antenna is not an original single-wire fed Windom, but rather an off-center-fed or "OCF" two wire feed dipole. 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. Note that I only use this antenna on 75/80M - - - on 40M I have a 40M Rotatable Dipole up about 65', and on 10-12-15-17-20M I use a 8-element Tennadyne Log Periodic antenna. After working with the 40M Dipole for a while it does not appear to work very well for DX. It's also ideal for those who want a high performance antenna with world class DX coverage 80, 40, 20, and 10 meters. 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. After extensive testing, the power rating on the W8AMZ 80m Reduced Half Sloper antenna has been increased to 1 KW SSB! ( 1000 Watts into a properly tuned antenna at or near resonant frequency, lowest swr and X ≈ 0. So, I started modeling one. 12m ex-military Heavy Duty pneumatic telescopic tower 18. Field Test of 20M Vertical Dipole Over 5 Mile Path. I am sure it is going to depend on the station I am trying to work, I imagine some will work better on the vertical and some on the horizontal dipole. The length of most commonly used half wave dipole antenna is half the wavelength of your signal in question. The length of the monoband dipole is long enough to be tuned to the lower end of the band (CW range). The antenna length should be about a half wavelength at the lowest frequency of interest for best results. Buckmaster OCF Dipole Installation Diagram (Courtesy Buckmaster) The OCF dipole is usually installed in an inverted-V configuration so the ends do not need to be very high off the ground (~10 ft is good). , about ¼ wavelength. Antenna performance and 2:1 VSWR bandwidth is site dependent and varies with height above ground and surrounding objects. The G5RV antenna is a multi-band center-fed dipole antenna capable of 1500 Watts. 80m vertical folded dipole. A number of effects, including the velocity factor of the wire, the length / diameter of the wire used for the radiating element and capacitive end effects, mean that the actual length required is a. That antenna will work on ANY band from 80 through 10 meters. There are thousands of happy inverted-L users around the world. This type of antenna is suitable for single band, narrow bandwidth use. 5db below the "saggy" dipole above!) Random length wire "Dual Ham-stick" dipole Antenna below 4 feet high. Monoband HF Dipole Antenna (89,852 bytes, PDF file) QST April 1993, p. This is a variable length that requires some experimentation. 5 Attic OCF HZ Dipole. It can be fine tuned for lowest SWR just like a dipole antenna can. 6, 10, 12, 17, 20m & 40m WITHOUT a tuner, and 15, 30, 60m & 80m with a tuner. 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. 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. 2 dB 30 Ft +6. Overall length is 40 ft. It seems to work just as well or better as the 40m/30m fan dipole on those two bands. DIPOLE FOR 40 AND 15 METERS WITH MATCHING SECTION FOR LOW SWR ON 15 METERS. 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. Dipole Antennas - the Effect of Height Above Ground I frequently hear the question: how high should my dipole be? Or alternatively, will my dipole work well at this or that height? Unfortunately, these questions can not be answered without first stating what you want the dipole to actually DO, i. 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. Band width:80m,40m,20m,10m Typically with out a tuner. The springs running to the left and right in the picture apply tension to the insulators that are attached to the North and South legs of the dipole antenna. How well and antenna works is a difficult question to answer. Below is one example of how to build and mount a 40 meter loaded dipole using basic materials. They had 3 of our OCF-3K80 antennas in use. I cut a 40m dipole to around 65 feet long, and married it to the 80m dipole. Buckmaster OCF Dipole Antennas are made from the best quality materials with a completely potted waterproof balun and no external connectors. I just tested one out yesterday, where I start with a 40m dipole and add loading coils and extension wires. It is [possible to add a 40M version of the 2-element half-log-cell antenna INSIDE the 75-80M. New Shack: Below are some pictures of my. It's fairly close to the ground so I'm not suprised it's SWR on 80 is a little high but still useable. As with the jumpered dipole, I recommend leaving a little extra wire to facilitate pruning. 80m Windom (OCF Dipole) hung from the peak of the roof The line heading to the window is just rope that goes into the window so that I can pull it back to work on it, detach it, etc. 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. Be sure to put a 4:1 CURRENT balun at the top feed point. The main lobe is now 43° wide at the 3-dB points,. 