160m Ocf Dipole Measurements

85 feet of insulated wire and place the offset at 39. The Balun matches the Balanced Antenna into the Unbalanced Coax Cable. If I only have the budget for one HF antenna, should I chose a vertical or a horizontal antenna? Stack Exchange Network Stack Exchange network consists of 175 Q&A communities including Stack Overflow , the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. How Much is Height Worth? For an 80M horizontal dipole (or Yagi) at 15° and below 0. The 160m OCF Dipole. hf multiband. 1 - 40m dipole broadside gain patterns vs. If this is a Standard Double Bazooka or Shorty Double Bazooka this procedure must be performed on each side of the antenna. Sloping Dipole Antenna 11 16. Off Center Fed Dipole – Feed point is 20-33% from one end. 8% for one side and 62. The coax should be perpendicular to the antenna for at least the first 1 m (3-4 ft). Note: It is not imperative to feed the OCF antenna at the point shown. Covers all bands, 160-10 Meters with antenna tuner. The optimum height for 160m antennas for any purpose is almost always a lot higher than anyone can actually install them. Suppose further that this antenna is to operate at f =3 MHz, and that the metal is copper, so that the conductivity is 59,600,000 S/m. The picture on the right above shows an OCF Dipole with 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. Made to last. I am not sure if the same would. How Much is Height Worth? For an 80M horizontal dipole (or Yagi) at 15° and below 0. The RadioWavz DX (OCF) Windom is ideal for those of you who do not use a tower and beam. MFJ 259B antenna analyzer 2 Homebrew interfaces for RTTY and PC Control. 5 dB for λ/8 (33 Ft) to λ/4 (67 Ft) 6 dB for λ/4 (67 Ft) to λ/2 (133 Ft) On the lower bands, we need less signal to work short distances than long distances An antenna cannot be “too high” for 80M. The shapes of the 6, 12 and 24 foot high antenna patterns differ only in gain, but maintain the same basic shape. vertical folded dipole antenna. To compare an OCF Dipole with an end-fed: I bought a well-known EFHW 80-6 M antenna and put it up at the same height almost side-by-side with my 80-6 M OCF dipole. Anyway, after calculating the dimensions, I put up this OCF > dipole using insulated #14 wire I got from the Wireman at the Orlando > Hamcation. com FREE DELIVERY possible on eligible purchases. Understanding And Building The OCF Dipole by Ron Bertrand. Linearly Loaded Tee Antenna 17 27. New countries are JT5DX, Z6ØA, ZC4A, 4U1A, 4U13FEB. The apex is at about 25 feet, and the short side terminates at the same height. I supported it from the center of a small tree in my back yard at a height of about 18 feet. There's a lot of things that come into play here. ENY SECTION NVIS ANTENNA TEST DAY 4/27/19 10 am to 2 pm, 730-830pm ANCHOR STATION INFO Rensselaer County ARES-RACES, K2REN portable in North Greenbush, NY 3. Less coax is required. Again, this is based on a feed point height of around 40 feet, inverted V configuration, normal soil conditions and no large nearby structures. ca2 fm fm dipole reflector. Since there is no cross-checking of logs for our mW or 160M sprints, the results are now final as of the submission deadline of 2400Z Sunday June 21. I will update you on any significant results I come up with for your records. Doublet Multi band dipole This antenna is a dipole, each leg approximately 60 ft long (overall length ~ 120ft), fed with open wire feeder (ladder line). As already mentioned it is fed at the 1/3 point. 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. The 160 leg is 56″ long and made of 14 gauge insulated wire. Current type 4:1 (200:50 Ohms) BALUN is another product designed for OCF antennas (Off Center Fed) also known as Windom antenna. In fact the only difficult part of an OCF dipole is the balun and I will be explaining how the balun works and also how you can make your own. It needs no tuner on 40m, 20m and 10m. The antenna was created for the 40 meter band and above. It's different from its antennas. 1 Antenna Description 5 1. I measured 75 -j236 at 3. A simple dipole targets 73. But stillness in the air, at the height of summer, means midges and plenty of them. 160m Loop Antenna for TX. EAntenna products online from ML&S Martin Lynch & Sons For full functionality of this site it is necessary to enable JavaScript. Measure a length anywhere from 1 foot to 6 feet depending on where you want the resonant portion of the antenna to be in the band. Re: Question for Wayne about your OCF Dipole Most HF antennas for 160M, 80M and 40M, based on average height above ground, have a feed Z less than 50 ohms at resonance. If this is a Standard Double Bazooka or Shorty Double Bazooka this procedure must be performed on each side of the antenna. Desiring a multiple band wire antenna and not wanting to gather all of the piece parts. 