Ocf dipole inverted v. 44 SWR in free space) Gain: 1.
Ocf dipole inverted v. This offset gives the antenna the multi band capability.
Ocf dipole inverted v The Red graph line rises. 6 -j2. In contrast, the studies on bent-end and V-dipoles are symmetrical optimized for full length before bending into the resonant form. Relative to the 30 meter pattern, the peak radiation angle is lower, 70 , which is a better take-off angle of 20 for DX. this antenna is more of a flat top than an inverted V. 8. While any angle other than 180 degrees would technically make a vee, it is often assumed that the Apr 28, 2024 · Figure 2 displays the pattern of an inverted V with the apex at a height of 63 feet (almost 1/4 wavelength at 3. Fig. n1 n2 4R R T1, T2: FT1 40- 3 n1, n2 = 12 b if la rtu ns . All of my HF antennas are being used with my main transceiver; so, I decided to install a 40m Dipole. Yes, the OCF is pricey, but well worth the money. Apr 23, 2019 · With an antenna analyzer and the information in Figure 2 and Figure 3, you can impirically tune a Tall (or Wide) L-Antenna as closely to 50 Ohms as possible as follows: Calculate 1/2 wave wire length: 150/MHz = meters (Example at 6 meters: 150/52. Bending into a V-shape is one of the most used possibilities to get on the air with good results. The RADIO WORKS™ has antenna arsenal. 5 m ecw Trifilar 4: 1B alun - 42 Figure 2 C AR11159_2 Drawn by VK3BR Figure 2: Xfmr 421a. If what you are tying both of your ropes to are both fixed objects Jan 5, 2020 · I recently got the Ham It Up Upconverter for my Nooelec SDR. 2015 Fig 1. The 450 Ohm ladder line is fastened along the soffit board, runs down the back of a plastic drain pipe and then along a wall until it meets the 50 Ohm coax - not straight or vertical or perpendicular to the antenna in any way. Update: 10-2-2016 Put up an OCF 7 in a similar inverted V, even higher than the ZS6BKW. 68 ohms in free space) SWR 50: 1. The purpose of this communication is to provide a simple understanding of the behavior of a Mar 9, 2019 · However, about 2/3 of the total inverted-V signal is lost to ground when compared to a straight EFHW wire at 40 feet; from 6. A lower resonant frequency for the same length of wire as the dipole. The first one I put up 3 weeks ago st 35 foot center inverted V. For example, I have an fan dipole setup like an inverted V and I can reach Europe (east), Asia (west), Canadia (north) and South America (uh, south) from Colorado Mar 9, 2019 · However, about 2/3 of the total inverted-V signal is lost to ground when compared to a straight EFHW wire at 40 feet; from 6. 95 dBi when sloped. ) It must be made of durable, high quality, weather worthy components. For this study the long arm is fixed vertically K5SPP 2014-07-24; The Best First Antenna, Hands Down; Worked for me! My first antenna was a 20 meter dipole cut to the middle of the General band out of 18 gauge insulated wire I picked up at Lowes. Worked Europe, Asia, South Africa, West Coast, Canada, South America mostly on 17M and 20M. With my main transceiver, I am able to hear traffic on the 40m Jun 24, 2014 · Fantastic antenna! Raised it up about 50 feet into an inverted V in a tree and getting great reception and QSOs across 40 and 20 meters so far. The feeder from the house to the antenna is DXE400MAX (LMR400 equivalent) coax. Superior to the Windom. This is Part Apr 20, 2003 · Dipole Impedance One other factor should be discussed, the antenna feed point impedance. Jan 10, 2025 · The PAL-OCF2006 covers 20-17-15-12-10 and 6 meters in a length of 32 feet. com Ver 1. Online and downloadable Dipole, Inverted V and Ground Plane Calculators. Apr 21, 2019 · To answer this question a generalized OCF antenna model was developed where where any length of wire could be bent at any point and each arm could be set at any angle. Looking at the Blue line you will notice that the Gain goes down (as always) when a dipole is bent. "Factory" meaning purchased, and with a lot of other customers using this same setup without problem. The antenna can be installed in an inverted V configuration keeping in mind that this design changes the feedpoint impedance and will tune differently. In most cases, no antenna tuner is needed and switching bands is as easy as changing the band on the radio. Each of these deployments change the characteristics of a well-designed OCF Dipole that has a high-Q (h igh-Q = narrower bandwidth = greater efficiency). Upon checking the antenna with my