2x10 M (2x33 FT) MID-LOADED DIPOLE. The G5RV length of feed line and antenna is the lower limit in size. The lengths of the dipole legs should be in a ratio of between about 2:1 and 3:1 to provide tunable impedances for the ATU. Barnsley South Yorkshire. Band width:80m,40m,20m,10m Typically with out a tuner. It's also ideal for those who want a high performance antenna with world class DX coverage 80, 40, 20, and 10 meters. The normal Windom is described as having a 1/3 length leg, and a 2/3 length leg. Band width: 160m,80m,40m,20m,10m Typically without a tuner. The 80m dipole was already on its 48 foot mast with a DX Engineering balun and original coax. This is an End-Fed Half-Wave (EFHW*) antenna for 80/40/30/20/17/15/12 and 10m bands. 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. Normally you divide that in half to find the center feed point; however, we are feeding this 14% off-center, so add 14% to 50% and you get 64% for the longest leg which leaves 36% for the shortest leg. 64 to get the length in feet. The antenna features. Our wires start at 44 feet but longer length is recommended for coverage of 80m or even 160m band. The RadioWavz DX (OCF) Windom is a off center fed (OCF) dipole antenna that exhibits outstanding performance on all bands. A feed line is attached to an optimum point along the dipole by a BALUN. 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. R`s it is fed with 85 or so feet of LMR-400 coax. It works surprisingly well for the center only being 17 feet high. Expect ham radio confidence with the DX Flagpole and it's Vertical Dipole cousins down to 80M! Q. 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. folded dipole array. Every Antenna is cut to a precise length to accomodate that particular band. 10 Customer Reviews. The springs running to the left and right in the picture apply tension to the insulators that are attached to the North and South legs of the dipole antenna. 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. The antenna can be mounted as a dipole or inverted vee. The maximum frequencies involved will be as low as 1. 85 feet of insulated wire and place the offset at 39. The interesting thing is that it is multi banded with no traps. An 80m length of wire will do 80, 40, 20, and 10 (not 15) (and 6 too), all with nearly the same feedpoint impedance. Eliminate send/receive tuner loss. For this 2/3 antenna, the bandwidth is still very reasonable, though, Figure 7. (hopefully I pass my general this weekend so I can use it). Initially nothing worked. High current, low voltage at center; low current high voltage at ends. Overall length from tip to tip is about 13″. Another way to say this is a 100 delta SNRs comparing a full length. Perhaps too many new hams embarking on their first HF adventures think only of resonant dipoles fed with coaxial cable and plugged directly into the transceiver's output connector. Quickly switch bands and eliminate a tuner as one more thing to adjust. 48 feet) and 65. Thank you guys, for choosing Maxcon!!! Thank you, Rosendo Guzman, N5YBG, for sharing the Photos!!. 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. folded dipole. Turns out that there is a different number often cited for inverted vees. I just tested one out yesterday, where I start with a 40m dipole and add loading coils and extension wires. Made to last. I use an 80m dipole with an MFJ 949D tuner. My Experiment in Building a Vertical Dipole Antenna: This project came about when I decided to pull out an old Corba 148 GTL cb I have had in storage for many years. 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 height above ground will affect the feed point impedance and the transformation ratio of the balun. This year, I am running power which necessitates a different antenna last year (I used a 200w OCF dipole for 80m, 40m, and 20m). They were using the call: W5SC. Off-centre-fed dipole (OCF dipole) As the name suggests, the OCF dipole is not fed from the centre. If you do get RF problems in the shack make sure you have a good earth (see earlier). 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. 25=100 feet. Some as low as 20 ohms. Off-Center-Fed Dipole, OCFD, Windom. In all of the above cases, there was 50Ω cable between the matching ladder line section and the 50Ω transmitter. An Improved Multiband Trap Dipole Antenna You need this—traps with lower loss, higher Q, increased power-handling capability and four-band coverage! By Al Buxton, W8NX This improved multiband trap dipole introduces a new trap design and a change in trap location. I moved to Florida (The Villages) in October of 2018. Halfwave Reflector is: 126. 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. Multi-Band Dipole I built a multiband dipole that will work and 10 meters for ham radio. The Short Dipole - There are several ways to reduce the length of a dipole and still use it as an effective antenna. 