80 Meter Rotatable Dipole If you look closely at the picture above you will see a wire dipole hanging from the tower. At these frequencies the distance between the antenna and the ground may be only a wavelength or two in many instances. 15m —I use the 40m Inverted Vee for this band. The other weekend Don, VE3MNE, and I built an 80m OCF dipole to replace my current 80m-40m-20m fan dipole. height AGL Usable NVIS service occurs from 6 to 24 feet above ground with energy directed upward. I have an OCF dipole that works very well on 6,10,20, and 40. The Wire Size can range from 16 AWG to 12 AWG. Great point for HAM antennas, Delta loops, dipoles, qrp antennas, half squares, hop up your hustler, wire antennas, baluns and other ham radio antennas. The 160 leg is 56″ long and made of 14 gauge insulated wire. Operating a Buckmaster OCF. Special Topics 1. His tower is on a bluff and has an unobstructed view for miles in most directions. The Villages Amateur Radio Club 2015 Antenna Guide for The Villages Rain Gutter Dipole D A Shack C C F F D D C C C D D D height vs WL Each person can decide. Dipole packages consist of two end insulators, one center insulator with an SO-239 and eye bolt on it, and the proper amount of wire needed. The Western HF-10 is a 67 feet long dipole/doublet. A capacitor across the coax adapts the antenna impedance to the coax. They have a disclaimer, to where they suggest using a 4:1 at that height for a 160 meter band OCF dipole: If you are building a 160m OCF dipole and it will be above 60-70 feet, the 4:1 balun (Model 4114 or 4115) has shown to provide a better match. Desiring a multiple band wire antenna and not wanting to gather all of the piece parts. The RadioWavz DX (OCF) Windom is ideal for those of you who do not use a tower and beam. 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. It is an off centre fed dipole, with 10 feet of vertical radiator. Compact Multi-Band Rotatable Dipole Antenna Array Dr. I’ve since been able to buy a stash of 15mm wide clear acrylic pieces in 50mm, 100mm,. For more information, see the Dipole section. 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. These are basically similar but vary in small details. 160M Is a Tough Band • Wavelength makes antennas more difficult -Quarter-wave vertical is 130 Ft -Half-wave dipole is 260 Ft, and it's "low" at only 130 ft -Verticals need radials or a counterpoise, and they work best if they're fairly large. • Baseband processing can synthesize RHC and LHC from a pair of linearly polarized receive antennas. 35-36 A new trap design, using only RG-58 and PVC pipe, yields better space efficiency than conventional coaxial traps. Wideband Dipole for Receiving 16 24. The antenna is designed to be fed with 50 or 75 Ohm Coax Cable of most any length with a Balun. It's also ideal for those who want a high performance antenna with world class DX coverage. hf multiband. 2:1 or better and once I had the OCF up, adding the fan with such short lengths was not much trouble. Loaded dipole on 160m, trapped as a full size 80m dipole. 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 used this to build mine but you can plug in ant freq. Dipole resonance is lower in frequency (dipole too long). Search Results for Antennas. Then I ran. Spiderbeam 160m Vertical Model 160-18-4WTH 2 160-18-4WTH Manual, Ver. MFJ 259B antenna analyzer 2 Homebrew interfaces for RTTY and PC Control. • With good zenith radiation pattern. 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. You only need to type in the numbers in the Cyan boxes. The OCF dipole is a compromise design HF antenna which allows operation on several bands without using an antenna matching unit (ATU). 100 watts into the 75M dipole with 1 watt coming out of the 160M dipole means -20db of isolation. The Short Dipole Antenna. I hung it in an Inverted V config with the apex hanging at approximately 70 feet and the long end (180ft) running to the south and the short end (90ft) running to the north. 00 160-10 Meter W7FG True Ladder Line Open Wire Fed Dipole 240' Dipole 50' Feedline $128. My question; if I make a dipole for 160 meter @ full length, is 253 feet or there abouts. hi i am looking at mounting a dipole the lenght of my house, the whole dipole will be 4 meters above the tin roof will this be a problem, i hope someone may have an answer for me, im looking at the ocf dipole. fullwave dipole when driven at the center will display a typical ½ wave dipole pattern being directional broadside with null off the ends. 7 MHz) and 10M (28. All three bands have remarkably low native SWR, close to 1. how you plan to operate with it. My ham club suggested a 102 feet ZEP antenna for me (center fed) with a ladder line 450 ohm. a horizontal dipole at the same height. For Limited Space / Lanai Use. The