antenna analyzer I found the SWR across 3 days ago · Off Center Fed Dipole Notes. Intentionally striving for a radiating feedline achieves very little, while accepting a feedline that radiates harms little, if adequately isolated from equipment in the shack. Antennas/OCF; The title of the main category is OCF and it deals mainly with Off-center-Fed dipole Antennas. Installation is not optimal, meaning it's not at the altitude nor exact inverted V dimensions that the book calls for. 5 MHz or lower). The following chart shows the variations in impedance as the dipole is lowered from . Figure 3: Xfmr 421c. FT8 and similar digital modes are a different animal and if that's all the OP wants to operate this is good news. The inverted Vee antenna legs will be longer by 2 - 6% from those of the horizontal antenna depending on the angle. Discussion in 'Amateur Radio Equipment Reviews' started by N7TML, Sep 27, 2007 available--even those that are 30 years or more old--will show you the different characteristics of a flat-top and Inverted-V dipole for the variables including the height above ground -vs Jun 29, 2020 · NEC4. A dual band, 40/80 meter, inverted V using coils is a popular way to cover the low HF bands while conserving space. A Simple 4 - Band Wire Antenna. 5 to 54 mhz may need tuner on some bands. Let’s assume you want to focus on 80m and 40m CW. 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: Aug 13, 2019 · There are two main ways to install the antenna: as a straight Off Center Fed Dipole and as an inverted V. We should really call them Extreme Off Centre Fed Dipoles. For portable operations we have a 12 m high Spiderbeam glass fiber mast, which limits the maximum height of our antenna. Since you only need to put up one pole, do something to get it a little higher. Please Click for Pages at Kilo Three Triple R – K3RRR. 3 dBi versus 1. 840MHz. May 13, 2018 · Like the previous post by Peter Parker (VK3YE), Dave takes a 40 meter dipole or inverted V and adds more bands by means of loading coils, carefully chosen element lengths, and optimal height to give us multiband capabilities without the use of Locked OCF dipole Leonard N4LJT. Configured as a slight inverted V at 50 apex and 30 ends. So that seems to suggest these two possible options. Uses hybrid balun containing wide band 4:1 transformer + 1:1 May 13, 2012 · It can be hung in a flat top or inverted V configuration. The effects of symmetry are discussed in the OCF (Off-Center-Feed) pages. Note that the gain of the antenna at high angles is the same as a dipole. Before going any further, I should mention here that the OCFD is sometimes falsely referred to as a "windom" antenna. Same with the OCF. Nov 15, 2024 · Being a beginner with EZNEC, I suspect it is me doing something wrong! Below I attach from EZNEC 1) the dipole configuration 2) the source set-up 3) the "fan inverted V" configuration and a diagram showing the antenna. ) of the length of a theoretical straight dipole, 150/MHz = meters. I put up the combination at 35 ft as in inverted V. n n n 4R T1 R T1: F 40-43 n = 6 t rifila tu ns 1 . 80M OCF Windom Di-Pole I've had this antenna for several weeks now and along with a MAT Tuner mAT-y200 for my Yaesu 991A and I can tune across all HF bands. I have it set up in an inverted V approx. $379. Dec 16, 2020 · The inverted V dipole antenna is a simple, reasonably efficient HF antenna for those operating in restricted spaces. This manual will show four versions of the Off Center Fed dipole that can be made from this kit. Gain from the lobes is about two-thirds of that of a straight antenna, 6 dBi compared to 8. After installing the OCF, check the Manufacturers of off-center-fed dipole antennas choose an offset feedpoint where the theoretical impedance is approximately 300 ohms on the antenna's *fundamental* frequency of resonance. This is the 1500 watt model. Order 7 Aug 29, 2022 · Off the ends the inverted V performs far better, since the nulls are now directed down into the ground, and at least some of the energy a dipole was sending straight up is being sent toward a horizon. In Figure 2, look at 80 (a downward slope of 10 ). 92 dBi. 4) Between 6 to 20 feet (s ee NVIS information below regarding these mounting heights). But you can always drive out to a far away place, set up an antenna and get on the air Nov 9, 2013 · the inverted vee starts as a horizontal half wavelength dipole, then the ends are slowly brought towards the ground. 