Off center dipole calculator. I briefly considered patenting my design.

Off center dipole calculator 8, 23. Ready to Hang Off Center Fed Dipole Antenna The 40 Meter to 6 Meter off center fed antenna is capable of operation on the 40 Meter, 20 Meter, 10 Meter, and 6 Meter ham bands. 5: Loaded dipole calculators: Ref. For a conventional antenna I would normally split this wire in half and place a feed point in the center. Compared to a single-band resonant dipole with equal length legs, the OCF Dipole offers the advantage of HF Multi-Band operation at the "cost" of slightly to somewhat elevated SWR. We were able to get the feed point up to the 50-foot point (15. The antenna calculator above uses this formula as a starting point to calculate wire lengths for the dipole. Ref. The rods are connected to a wire also called a feeder at the end closest to the center of the antenna. It's a dipole fed off center with a 4:1 current balun at the offset feedpoint. The only differences are three: 1. The title of the main category is Dipole and it deals mainly with Dipole antennas plans. What frequency will you be operating on? Frequency: MHz. With all things equal, radio, power, coax, direction, height, etc. Jun 5, 2021 · The most widely used formula to calculate the approximate overall length of wire required for a dipole is: 468 / frequency (MHz) = length of wire in feet. The impedance repeats every wavelength, so for example if you're interested in the impedance at 2. The antenna shown covers 80, 40, 20 and 10 meters. Hello Operators. 36. Oct 23, 2011 · Here is a spreadsheet I designed in Microsoft Excel for calculating the first cut and the final cut (after testing) of a 1/2 wave dipole, whether center-fed, classic off-center-fed, Windom, or New Carolina Windom. This type of antenna is designed for one principal amateur HF band, usually 80 meters or 40 meters, but typically displays VSWR minima on at least two higher bands, and can therefore be a good multi-band antenna. At this position, the feedpoint impedance should be about 200 ohms. Possibilities I have thought about are: a) feed with coax with a 4/1 balun at the feedpoint. 25m from the center, the current magnitude is 3A, flowing in the opposite direction. Resonant ½ wave dipoles when center fed will repeata resonant and resistive impedance at odd multiples of the fundamental. That is: 468 / Frequency Mhz will give you the overall length of the antenna. To make it even easier you can calculate the lengths of wire required to construct a 1/2 wave dipole using this page. 24 meters high). Their popularity is simply explained because a center-fed dipole operates on its fundamental frequency (f0) and at 3f0, 5f0, 7f0 etc , whereas an OFCD operates on its fundamental (f0) and at 2f0, 4f0, 8f0. 15 MHz (about 67. Jun 1, 2020 · However, on the second harmonic (40 meters for an 80-meter dipole), the impedance is several thousand ohms. The antenna is fed about 87 feet in from one end of the antenna. RARS - The Raleigh Amateur Radio Society Sales/Tech: 760-747-3343, Shipping Inquiry: 760-214-1760 Oct 22, 2011 · What is the best way to hang an off-center-fed dipole or windom antenna as an inverted-V? Should you hang the feedpoint at the apex, or hang the center of the antenna at the apex? From an electrical standpoint the best way is to hang the center at the apex. 2012 Ro’s (M0RZF) experiments and measurements using VNA concludes that the K1POO OCFD benefits from use of a choke balun. Our Hy Power 160-meter off center fed antenna is made with the same material as our 80-meter off center fed antenna. First, determine the frequency (f) in MHz. Figure 3: Xfmr 421c. However…. Dipole. Aluminum/copper tubing construction: You will need to check the fit of the tubing with the T connector and the caps while you are at the store. 4, & 27 MHz if fed Array Solutions 2611 N Belt Line Road Suite #109 Sunnyvale, TX 75182 Phone (214) 954-7140 Fax (214) 954-7142 Email sales@arraysolutions. Resources listed under OCF Antenna category belongs to Antennas main collection, and get reviewed and rated by amateur radio operators. n n n 4R T1 R T1: F 40-43 n = 6 t rifila tu ns 1 . Hall, "Off-center loaded dipole antennas", QST Sept 1974, 28-34. All you need is 2 pieces of wire 3 insulators and a suitable feed line. 160-10m, 80-10m or 40-10 meters depending on your available space. Claims include: Off-Center Fed Vertical Dipole design means no radials, 90% efficient or better across 80m – 10m OFF CENTRE FED WINDOM (4) End-Fed Wire Antenna 9:1 Non Resonant (4) 