so-called "OCF windom" is also a misnomer, for the same reasons. Features include: Heavy duty stainless 1/4 inch center threaded, cemented with lock nut eyebolt supports the off center enclosure for years of trouble free service. One test I did which should impress you is with another ham located 10 miles from me. 3%) dipole fed with 300 ohm ladder line (100 to 120') and coupled by a Elecraft BL-2 balun (switched 1:1 or 4:1) to 9" of RG-58x directly to the 4170. ocf dipole with ladder line. With an antenna tuner, you can operate 12, 15, 17, 30 & 60m bands with ease, where most. how you plan to operate with it. For measurements, and it is shaped like an X. When determining how long to make each leg of a Dipole antenna, dividing the frequency in MHz into 468 will give the overall length. Re: Question for Wayne about your OCF Dipole Most HF antennas for 160M, 80M and 40M, based on average height above ground, have a feed Z less than 50 ohms at resonance. A dipole is basically a length of conductor (wire) split into two portions and signal is taken off at the split. 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. ) 160m Inverted L and 80m vertical wire antennas on a common feedpoint, with a semi-crappy ground/radial system, feed with mini 8 coax 2. A Simple Dipole with SWR Meter 6. 5 kW PEP balun. Here is how I managed to get pretty decent results with a homemade antenna. From a distance it looks the same as an OCF dipole. 15m —I use the 40m Inverted Vee for this band. 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. HORIZONTAL LOOP ANTENNA CONSTRUCTION. But of course, like all the others, the feed impedance of each dipole in a fan dipole is different on each band. 9 dB for 10 ft between 40 Ft and 130 Ft 3. You get an amazing (up to) 11. About a year ago I moved to a larger city and now have a back yard space restriction and I'm struggling with antenna height due to the limited number of trees I have in the back yard. Dipole length in meters: 143 / frequency in MHz. A tuner may be required for 160. W1/Chaplin, CT. UV insulated stranded wire. Old XYL's Tales. 40m Linear-Loaded Dipole. Top DX performing Windom design antenna. The antenna is a short, base-loaded dipole. With an antenna tuner, you can operate 12, 15, 17, 30 & 60m bands with ease, where most. It has a nominal 3 dB gain over an isotropic source and is directional, tending to favor signals broadside to the wire. Off Center Fed (OCF) Dipole Antennas. Spiderbeam 160m Vertical Model 160-18-4WTH 2 160-18-4WTH Manual, Ver. This is particularly true at our fairly low 40 foot test height. So what can we do?. Like many people, I'd like to have one simple cheap antenna that handles 1500 watts, has a low SWR, and radiates efficiently on all primary HF bands. So for 80m and up, you have one leg that is 45 feet long, and another leg that is 90 feet long. 17m —Dipole at 40 feet. The RadioWavz DX (OCF) Windom is ideal for those of you who do not use a tower and beam. I spent a few hours of time modeling OCF dipole or two-wire feed line Windom antennas. ocf dipole with ladder line. The antenna was created for the 40 meter band and above. Antenna height vs impedance : It is very apparent that this ocf antenna doesn't follow the standard dipole input impedance vs height relationship. Ready built. The first thing I did was put up the 244 ft dipole without the LC circuit at the center. At this height, the dipole will not produce a pattern that looks anywhere near the figure 8 pattern that a dipole in free space produces. The dipole is a very simple antenna to construct and understand and will give you the highest value in cost effectiveness. Even an inverted L antenna can be large. You only need to type in the numbers in the Cyan boxes. That is the overall length of a standard dipole. Made to last. OCF to hit the 160m band. Online and downloadable Dipole, Inverted V and Ground Plane Calculators. Then I ran. My rig consists of ICOM 7300 and a 1500 W automatic antenna tuner (MJF). For 30 years I used a 6m dipole, now I have a Yagi. For an 80-10 meter OCF dipole antenna, start with a total length of 135. One combination that fits nicely is 3/4" copper pipe with 3/4" CPVC fittings (not to be confused with 3/4" PVC fittings which will be too large). Right Angle Marconi Antenna 17 26. Four Square Dipoles Array. SWR will be high. The RadioWavz DX (OCF) Windom is ideal for those of you who do not use a tower and beam. the dipole on 20m, to the 50ohm's of your coax, will not happen if you stick the balun/choke in the feedpoint of the antenna like you would on a normal dipole antenna. To optimize the antenna for a frequency RANGE, do the calculations twice, once for the low end of the range and once for the high end; then average the two and plan to adjust the VSWR on both ends of the range as needed. ("Bus") Healy, NJ2L