00; Description: A well-constructed 7 band off-center fed dipole, designed for 75/80, 40, 20, 17, 12, 10 and 6 meters. The center connection is an old Carolina Windom 4:1 current balun fed with RG-8X. Aug 1, 2023 · Tried an OCF dipole for about a month, now I have a 20m dipole on a 40ft mast inverted V. When a half-wave or full-wave dipole is bent: the gain goes down; the resonant length gets shorter; the frequency goes higher; the impedance decreases. 99 I'm asking 140. 1 www. Higher is not always better. " Erecting at least 30 feet above ground is recommended. Apr 22, 2019 · The slight asymmetry introduced is small versus the great convenience of using a single telescoping end-section for tuning. Feb 20, 2023 · I ordered a OCF dipole for 40 meters, but if I put it up, instead of a true inverted V, I was wondering if I can run this in a horizontal V orientation at about a 60-80 degree angle between the legs? So it would be a flat top configuration, but almost like Dec 12, 2017 · I bought the 7 band 3K OCF Dipole to give me the bands my KIO Hex Beam did not handle. Save your inverted V G5RV or Windom for 80m where they seem to work quite well with high-angle radiation. Jan 7, 2025 · An inverted V half-wave dipole doesn’t do this, so if you must have an inverted V for 20m, use a half-wave dipole, not a G5RV or OCF (Windom). One of these properties is the required height above ground, which increases with the wavelength. Installation of the CHA OCF40 as a horizontal dipole, especially if mounted lower than normal (around 10 – 15 feet high), will enhance Near Vertical Incidence Skywave (NVIS) performance. and with a little tuning with a ATU Jan 1, 2008 · inverted V-dipole. For good DX performance, the apex of an 80-meter drooping-dipole antenna should be as high as possible above ground (at least 15 meters [50 feet]), because the antenna's vertical radiation angle Apr 21, 2019 · Typically the most common is the inverted-V, ends bent down and inverted-L forms. Works 3. Here are some typical OCF dipoles that are successful designs. Sat Jul 21, 2018 by DropTableFoxes. Wind now has a 3/4 inch poly pipe Apr 21, 2019 · We start with a tuned Standard Dipole of #14 wire mounted horizontally and fed in the center at 1/2 wavelength elevation. EZNEC models of dipoles from the standard formula, fed directly with 50 ohm coax (blue line) or series matched (purple line). It works pretty well and I have made contacts with Canada, Puerto Rico, Italy, Croatia, and Serbia on 40M and 20M. 44 SWR in free space) Gain: 1. Apr 24, 2020 · brought this on was a question about the OCF antenna, and I did a lot of work to understand how this particular antenna works. Even if I had the space to put up an HF antenna where I live, the noise floor being a constant S9+20 would make actually using it quite difficult. Be sure the ends of your inverted-V are at least eight feet above ground so they aren’t a danger to humans and pets. This off-center fed dipole antenna is ruggedly built with 14 awg stranded copper wire, and is weather-resistant for outdoor use in permanent installations--- external hardware is stainless steel. 35-40 Feet above the ground. 8040. Thanks! I have installed this OCF dipole at 25 feet and haven’t had this many contacts on so many bands in my 50 years of hamming ! use and the one I keep in the air all the time mostly for 160m and some 80m the 270' 3 kw 6-160m one mounted in an Inverted V @ 55' with the ends @ 25'. Sep 13, 2013 · KF9F Revives an OCF Dual Feed Multiband Dipole This multiband 160 thru 10 Meter antenna design was adapted using the dual feedline technique from and old 73 Magazine Article published in 1984 by W4HDX** Note that Resource Details You will find this resource in just one category on our links directory. 5 = 2. It’s an 80-10m Jun 10, 2022 · (Apologies for slight buzz on audio - now fixed) This time I show you how to model a simple Flat-Top Dipole then we convert it to an Inverted V. Because of the slope, the oval vertical radiation dome is tilted 10 away from vertical. Inverted V antenna for 40 and 80 metres. At very low angles the Jun 13, 2021 · End Fed Workshop Topics Short overview of antenna feed points Dipole, OCF, Zepp, Loop overview Popular End Fed Antenna s How to choose an End Fed Antenna that fits your needs Secrets of Non-Resonant End Fed Antennas Typical Configurations that work all the time Feed Line Chokes, Counterpoises and Coax Noise Filters Solving End Fed Antenna RFI An EFHW is really