14 or (14%). This antenna was built with the same quality workmanship and attention to detail as our military, government and commercial wire antenna products. This type of antenna is suitable for single band, narrow bandwidth use. For RX I use an FT-1000D in AM mode with a PTS-250 for low side injection. I present to you, The OFFSET CENTER Fed Dipole! A 40 meter OCFD is 66' overall length, same as a 40 m center fed dipole. Turns out that there is a different number often cited for inverted vees. Also, designs that do better on 80m, lack 15m. Here is another model with coaxial feeder, which is compatible with Solid States - 50 Ohm output transceivers. The apex on my OCF is 10m AGL. Try inserting a short length jumper (3 ft) to see if the rig's built in tuner will match. A SWR meter will not provide enough information for trim tuning or feed point adjustments. However this gets trickier at lower installation heights. Here is my home HF antenna. On 40m, we are feeding it with 3/4 wavelength of ladder-line. Unlike many END FED antennas on the market, this one does not require the Antenna Tuner to operate. Since the resonant length of a given element in the presence of the others is not the same as a dipole by itself, tuning can be a tedious and difficult procedure. The 3/2 wave 15 meter antenna (really the 40 meter dipole) has significant gain and is about 150Ω resistive depending on height. Note that I only use this antenna on 75/80M – – – on 40M I have a 40M Rotatable Dipole up about 65’, and on 10-12-15-17-20M I use a 8-element Tennadyne Log Periodic antenna. 80m Windom (OCF Dipole) hung from the peak of the roof The line heading to the window is just rope that goes into the window so that I can pull it back to work on it, detach it, etc. I am using MFJ hamsticks for 20m and 40m bands in dipole configuration(s), i. Joe Petrucce. This link is listed in our web site directory since Sunday Oct 13 2013, and till today "80m OCF Dipole" has been followed for a total of 1644 times. On 75m, we are feeding the antenna with a half-wavelength of ladder-line. The antenna can be mounted as a dipole or inverted vee. An off center fed (OCF) dipole fed at the 1/3-2/3 point is resonant based on total length, and instead of a 75 ohm feed point they have anywhere from 200 to 600 ohms. My Experiment in Building a Vertical Dipole Antenna: This project came about when I decided to pull out an old Corba 148 GTL cb I have had in storage for many years. 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 antenna features. Jerry --- or anyone --- does anyone know the toroids used and the turns ratios etc? I managed to create a version of the popular Buckmaster OCF dipole recently and was pleasantly surprised at how well it seemed to work. ozaukeeradioclub. This is the non-resonant 80m and 60m OCF dipole developed from the parasitic design above fed at the same 33% point. They cover all bands from 80-10 meters with a wide range antenna tuner. 19 foot eighthwave Halfwave wire dipole is: 120. Band width:80m,40m,20m,10m Typically with out a tuner. The Short Dipole "On Coils" There is very popular method of making a short dipole ("physically shorter than normal" half-wave dipole) resonate at a given frequency. 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. 4 20m erweld wire Nylon rope o n of I lament Tension ropes each side 32. I attached a porcelain egg insu-lator to the far end of the dipole (left end of. In the case of the Tee selection, the length given is for each of the two main elements AND each of the Tees; each side of the Tee is half the length of each main side. The antenna length should be about a half wavelength at the lowest frequency of interest for best results. The interesting thing is that it is multi banded with no traps. I have no problem now with RF in the shack using the doublet. Tuning the antenna is simple. 2EØZEH has built a 40-m OCF dipole and would like to add an extension for 80-m. The length calculation being 492/freq (in feet); 150/freq (in meters). They are very simple and inexpensive. end to end 14awg. So I'm no longer using this attic antenna for 80m but it's working great for 40m and above. Here is a formula and calculator for creating a loaded (shortened) quarter wave vertical or balanced dipole. 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. Lots of QRN on 80 and signals were weak. 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. Buckmaster OCF Dipole Antennas are made from the best quality materials with a completely potted waterproof balun and no external connectors. Try inserting a short length jumper (3 ft) to see if the rig's built in tuner will match. In this example we want the length to have the lowest SWR at 7. All antennas are a compromise for multiband use, don't let others talk you out of trying what you want to do. 2% relative bandwidth the 80 m-band (3. vertical folded dipole antenna. 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 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. The antenna is 180 degrees (half-wave) >on 80m and 360 degrees (full-wave) on 40m. DX-LB Low Band Dipole Covers 160-80-40 meters with an overall length of only 100 ft. SWR is less than 1. The OCFD in incapable of harmonics. I've just put up a OCF dipole for 80m and above. As with the jumpered dipole, I recommend leaving a little extra wire to facilitate pruning. THE OCF FD4 (FD3) WINDOM ANTENNA. 8 MHz) is exceptionally broad. Due to the fact that one wire leg of the antenna is shorter than the other, the OCF is more convenient to erect than a regular center fed dipole. The Matching Section is 450 Ohm Open Wire Feedline and is a compromise impedance between the 5/8 Wave antenna elements and the feed point, A 4:1 Current Balun.