Assistant Technical Editor ipole antennas have been widely used since the early days of radio. The OCF is a Fan Dipole with a 1/2 wave 160M element and a 1/2 wave 80M element 45 degrees offset as in the photo of it at the top of this page. Figure 20 If you design a coupler to feed an impedance of 2450 ohms (7:1 turns ratio), then the expected SWR for a vertical monopole operated against ground is shown below (fig. We brushed it off and made it better! Extensive modeling on the computer then building it, and testing it for days has resulted in what we believe to be the finest "correctly" designed OCF ever made. I worked my lower back while winding but I'm confident the helical wind itself met my exacting standards. This is because the dipole impedance at resonance is close to 72 Ohms, which is much closer to 75 Ohms, as opposed to 50 Ohms. Its impedance at resonance was 53ω. Feed point impedance is high and requires a 4-1 balun. Experimental Chem Phys, an insider’s scoop 4. with their antenna at 1/4 wave high running 100watts who is radiating around 60 watts at 16 deg and the gap gets larger as the height difference increases. The biggest and best ham radio classifieds on the web! Buy, sell, trade HF and VHF equipment, towers, antennas, rotators and more!. The picture on the right above shows an OCF Dipole with 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. One of the easiest antennas to build is a traditional half-wave dipole. However it uses only a single wire feedline. The antenna is designed to be fed with 50 or 75 Ohm Coax Cable of most any length with a Balun. I planned on AM broadcast interference so I calibrated my network analyzer through a broadcast filter. 80-10 Meter W7FG True Ladder Line Open Wire Fed Dipole 125' Dipole 100' Feedline $138. Minus 15-20db is probably the minimum goal to shoot for, since this is the figure that begins to change the pattern of a good figure eight dipole at a decent height above ground. Measure dipole SWR at design frequency. Using EZNEC, the design of an OCF dipole allows many variations in overall antenna length, height and feed point to achieve the desired result. Wideband Dipole for Receiving 16 24. (The thread was entitled “galvanised steel wire”, but the model was clearly labelled steel. Thanks for your response to my e-mails, I really appreciate it. Add as much as you can, at least till the ends are within 15-20 feet from the ground. 3' long) has a maximum gain of about 7. One combination that fits nicely is 3/4" copper pipe with 3/4" CPVC fittings (not to be confused with 3/4" PVC fittings which will be too large). FOR HORIZONTAL ANTENNAS, HEIGHT = MIGHT!! The antenna comes including 12m coax which despite the low weight (only 185g) shows only very modest losses (< 1dB on 40m, < 2dB on 10m). A commercial antenna system, the Buckmaster 7-band OCF Dipole, exploits this property. The Worked All Neighbours Award. Dipole height above ground. Operating a center-fed dipole over the entire 80m-band turns out to be particularly challenging. I have had up a 14 ft ( 4. ) My suggestion would be to read up a little on those two kinds of wire antennas and then edit your question to specify which one you are talking about and what exactly you are looking to find out. 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. com Free Ham Radio Classified Ads from QTH. Go with a winner and break away from the pack. The dipole is a very simple antenna to construct and understand and will give you the highest value in cost effectiveness. Seems like a pretty simple setup. That was suitable for the transmitters of the time where the wire could be tapped onto the output coil. However, any OCF dipole easily outperforms afore-. height versus take off angle This factor is one of the most important one for DXers although many are not aware of this. 5m at the ends. 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. What effect does the height of connection to the tower have on the tuning, and efficiency? What difference would placement of the loading coil make? I started with my OCF Dipole model, and removed the source generator from the feed point, so it becomes a passive element, like the others that I included in the model (tower, satellite antennas. 6 MHz and you arrive at an overall length of 130'. Dipole Antenna Length. An inverted-L seems to be an extremely popular antenna for 160m, and from the reading I’ve seen it’s doable here. An antenna’s gain is so fundamental to its evaluation, that we have written several tutorials on the subject in our educational section. 