an OCF dipole, it's just fed very close to the end, and the coax makes up the short end. The change is not significant until around 60 when it drops below 7 dBi. 3 days ago · Off Center Fed Dipole Antenna, 80-6 Meters (9 bands-including 15 meters), 500/1. The antenna worked well but had extremely high reflected power on Usually works best as an "inverted-V. This study proceeds stepwise form 0. I bought the 7 band 3K OCF Dipole to give me the bands my KIO Hex Beam did not handle. This will result in good NVIS patterns, shown in Figures 18 and 19, at Oct 7, 2013 · 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). I know that's frequently suggested as an alternative to an exposed antenna, with attic placement. I am curious though how exactly the pulleys come into play without me having to get upon a ladder leaned against a tree. It does not include 30m or 15m in the 7 bands, although with a manly tuner you can get out on those bands. If necessary, the legs may be bent to fit Today I built and put up a OCF inverted-v dipole using with a 133 foot total length of #14 insulated THNN with the short leg cut to 44 feet. 05. Dec 19, 2022 · Once we move in I'll be putting the Buckmaster 7 Band OCF Dipole back into service - and I'll be adding a Hexbeam to it. to 140 ft. 13 dBi (which equals 0. The radiation pattern is crap on higher bands and it requires a tuner and 4:1 balun (a PITA if you ask me). The OCF dipole will perform well in a variety of configurations and comes to you FULLY- ASSEMBLED. Only when the length is three or more half-wavelengths can bending increase gain as you transition into gull-wing, half-rhombic V and rhombic antennas. 39 (versus 1. 90% of the reports are 5-9. It can be hung in a flat top or inverted V configuration. 2nd OCF antenna purchased hete! This is my second 7 band OCF antenna purchased here. A more omni-directional radiation pattern than that of a dipole. Aug 22, 2024 · Palomar Eng OCf Dipole Model # PAL-OCF8010. Contact And Location Info 80m Antenna On A Postage Stamp Hi my name is Richard VK2KRM from Australia. I am looking to put up a Inverted "V" dipole for 160m 1. Super convenient and quick – great for contest operation! Choose 500, 1500 or 5000 watts PEP power levels. If the antenna is for 80m and above it should work well for NVIS on 80, 60 and 40m. If I did a dipole (CF or OCF) I'd do an inverted V, but packing a light 30ft mast inside of a 20" backpack is much more problematic. • Either Horizontal or Inverted-V • Can use OCF – Off center feed • Horizontal wire angle can change but should not exceed 90° • Wire elevation can change but vertical components do not contribute to NVIS pattern Apr 23, 2019 · The starting Length is calculated as a Ratio (0. Oct 18, 2021 · That means the ends will be angled in an inverted V configuration, so what does that do to our radiation pattern? Here is a plot of our 20M dipole, now in a V configuration with the two ends each sloping at 30 degrees: 20 Meter Dipole V at 42 feet with wires sloping down at 30 degrees. Both work very well for what they do. Regardless, it works very, very well. 5KW/5KW PEP rated Unlike Buckmaster OCF antennas (at twice the price, and no WARC bands, (flat top, inverted V, inverted L, etc. Any help/ pictures appreciated. OCF 8 bands 160-6 HF Windom antenna; This dipole can hang flat or in an inverted V configuration. 79 ohms (versus 71. As a straight antenna you tie ropes to both ends of the dipole and raise it as high as is possible. Aug 30, 2021 · The performance of a dipole is highest when it is not bent. 57 dBi at 15 degrees elevation above horizontal (versus 2. Put up the next day as an inverted v at 60 feet. Aug 18, 2021 · The inverted-V form is common where there is only one high place, often a pole, to hang a long wire antenna. 9, 0. I had to do something to improve 80. The resource has been on our site since Tuesday Jun 9 2009, and it has been viewed 1858 times. SWR is under 2:1 on all of 20m and 40m. Resources listed under OCF Antenna category belongs to Antennas main collection, and get reviewed and rated by amateur radio operators. Jun 30, 2021 · You will be making an inverted V dipole on its side. Feb 9, 2007 · The whole installation is in the form of a sloping inverted-V with each end probably no more than about 12ft (4m) above ground level. A standard dipole generates a horizontal ratiation pattern in the shape of a figure 8, with maximum radiation broadside to the antenna. • Average Height to not exceed 40 ft. 1 wavelength. The exception being if the legs are several quarter wavelengths long like if you were operating a half wave dipole for 80m on 20m or 10m. It requires about 102 feet of space and should be at least 31-32 feet high or higher. It should be mounted as an inverted-V. To what I have read over the years. 