10M (32) Dipole Calculator; Dipole Calculator. The Center-Loaded Off-Center-Fed Dipole (CL-OCFD) was. com Dipole Antenna Calculator. The larger the wire, the wider the bandwidth. The antenna shown covers 80, 40, 20 and 10 meters with 15 meters and WARC bands only available with an antenna tuner and should be limited to less than 500 watts due to elevated SWR. The ARRL Antenna Book; Off-Center Loaded Dipole Antennas, QST magazine, September, 1974; Coil-Shortened Dipole Antenna Calculator Jan 6, 2018 · The Off Center Fed dipole, will always cause a balanced feedline to radiate because the currents in the line at any instant are not equal. Off Center Fed Dipole. I have, in good faith, given my best efforts to provide a calculator that will save ham operators time in setting up their antennas. The Center-Loaded Off-Center-Fed Dipole (CL-OCFD) was invented and first described by yours truly, Serge Y. However, I chose not to do so as a way to give back to this wonderful hobby Apr 17, 2023 · Ted Edwards (W3TB) gives a detailed presentation of the properties of a multi-band off-center fed dipole antenna. When bent into an L-form it has an impedance around 40 Ohms or about 1. Aug 5, 2016 · Ref. Although thousands of hams use and love these multi-band antennas, some people, including a few well-known antenna experts, view the OCF as a common mode current (CMC) generator or even an outdoor dummy load. It is complete, cut, tuned, and ready to hang. Feb 20, 2021 · The off-center-fed dipole (OCFD) is a very popular and easily constructed antenna for HF operation over a wide range of frequencies. I'm going to look at the OCFD because it is relatively simple to construct, yet gets quite decent performance. A good match at resonance. Suspension Hole. v1. This manual will show four versions of the Off Center Fed dipole that can be made from this kit. exe)" by Alexander Stirling (VE3KSK) Ref. If you raise the center you need to raise the ends by the same amount, the angle is too steep and the SWR always goes up. Whereas a Dipole is a half-wavelength long radiator, fed in the Center of two equal length legs of the antenna, the Off-Center-Fed Dipole (which I sometimes 'falsely' call a WINDOM) is a Dipole whose feedpoint is at a point removed from the center of the antenna - but not at its end. 5C: "Loaded dipole calculator (. The method appears to be based on an equation in J. At home I have a 40M dipole up 35 feet. But we’ll look at the off-center fed antenna, as it has the capability of working on two About the Buckmaster OCF Dipole Antennas Buckmaster OCF Dipole Antennas work multiple bands and are made from the best quality materials. References. HamCall DVD/USB/Download HamCall. Jul 7, 2020 · The OCF or Off Center Fed Dipole antenna is much like a conventional dipole antenna in that the formula you use to calculate the length of it is the same. 64 and . A dipole will present a low feedpoint impedance when each leg is close to an odd multiple of 1/4 wavelength. Hall, "The Search for a Simple, Broadband 80-Meter Dipole," QST, Apr 1983, pp 22-27. dipole with The half-wave dipole is very simple to construct. The Matching Transformer matches the impedance of the Off-Center Fed Dipole (OCFD) antenna to the Coaxial Cable. Highest Desired Band: Frequency for An OCF at its fundamental frequency performs similarly to a center-fed dipole of the same length. It is rated to take 2 KW. Apr 2, 2005 · I want to build an off-center fed dipole for 80 meters and up. 0], via Wikimedia CommonsA folded dipole with equal-sized conductors has 4x the impedance of an ordinary dipole. The antenna described is only 68 feet long Oct 2, 2016 · The rationale for the design is that it is a short dipole, not requiring radials, and feed point offset downwards by 30% as an optimal value for performance (driven by often unsound assessments of coax loss). Dec 15, 2015 · The common choice of the center of a half-wave dipole is usually selected because it's close enough to 50Ω coax that losses are acceptable without any additional matching. Super convenient and quick – great for contest operation! Choose 500, 1500 or 5000 watts PEP power levels. 