3 Material Description 6 2. SWR Plot 80% Feedpoint OCF Dipole or Windom. The reactance or imaginary part of the impedance of a dipole is roughly equal to: As an example, assume that the radius is 0. But height is very limited above 70 feet. all with no problem. I will not be building it, since it has about 1. The ½-wave vertical dipole brings in a great many signals that cannot be heard on the big horizontal dipole, and is considered a complete success. As already mentioned it is fed at the 1/3 point. Not all locations will allow 160m tune ability, but worth a try. I decided to make a trapped 80-160 meter vertical dipole with the feed point at 11 meters. Understanding And Building The OCF Dipole by Ron Bertrand. Same dimensions and specs as the original J-Pole but with a screw connector in the middle for easy transport and storage. Unlike the Challenger, the Voyager employs a capacity hat with circular ring to reduce the physical height to 45 ft. This is what it was designed for. I have an OCF dipole that works very well on 6,10,20, and 40. You only need to type in the numbers in the Cyan boxes. We shall see how many choose to either use a 4:1 or 6:1 balun for an OCF dipole. But there is room for improvement for the RX antennas on 40-160m. This antenna would be good for local and short distance communications, but not optimal for DX, due to the high takeoff angle and ground absorption. Current type 4:1 (200:50 Ohms) BALUN is another product designed for OCF antennas (Off Center Fed) also known as Windom antenna. It can be fine tuned for lowest SWR just like a dipole antenna can. The OCF Dipole antenna is very simple. 2 4ghz dipole antenna construction, 160m dipole, uhf 2m vertical dipole antenna, mobile whip antenna dipole, 40m rotatable dipole with fishing pole, 10 meter dipole antenna diagrams, bowtie dipole hf in horizontal plane, rotatable dipole antenna, 160 metre sleeve dipole, bowtie dipole hf in horizontal plane. ), gain of 0dBd and a power rating of 1200W SSB PEP. The 220 ft W8JI multi-band dipole is based on the design guidelines presented in this reference on page 7. half wave dipole antenna calculator. Buckmaster World wide DX, multi-band, no tuner required, Off-Center-Fed (OCF) Dipole Antennas. The 3 additional feet of wire will be used to fine-tune the OCF after you install it. 160-Meter Dipole Height. Engineered for maximum performance with a 14 Gage wire to our coaxial mono band double bazookas of RG11. This calculator is designed to give the total length of a particular dipole (inverted Vees) antenna, or one side of it, for the frequency chosen. this mono band antenna will get you on 160m in just 35-45ft in height. A dipole that is ½ λ high has a characteristic feed impedance of 75 ohms. The OCF dipole is a compromise design HF antenna which allows operation on several bands without using an antenna matching unit (ATU). But height is very limited above 70 feet. I purchased the W2AU 4:1 balun from a local ham outlet. Who are you and why are you here? 2. Frequency, height above ground, etc, etc, that determine antenna current. thanks in advance _____. Antennae for the Low Bands. Probably one of the easiest ways to construct a multi-band wire an-tenna is by using an OCF (off-center-fed) design. It works fair and would like to improve it. The dipole antenna is said by many to be the perfect antenna for a specific frequency. Although this design has been around for a long time, it is only gaining popularity now due to the recent improvement in high power antenna tuners. One of the easiest antennas to build is a traditional half-wave dipole. The first online Dipole and Inverted V calculator on the page below has been around for many years and is designed as a simple "shortcut" so you will not have to do the math using the standard formulas for designing a horizontal dipole or inverted V dipole. The 160m antenna was pretty much the same as used during recent CQ-WW CW Contests. We have used an antenna electrically equivalent to this for over 7 years with outstanding results. Covers all bands, 160-10 Meters with antenna tuner. " This is essentially a dipole cut for the lowest frequency of interest and fed with 450 ohm ladder line. Wire Antenna Design Lengths. dipole at the top using some nylon cord. Buy EAntenna 160OCF3 OCF WINDOM 160m 3kW - R2010025 EAntenna online at £137. One test I did which should impress you is with another ham located 10 miles from me. 15 MHz (about 67. 40m Linear-Loaded Dipole. Hi Walt, I don't know if you know or not, but the Carolina Windom is designed for the vertical section to radiate so it has a radiation pattern which is a combination of a dipole and a vertical. I want to use 50 ohm coax for feed or since I have a lot of it, maybe 75 ohm coax. I quickly had to forget about the 80m and 160m bands due to the length of a half wave dipole (40 meters and 80 meters respectively) and a distinct lack of loft space. A simple dipole antenna can be used for improved FM broadcast signals. Here is a simple multi-band dipole that uses the Off Centre Fed design. 