5 MHz, at least when we place the antenna 60' above ground and build it from AWG #12 copper wire. WB2JSY Jan 19, 2011 · Off-centre-fed dipole (OCF dipole) The antenna can be installed as a horizontal dipole or an inverted V. Buckmaster OCF Dipole. I ordered one and the Maxcon isolator. It is rated to take 2 KW. Yet another characteristic is the radiation pattern. 19 dBi of gain and take off angle at 25 degrees. A couple friends were running the OCF-3K80 with great results on multiple bands. 5 -j1. 06 dBi at 40 feet horizontal drops to 0. Never-the-less, the more complicated meander form is a size reduction alternative to consider if you do not to deal with want loading coils or traps. A dipole's impedance varies according to its height above the ground. After installing the OCF, check the resonant frequency on or lowest SWR for 80 The advantages to an inverted-V configuration of an OCF dipole are pretty much the same as making a standard dipole into an inverted V. The Inverted-Vee tends to be more omni-directional and radiate equally in all directions. As the end of the antenna approaches the ground, the % Length at I have the 6-Band 68-foot model OCF Dipole (didn't have the room available for the 135-foot model). Quiet on all bands, flat across from 80-10, with a bump to 1:2. I have the supplies I need to put up a dipole. 6 MHz and you arrive at an overall length of 130'. 3/66. By using the optimization function, the antenna model program iteratively converges on the Height that gives the best match for the target frequency. ) and direction, feed line length and type, geographic location and soil condition, May 9, 2011 · Actually it applies to ALL frequencies. If the OP is a phone guy then the list of 160m FT8 contacts doesn't mean much as he could never achieve anything remotely close on phone. B. It should be in the low portion of the 80 meter band (e. Apr 25, 2024 · Construction details of my dual band inverted V dipole antenna for 40m and 80m by Andrew Westcott, callsign M0WAN. I have DXCC on all but 160, 80 and 30, and 250+ grids and 20 countries on 6m with that antenna (at 30', mind you) so it can't be all bad. ; A lower feed point impedance than the horizontal dipole (for feed points at the same height above ground). SWR Feb 20, 2015 · Insulator 1 Insulator 2 There are many versions of the Off-Center-Feed Dipole That said, the OCFD has a important place in your or OCFD being sold. Dec 16, 2008 · An interesting facet of basic NVIS antennas—the dipole, the 1-λ loop, and the inverted-V—is the suggestion that we can improve antenna gain by placing some form of wire structure below it. com Array Solutions Fan Dipoles Manual Thank you and congratulations on your purchase of the Array Solutions, Fan Dipole Antenna Mar 9, 2019 · On 80 meters, with the end of the antenna close to the ground, a six-fold loss in gain stands out6. This offset gives the antenna the multi band capability. 255-λ in 0. Off Center Fed Dipole (OCF) Antenna-Ham Radio Q & A; Dec 16, 2008 · Of all NVIS antennas, the linear dipole is the most basic. Cebik’s 3,4 and Craig LaBarge’s 5 writings in recent years. Had serious problems with the two I've built including RFI and difficult to tune out SWR. Each end can droop up to 30 degrees from horizontal, 180-(2*30) Buckmaster 8 Band 300 Watt OCF Dipole 160, 80, 40, 20, 17, 12, 10 & 6 Meter. If configured as such, the included angle at the apex should exceed 120 degrees. That is, you get more radiation off the ends for a tradeoff of broadside radiation, and you Usually works best as an "inverted-V. Jul 28, 2016 · I have the Buckmaster 7 band OCF dipole, and it performs pretty well. Version 2 of my 40m Ultra-Light OCF dipole has been working for almost one year now. 1 outlines the dipole and the critical properties necessary to examine its performance at possible eights above ground. 5 m ecw Guane lla 4: 1Ba un - 2 c Figure 3 n1 n2 T1 T2 C A Apr 21, 2019 · The Standard Vertical Dipole Characteristics Impedance: 69. The possibilities are numerous, but the most common suggestion is the addition of a single-wire element. A percentage adjustment can be entered below according to the following guidelines: Sep 16, 2021 · Dipole Geometry Options • Total length (both legs) between 100 ft. It will work well on the 80, 40, 20, 17, 12, and 10-meter ham bands with no need for tuning. 