2 wavelengths, it will work well at any height between 30 and 90 ft. That is where the current is at a maximum on the lowest resonant frequency. The upshot is there may be Jan 18, 2020 · This Off Center Fed Dipole is set up for 80m. One concern with making a multiband OCF dipole is achieving reasonable impedance on all amateur bands. The original javascript was created by Jack Ponton and can be seen here. Hall, “Off-center loaded dipole antennas”, QST Sept 1974, 28-34. OCF Dipole Figure 1 C AR11159_1 Drawn by VK3BR Figure 1: OCF dipole. An article in the September 2019 QST described a variation on the classic OCF dipole antenna for 80-10 meters. In free space the center-fed half-wave antenna has an input impedance that is a close match to 200 ohm so the center isolator contains a 4:1 Balun to convert the 200 ohms %PDF-1. The drawing below is a diagram of a lumped-constant loaded dipole antenna that is intended to fit in available space, rather than requiring a full 1/2 wavelength, at a specified frequency. 6 dBi at 70' up, with an elevation angle of maximum radiation of 27 degrees above the flat, uncluttered terrain assumed by NEC programs. Inverted Vee. It is fed off-center, typically at the 1/3 point, instead of at the center like a traditional dipole antenna. It is recommended to cut the wire a little bit longer than calculated and then trim it to the length that provides you with the best OCFD antenna designer. The K5HH Antenna Calculators are for demonstration purposes only and may not reflect actual numbers for your equipment. B. 5 MHz and 24. 2, 19. In the field I have horizontal dipoles, end fed verticals but usually I’m using an off center fed vertical half wave. Keep reading this article to learn: What is a dipole antenna, and why does its length matter ; The formula for the length of a dipole antenna (calculate the length from frequency and wavelength); An OCF at its fundamental frequency performs similarly to a center-fed dipole of the same length. Dec 17, 2010 · The OCF-3K80 is an off-center fed multi-band dipole. The measurements below are for building a simple Dipole Antenna. As seen on his page, the original formula seems to come from an article by J. I briefly considered patenting my design. One reason for that is because a dipole can be fed a reasonable amount off center before the SWR increases too much. 3' long) has a maximum gain of about 7. It's OK to mix and match dimensions. As I have said, before, I was able to get an off-center-fed sloping dipole antenna erected a week ago, Friday (12 March 2021) with the help of my Son, KF7IBY, Robert. 80/40/20/10m). 1. Frank VK3BFC Sep 6, 2012 · Being that I was building a 10 thru 80 antenna ( if you remember it was a 40) I had to change the length of wire also. A dipole antenna is a simple antenna design consisting of two conductive elements, typically wires or rods, that are symmetrically aligned and fed with a radio frequency signal. Monday January 2025 Phone +44 (0) 7753225261; Apr 17, 2021 · If you click on his call sign, it will take you to his QRZ biography page where he has attached a presentation on the so-called “end-fed halfwave” antenna…so-called, well, because he argues it does not exist. 5 m ecw Trifilar 4: 1B alun - 42 Figure 2 C AR11159_2 Drawn by VK3BR Figure 2: Xfmr 421a. The basic antenna that we used was a 3. 5 wavelengths. Also a good match. 35 inches. This could be 50 ohm types such as RG58, RG8X, RG8, RG213, or 75 ohm type such as RG11, RG59, RG6 or even 75 ohm twin lead. 5-MHz AWG #14 copper wire element. A standard horizontal dipole is fed at a position other than the centre. J. 5: loaded dipole calculators: Ref. Review Summary For : Buckmaster 7 Band, 3KW, OCF Dipole Antenna; Reviews: 92 MSRP: 324. 1, presented here primariliy for mathematics buffs or those having access to electronic computers. 0 Mrk, K3PPP, needs a little clarifaction on how he should trim his OCF-dipole, and he would like to know how Dave came to his answerDave will answer both o Jul 30, 2022 · With our dipole length calculator, you will find the optimal size of a half-wave antenna for any given frequency in a few seconds. 5A: "On-line short Off-Center-Loaded dipole calculator by Martin Meserve (K7MEM) Ref. operation, while choking off unwanted currents on the transmission line. The formula can also be used to adjust the overall length to cover more or fewer bands and the resulting overall length. The dipole antenna is probably the easiest to make. The equations behind this web page are really just a geometric solution, so, this page can be used with any type of wire antenna, dipole, trap-dipole, folded-dipole, etc. Holding true to the original Windom formulas, I used a ratio of 37. May 1, 2021 · Center-loaded, off-center-fed dipole (CL-OCFD) with feed at 16. 3. n1 n2 4R R T1, T2: FT1 40- 3 n1, n2 = 12 b if la rtu ns . In most cases, no antenna tuner is needed and switching bands is as easy as changing the band on the radio. 