5:1 on 6, 10, 20, 40 & 80m bands and can be operated without an antenna tuner. Now we can see why a Beverage is usually not used for transmitting. The depth estimated for the generator site of the 100m component shows a logarithmic dependence on test frequency whereas no similar behaviour could be observed for the 160m component. One test I did which should impress you is with another ham located 10 miles from me. Dipole Impedance One other factor should be discussed - the antenna feed point impedance. Covers all bands, 160-10 Meters with antenna tuner. I worked my lower back while winding but I'm confident the helical wind itself met my exacting standards. I found it much easier and more efficient to add a fan dipole below it for 12,15. The center of each Tee should be joined to the end of each of the dipole main elements. 40m (W8KSE & W6OQI) produced only intermittent, faint traces on the waterfall. The FT-891 has a small footprint so there is no internal tuner. Like many people, I'd like to have one simple cheap antenna that handles 1500 watts, has a low SWR, and radiates efficiently on all primary HF bands. It all depends on of available room you have to install this antenna. AI4JI's Off-Center Fed Dipole Antenna System This antenna has become quite popular, as the performance is exceptional across the Amateur HF bands. 26 meters for 1. Showing 1–16 of 17 results PORTABLE DIPOLE. The antenna dipole for the 160m band with frequency range from 1840kHz to 2000kHz with overal lenght of 80 meters (~ 262ft) (arms length: 2x 40m/ 2x ~131ft. Very often, on this site there has been referred to the different take-off angles from different types of antennas and their heights. Half-Wave Dipole for 11 Meters (by 56FL114, Pete) A Simple and Certainly Working Antenna Solution. 2% relative bandwidth the 80m-band (3. The antenna was created for the 40 meter band and above. OCF-8010E-3K OCF antenna (Windom) This is OCF Dipole antenna also known as Windom antenna fed at 19% of one end(19/81% ratio). Bedford used an 80m dipole up 30 feet for most tests, and occasionally a terminated, bottom-fed 125. This antenna is unlike most compact antennas with elements running parallel to one another and in close proximity making the elements are tightly coupled, while the completed antenna uses less real estate, there is a great deal of interaction between adjacent elements. Inverted-Vee Antenna 10 15. However it uses only a single wire feedline. > This is a simple Two Wire OCF Dipole Antenna using a > 6:1 Matching Transformer with a Coax Cable feed-in-line. The ultra lightweight matching unit not only matches the coax to the antenna, it also provides excellent choking resistance to suppress common mode current. I couldn’t test in on 160m yet, because my own rig (IC-730) doesn’t work on that band, but the measurements with the MiniVNA show a acceptable SWR between 1800 and 2000 kHz. 26 meters for 1. I have even used it on 160m, but it is very inefficient there. 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. The Western HF-10 is a 67 feet long dipole/doublet. I am not sure if the same would. end to end 14awg. The measurements for the double-dipole off-center-fed dipole system were made at the Laboratory as part of a study of broadband HF wire antennas. The wire-length on this 40m version is actually about 12m per leg. In addition, there are usually house rules and condo bylaws. - 160/80/40 meter band - trapped dipole - 2007. 95 (kit) Shorty 4080K2A - $149. SINGLE BAND DIPOLE 265ft. The K9LA 160m/80m Antenna Carl Luetzelschwab K9LA When my wife Vicky AE9YL and our two sons moved back North (from the Dallas/Ft Worth area) in late 1988 with a job change, one of the requisites of the house was for it to. Sandpiper AT Ltd. 80-40-20 M dipole 80 40 20 Meter Dipole Array By KJ4EX October 2008 Recently I have installed three of these systems, all untuned, requiring the use of a tuner, but capable of operating on 80 through 6 meters. A rule of thumb is (fig»): If you want to experiment then takes account of these data. Also, designs that did better on 80 m, lack 15 m. I supported it from the center of a small tree in my back yard at a height of about 18 feet. Filter GB Dipole 12m Available €33. I have a question for the community. Linearly Loaded Tee Antenna 17 27. 3' long) has a maximum gain of about 7. 160m DX purists will no doubt argue that I am wasting my time with this sort of 'cloud-warmer' antenna. Very good point, I've played with a few low dipoles in the 20 to 30ft height range on 160m and never got any good performance. 5 dBi peak gain on higher bands. This is because the dipole impedance at resonance is close to 72 Ohms, which is much closer to 75 Ohms, as opposed to 50 Ohms. Here's a photo taken from the back of my lot looking toward the house -- note the two antennas that terminate on the PVC vent pipe.