857m) A velocity factor depending on metal, wire size and coating helps but is not really needed. Back To Radio Intro > 40m & 80m Antenna. Aug 12, 2021 · I assumed the OP was going to use voice and that will be extremely disappointing with a low dipole on 160. May 13, 2022 · The inverted V antenna shares a lot of the properties from the similar, traditional dipole antenna. 2 comparison of an inverted V, center-fed dipole with a linear center-fed dipole: AUTHOR EDITS: The apex angle in my plots here is mislabeled. 12 dBi down to 2. Performance vs practicality plus other considerations when fitting a dipole in limited space. Inverted V is a handy sorta-omnidirectional antenna. arraysolutions. Mar 10, 2013 · How to build and tune a 40 meter Inverted V wire dipole HF antenna. At 105 the Gain is a full dBi lower and the SWR becomes higher Jul 5, 2015 · Hi, Harold! I’m contemplating running a G5RV or 100 to 120 foot dipole for 80-10 meter operation, possibly OCF, only about 20 feet in the air between trees and alongside my Use DUCT SEAL or Hot Glue to seal the upper end of an inverted “V” dipole or high end of a Sloping line. Highlighted Features. Buckmaster 4 Band 3000 Watt OCF Dipole 40, 20, 10 & 6 Meter. Apr 22, 2019 · Inverted V; Inverted L; Slow-Wave. Above right: The red trace is a G5RV inverted V with the apex at 12m and the ends at three metres. The dipole has a reference angle of 180 degrees, that is, each side of the dipole is inline with the other, making a straight line. A 45-Degree 136. 14 dBi omni-directional in free space) Beam Width: 40 degrees (half-power points, -3 dBi) Apr 21, 2019 · For long-wire dipole antennas, space may be a problem in a yard or attic. Heavy Duty OCF Dipole antenna will give you 7 bands without an external tuner and 2 more the others cannot or don't recommend using an Went to Array Solutions and purchased the 5k OCF dipole. What antennas are available? There are many: a length of wire with a tuner, a dipole (or inverted-vee) with traps, a vertical with traps, an Jul 21, 2018 · Building a Multiband Inverted-V Dipole. In all three of my installations, I ran the dipole north/south in an inverted V configuration. Apr 26, 2014 · Dipole, Inverted V and Ground Plane Antenna Calculators. Compared to the V-antenna or inverted-V, the effects on antenna characteristics of a laterally bent dipole are simpler because the distance to the ground is constant. don't think this is right, Z varies from 73 to 50 as you bring it from a dipole to an inverted VEE, Apr 23, 2019 · A space saving antenna in the form of an upright L has been around the amateur radio world for a long time. 5 wavelength above ground to . Review Summary For : Buckmaster 7 Band, 300W, OCF Dipole Antenna; Reviews: 33 MSRP: 192. References are found back to a QST article in the 60’s 1, the ARRL Antenna Handbook in the 70’s through 90’s 2 and to L. 9 MHz). Sep 5, 2015 · An OCF antenna is similar to a dipole, except that it is not fed at the center but at a point offset from the center. 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. For years I ran a 40 meter dipole at 35 ft and an 80 dipole at 12 ft. Works great. The antenna pretty much met the goal of having a 4-band simple coax-fed dipole that does not require an antenna matchbox. It's a grounded vertical wire connected to a horizontal portion acting as a top hat capacitance. g. The correct value is 120°. Elevated Radials; Dipole Sag; Dipole Slope; In this OCF vertical dipole Gain is less, 1. Unlike Windom’s and OCF Dipoles the G5RV is a very forgiving antenna with the consideration of nearby towers, Trees, fences & other structures. Putting ladder line into the equation removes that single benefit and adds issues of balanced/unbalanced interaction and common mode current issues that could be minimized and/or avoided by simply using the traditional balanced Center fed dipole fed with 5 days ago · 4:1 (OCF Dipole) 49:1 (EFHW) 9:1 (EFRW, etc) 4:1 (OCF Dipole, etc) 1:1 Balun: Connector: BNC Male BNC Female SMA: BNC Male BNC Female: SO-239: BNC Male BNC Female: Max Power: An EFHW antenna radiates Apr 21, 2019 · Along the top of the graph for each angle of bend there is a red graphic representation (looking from above) of the bent dipole. The right arm can be swung up or down at any angle. Oct 21, 2012 · OCF Dipole Figure 1 C AR11159_1 Drawn by VK3BR Figure 1: OCF dipole. One side is 44. Tunes up with my tuner on 160 and 80 meters no problem. Then the antenna develops lobes that tend to align with the direction of the wire itself and becomes more end fire than broadside. 