2% for the longest side after determining the half wave length at the lowest operating frequency…. Next, use the formula L = 468 / f to calculate the length of the antenna (L) in feet. Store / Antenna Products / CUBE Impedance Dipole Antenna. A dipole antenna consists of two conductive rods or metals of equal lengths separated by an insulator. 5B: "Shortened dipole calculator (. I am grateful to Craig Pennington, Mar 31, 2016 · Building A Homebrewed Off-Center Fed Dipole Scanner Antenna. The antenna is designed to be fed with 50 or 75 Ohm Coax Cable of most any length with a Balun. Standard install is 30' in center, 10' on ends. Oct 25, 2015 · There are a few ways to build multi-band HF antennas. net Gold Membership Buckmaster OCF Dipole Antennas Antenna Support Rope Line-Grips Harken Stainless Steel Pulleys RF Chokes CQ Magazine Archives World Prefix, WAS, and Great Circle Maps Custom Great Circle Maps HamCall Mousepads Custom Name Badges Amateur Radio Operator Certificates Antenna Wire Screw-on Cable/Wire Clamps Stringliner Reel with 270 feet of operation, while choking off unwanted currents on the transmission line. 5 Mhz , while an OCFD cut for many: a length of wire with a tuner, a dipole (or inverted-vee) with traps, a vertical with traps, an 80m dipole with a tuner for 40m, a 40m dipole with a tuner for 80m, and probably a couple others. 5A: On-line short Off-Center-Loaded dipole calculator by Martin Meserve (K7MEM) Ref. Sep 25, 2021 · Ref. Notes. 5 m ecw Guane lla 4: 1Ba un - 2 c Figure 3 n1 n2 T1 T2 C A Off Center Fed Dipole Antenna, 80-6 Meters (9 bands-including 15 meters), 500/1. The End Fed OCF uses the same dimensions but the wire section The basic formula for determining the wire length of a center fed, 1/2 wave wire dipole or inverted Vee antenna (30 mhz or less) is 468/freq-in-Mhz for feet and inches or 143/freq-in-Mhz for meters . Use 75 or 50 ohm cable to feed the centre of the dipole. 5C: Loaded dipole calculator (. For 160 M dipole --That means: 1. Jul 30, 2024 · Two high-located, obstruction-free points to plant the antenna — the dipole's length is the most crucial feature to consider; and. Instead of dividing the length in half, multiply it by . The normal Windom is described as having a 1/3 length leg, and a 2/3 length leg. Wire Connectors. Stroobandt,ON4AA, intheyear2006. 4 , 9 MHz, 12. 5MHz, would also operate 10. 4%, total length = 67. Note: the GUI of this calculator shows inductance as "mH" instead of "μH"! Catenary dipole; Zig-Zag dipole; Meander dipole; Other Topics. 4 %äüöß 2 0 obj > stream xœÕ]Y‹,;r~ï_Ñφj§¤\*áPÐ[ ømf øÁøi¼€™kð¼Ü¿oI!)¾ -™Õ§ l ôéÎÊTJ¡X¾ØTÓ‹yþýé ž'ÿo5öyÛíóßþýéŸÿáù¿ÓÕéùoÿùôöóÉØùÅ ¾˜—íùç¿=ÿãÝûû þÇ¿ü˜Ìíb Löæ ¸ÛÅü˜æøs‰—×øû ^§=þÿ ?y»]– Ó{xìãvõ?¦Ïé ?‰w™éf&ý̧1·rƒ½]Ö0Œýa ·˜™>ˆ“0køu The authors work at the Communications Research Centre, Shirleys Bay, Ontario. 5B: Shortened dipole calculator (. 8% for one side and 62. Elevated Radials; Dipole Sag; Dipole Slope; Articles of Interest; Home: A straight, center-fed dipole has an impedance around 70 Ohms or about 1. The OCF-3K80 is complete with a 4 to 1 Balun. 1/2 wave Dipole Calculator. They have no external connectors and a permanently sealed white PVC weatherproof center enclosure containing the potted autotransformer acting as 6:1 voltage balun. exe)" by Al Legary (VE3SQB). All about the OCFD antenna; what is good about them, what is bad about them, and how to build them to eliminate the bad points. Rather, he has proposed “extremely off-center fed” (EOCF) as a more appropriate nomenclature for this particular antenna design. exe) by Al Legary (VE3SQB). Design an Off-Center-Fed Dipole (OCFD) antenna, in either flat-top or inverted-Vee form, using a single main support. On a half wavelength piece of wire, there is only o The PAL-OCF4010 covers 40-30-20-17-15-12-10 and 6 meters in a length of 66 feet. 5KW/5KW PEP rated - FREE shipping in USA. For example, the Palomar Engineers 4010 OCF is a very popular antenna and consists of an off center fed dipole with sides of 55 feet and 11 feet and it will work all bands from 40-6 meters. The Wire Size can range from 16 AWG to 12 AWG. Other bands will require a tuner. 4 SWR50. 95; Description: No tuner, multi-band, off-center fed(OCF), 135 ft. Vertical. It will work well on the 80, 40, 20, 17, 12, and 10-meter ham bands with no need for tuning. 