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 Dec 9, 2014 · Construct a multi-band off-center-fed (OCF) dipole covering the 40, 20, 15, and 10 meters amateur radio bands, and possibly the 6 meter band (but that is considered a bonus band, outside the main project objective. For example, an 80 meter dipole cut according to the formula, hung at 80 feet and directly fed with 50 ohm coax will exhibit a very poor “best case” SWR of Oct 8, 2022 · With a completely horizontal dipole, it will make some difference. As seen from the table, an 80 meter antenna at half Aug 22, 2021 · This can provide you with a better match than a standard dipole. A windom antenna is a single-wire-fed antenna which is worked against ground. The center should be 35 – 45 ft up and must have a reasonably solid mounting point to support the Excellent OCF Dipole Time Owned: more than 12 months. We shall evaluate each dipole at heights from 0. It can be used in any of the standard dipole configurations, flat-top, inverted V, sloper, vertical dipole, wire vertical w/counterpoise, Aug 29, 2024 · Buckmaster Off-Center-Fed (OCF) Dipole - Multi-Band Antennas 4-Band does 40, 20, 10 and 6 meters, no tuner required! Legs are 23 and 45 feet 7-Band does 75/80, 40, 20, 17, 12, 10 and 6 meters, no tuner required! Legs are 45 and 90 feet 8-Band does 160, 75/80, 40, 20, 17, 12, 10 and 6 meters, tuner may be required for 160. 5 inches long and the other side is 25 feet long, with a 4:1 current balun in the middle. 7), the sweet spot we are trying to find (exact position of the new feedpoint) is often very narrow. $394. 8, etc. But the orientation of an inverted V tends to make it more omnidirectional. The left arm is fixed. I'm very impressed with the build quality. Buckmaster 7-Band OCF Dipole Antennas are 135 feet (41 meters) long and work on 80, 40, 20, 17, 12, 10, and 6 meters. Unlike Windom and OCF Dipoles, the ZS6BKW / G5RV is a very forgiving antenna when it comes to nearby towers, OCF Windom Dipole Antenna Poly-Stealth Ni4L. If we add only 15 degrees to the slope of each inverted-V leg, Aug 26, 2023 · Putting up an OCF Inverted V Dipole. Upright or inverted, either Sep 13, 2013 · KF9F Revives an OCF Dual Feed Multiband Dipole This multiband 160 thru 10 Meter antenna design was adapted using the dual feedline technique from and old 73 Magazine Article published in 1984 by W4HDX** Note that both ends of Overall installation of the OCF dipole at 34 feet apex in inverted V fashion Sep 25, 2015 · A Truly Broadband, Efficient Low Band Dipole - 2 - W7ZZ and N6RY, c. 0 dBd or zero gain). Terrific results in the first month of use with the antenna up 50ft in an inverted V configuration as recommended Oct 24, 2019 · My first antenna was a Buckmaster OCF dipole, I had a home brewed 10-80 meter antenna with an overall length of 135' hanging in an inverted 'V' configuration at my QTH for the past six years and it functioned flawlessly. In either case the antenna will work better the higher you can put it up. Feb 8, 2021 · I've read about polarizing the dipole as an inverted V shape. 5 ratio to determine the characteristics Jan 10, 2025 · this 7-Band OCF Off Center Fed HF Dipole Antenna 1 KW PEP wire WORKS GREAT on the 7 bands advertised. I Sep 12, 2017 · I'm running an 80m straight (not inverted) OCF dipole 28' off the ground. Pros. CHA OCF40 Page 7 OCF40 as Jan 17, 2021 · Dipoles compared: Horizontal vs Inverted-V vs 'Sloper'. On the other hand, an OCF dipole is an ungrounded dipole antenna fed with twin Apr 21, 2019 · The computer model for this study bends the antenna in the middle by any angle from vertical. I am looking for mostly dx contacts but would like to be able to talk to base stations on sideband that I talk with from time to time with the furthest being about 50 miles from me. Eg. Wire-end coupling to ground tends to reduce the effective height of the inverted-V relative to its effective height when Sep 27, 2007 · Alpha Delta DXCC vs. In consideration 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 Mar 2, 2020 · Review Summary For : Buckmaster 7 Band, 300W, OCF Dipole Antenna; Reviews: 33 MSRP: 192. Nonetheless, all