5 wavelengths (off the chart) it won't be far off from the impedance at 1. It is much better to balanced the dipole by putting the feedpoint in the center, and employing well constructed balanced line and a balanced link coupled matching network to transition to unbalanced modern 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. A dipole antenna is a straight electrical conductor measuring 1/2 wavelength from end to end and connected at the center to a radio-frequency (RF) feed line. The web page does all calculations in US/Imperial measurements and converts on input and output, as necessary. 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). Feeding a dipole off the center tames the wild impedance swings as we go up the bands with the caveat that we use only the even harmonics … 40, 20, 15, and 10 meters for an antenna cut for 80 meters. Keep the antenna legs at a 120-degree to 180-degree angle as viewed from the side. May 17, 2022 · If the parasitic element isn't centered to the dipole's center, then the EM field distortion will be not be symmetric to the dipole, thus the distorted EM field will unbalance the dipole. A center-fed half-wavelength wire antenna cut for 7. com Off-Center Loaded Dipole Antennas QST magazine, September, 1974 "The complete set of equations is expressed in the mathematical relationship below as Eq. It is one of the simplest types of antennas and has a 360-degree radiation pattern. This CalcTown calculator calculates the length of a dipole antenna. 3 SWR50. invented andfirstdescribedbyyourstruly,SergeY. 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. Let's take a look at the OCF40 from Chameleon Antenna. Fan Dipole. Dipole Examples Horizontal Half Wave, OCF DJ0IP Image 62’ – 40 meters only-offset for 50Ω 66’ – 75/20 meters (traps) Palomar OCF Read it off this chart: Interferometrist [CC BY-SA 4. Stroobandt, ON4AA, in the year 2006. The antenna can be mounted as a dipole or inverted vee. I will be using an LDG AT100Pro II automatic tuner. These include multiple resonant dipole arrays, trapped dipoles, resonant loops and the off-center fed dipole, OCFD. Wikipedia gives the math to calculate the impedance at an arbitrary point for a half-wave dipole: THE GENERAL IDEA: When the original Windom antenna was developed around 1923, the idea was to take a half wavelength of wire, and feed it at a point along the wire that would have [near] equal impedance on all amateur bands at the time (i. The results are conveniently displayed in inches, centimeters, feet and meters. The inverted Vee antenna legs will be longer by 2 - 6% from those of the horizontal antenna depending on the angle. The Wire Connectors enable connection of the Antenna Wires to the Matching Transformer. . He might consider using an Un-Un, because the ODF dipole does not have equal radiators of equal length. Uses hybrid balun containing wide band 4:1 transformer + 1:1 common mode feed line choke to keep all The negative sign indicates the current's direction has reversed compared to the center of the dipole. If you want a different frequency, calculate the length of a standard half wave dipole. Note: the GUI of this calculator shows inductance as "mH" instead of "μH"! An improvement on the Windom is the Off-Centre-Fed Dipole or just OCF. The legs of the antenna drape down to about 16 feet at their ends. Some years ago I made a conventional link dipole for 40m and 80m, and discovered that, with one link open and one shorted, it resonated close to 60m. It also acts as the center insulator and support. 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. This means that a centre fed dipole cut for 3. See full list on hamradiosecrets. exe) by Alexander Stirling (VE3KSK) Ref. However, ultimate responsibility for the proper use of your equipment lies with you. Note: the GUI of this calculator shows inductance as "mH" instead of "μH"! The half-wave dipole is very simple to construct. 5 MHz , 17. 8 , 5. Apr 21, 2021 · The Off-Center Fed dipole (OCF)–also called a Windom by many–has received mixed reviews among amateur radio operators. 6, 16. The shield of a coax feed line to an off-center fed dipole usually (always?) can't be centered in the dipole's EM field, thus is an off-center parasitic element. Nov 15, 2018 · What I found was this little gem: a description of the vertical, off-center-fed, half-wave dipole antenna that he uses for portable operations: I use a variety of antenna systems. This is commonly used to operate 15m using a 40m dipole, or 10m using the 7th harmonic resonance with an 80m dipole. Basically, one leg is 64% of the half wave and the other is 36%. A 40-meter off-center-fed dipole (OCFD) is a versatile antenna for portable operation or space-constrained fixed stations because it is a manageable length and can cover 40, 20, 15, 10, and 6 meters with low SWRs. Off-Centre-Fed Dipole OCF’s are a descendant of the Windom. I am grateful to Craig Pennington, Apr 14, 2023 · An off center fed dipole antenna might be the ultimate portable lightweight hf antenna available today. As long as the physical length is longer than 0. Description: The Dipole Calculator is a tool used for calculating various parameters of a dipole antenna. b) use coax just to get outside the shack and place a 4/1 balun there and go the Sep 4, 2022 · I put up an OCF Dipole antenna in a portable situation while traveling and working in Poland #OCFdipole #WireAntenna #hamradio This antenna can be purchased Off Center Fed (OCF) antennas are very convenient as they will allow multiple bands of operation with a simple wire antenna which is fed off center. e. The formula can also be used Dec 11, 2024 · the original fan dipole; trap dipoles; off-center or end feeding; changing the effective dipole length; harmonic resonances. The resource has been on our site since Wednesday Sep 19 2012, and it has been viewed 946 times. DX Engineering Multi-Band Off Center Fed Dipole Antenna Kits (OCF) take advantage of the practice of feeding two different length wire dipole legs with a 4:1 Balun. Aug 14, 2024 · The following steps outline how to calculate the length of an Efhw Antenna using the formula: L = 468 / f. , - should I expect an 80-10m End-Fed wire to send / receive different than a 80-10m Off Center Fed Dipole? The primary difference is feed point, end-fed @ 20 feet sloping upwards to 30 feet, then back down to 20 feet and the OCFD at fed at the middle around 30 feet and sloping Here is a formula and calculator for creating a loaded (shortened) quarter wave vertical or balanced dipole. Center-Loaded Off-Center-Fed Dipole Antenna, or CL-OCFD for short. Aug 6, 2024 · Off-center-Fed dipole Antennas category is a curation of 20 web resources on , HF antenna for hams with limited space, The Off-Center-Fed Dipole Antenna, The Six Meter OCF Sleeve Dipole Vertical. If you would rather calculate the length of a full-size vertical antenna, see The Quarter-Wave Vertical Antenna Calculator. I also am fortunate to have some nice tall trees… or no tuning. With the OCF dipole, one might not employ the same 1:1 choke balun he might employ with a center-fed dipole. Nov 30, 2024 · an unconventional link dipole. For example, if you raise the center the 50' you need to raise the ends by the same amount Dipole Antenna Length Calculator. The objective being to find an impedance on the antenna that can provide a reasonably good match to the transmitter across multiple Feb 1, 2018 · FAQ: Off-Center Fed Dipole vs Standard Center Fed Dipole What is an Off-Center Fed Dipole? An Off-Center Fed Dipole (OCFD) is a type of antenna used in radio communication that has one end of the dipole longer than the other. The overall length of the 160-meter off center fed antenna is 268 feet. C. If you use it for a … Continue reading → Here are some typical OCF dipoles that are successful designs 160-6 meter Double Off Center Fed antenna layout (using a double tuned stub for better 20/40 meter performance) Here is the 160-6 meter SWR graph using 200 feet of RG213 feed line and an average height above ground of 35 feet: Palomar Engineers PAL-OCF1606 […] 2001-March; Zack Lau (W1VT), in his article “Making the Off-Center Fed Dipoles Work”, after modelling the OCFD concludes that a line isolator ( choke ) is required for optimum operation of the antenna. Mar 24, 2021 · This design exercise resulted in a new kind of antenna which I dubbed Center-Loaded Off-Center-Fed Dipole Antenna, or CL-OCFD for short. Dipole Antenna Calculator. The upshot is there may be. Daily applications: Dipole antennas, owing to their simplicity and efficiency, have found a broad range of applications in daily life. It’s a dipole fed off center with a 4:1 balun at the offset feed point. Sales/Tech: 760-747-3343, Shipping Inquiry: 760-214-1760 discussed aspects of the behavior of off-center-fed (OCF) antennas used for multi-band HF service. Hence, at 0. Place a 1:1 Balun on the Antenna end of the Feedline. 2. The OCF160 covers the following ham bands. " The Off Center Fed dipole (OCF) is made up of two different lengths of antenna wire (dipole legs) for operation on multiple bands. Of course — our simple dipole calculator to assess the length of the device. afe azxqc hxnb dekgxne dxmnhok bdykwf lupb wfza pvklh ocz