of these models fail to predict the observed impedance mismatch. The retail on this is 199. RULES specific to this month's sprint: None Date and time: Thursday, January 16, 2025, 0130-0330 Z Entry Deadline: All entries must be received before 2400Z on the Sunday following the sprint. We shall start with a 40-meter dipole and then proceed to lower frequencies. The antenna is 143 feet long can be put up as inverted V or Flat top. ) and direction, feed line length and type, geographic location and soil condition, May 15, 2010 · I have used my dipole hung horizontally or in a sloper configuration from about 8 to about 12 foot high but I'm thinking about running it as a inverted V on a painter's pole front about 20 foot tall. Sep 24, 2020 · Just be sure you have two supports, such as trees or poles to hang the dipole. Ends should be 10 feet or more from the ground for proper broadcasting and safety. The study here involves first setting an angle then running the optimizer. If you only have one support, you can droop the ends into an inverted-V configuration, which can also save space. Compare. That antenna buried my first HF antenna the "Cobra Ultralite". All Messages By This Member #1114 looking for feedback on putting up an OCF dipole for 80 to 6 meters. 075-λ up to 0. , 3. The balun / A Stealthy, Rugged, 100 Watt 40 thru 6 Meters Multi-band OCF Dipole for Home, Portable and Base Station Operations Simple, Elegant, High Quality For Less. How to build and tune a 40 meter Inverted V wire dipole HF antenna. ". 4 dBi . Ham-made in USA from quality materials. Oct 18, 2023 · Inverted “V” or as a horizontal dipole. This means, for example, that a junior G5RV will be elevated at most 13 feet higher than the ends of the dipole. I picked up a chassis-mount SO-239 from Radio Shack, and used an old, plastic cutting board from the kitchen for the insulators, and mount for the -239. Sirio SD 27 Dipole CB/10 Meter Base See General Sprint Rules for rules common to every NAQCC sprint. Feb 1, 2024 · OCF 8 bands 160-6 HF Windom antenna. On higher bands the takeoff angle for DX will depend on the height of the wire with roughly 33ft high being desirable as being 1/2 wavelength on 20m and a full wavelength on 10m giving a low takeoff angle on those bands. 6' Inverted-V. By Andrew Westcott: M0WAN. This could easily route a wire about 25' or more up and Dec 17, 2010 · The OCF-3K80 is an off-center fed multi-band dipole. The graphic below compares the elevation pattern gains at 90° azimuth intervals for these two configurations; posted in response to the comment of rclocher3. I have found it to be exceptional in every way and had it orientated North-South, bought a second one and put on my other tower to give East-West and have them setup for NVIS since I also do MARS/SHARES. Well-built product; Has versatile use; High flexibility and resistance to harsh conditions. Jul 13, 2021 · I have a 40M off-center fed dipole hung as an inverted vee about 25’ up in a tree in my backyard with the ends about 8-10’ off the ground attached to my fence. and slopping the legs down at 45º, creating the familiar 75m inverted-V antenna as seen in Figure 17. Feb 3, 2020 · Tim: I am using an OCF Dipole, inverted "V," 40' high at the feed point (give or take), specifically, the Buckmaster OCF. In short, the only reason to use an OCF dipole is to be able to use coax on a single wire multi band dipole without a tuner. Dec 20, 2024 · Even though it is one of the simplest antennas, the drooping dipole (a dipole with drooping ends, popularly referred to as an inverted V) is effective on 80 meters. Legs are 90 and 180 feet Feb 26, 2019 · The doublet that we shall use is 135' long, just long enough to be a resonant dipole at 3. They seem pretty comparable to me in an inverted V on 20m/40m. Sep 9, 2016 · Array Solutions 2611 N Belt Line Road Suite #109 Sunnyvale, TX 75182 Phone (214) 954-7140 Fax (214) 954-7142 Email info@arraysolutions. When the dipole will be installed in an inverted 'V' configuration (rather than straight-horizontal) the formula should be modified to reduce the length . I have a "factory" provided voltage balun and a "factory" provided 600-1000 ohm choke directly below the balun. 2025-01-20 00:00:00 GMT+00:00 left to submit your log Jun 13, 2017 · Figure 16: Cross-Dipole Antenna Pattern at 75m A similar effect can be achieved by raising the apex of the 75m dipole to 50 ft. . Commercial designs are seen in the Buddipole TM 5, MFJ-1790 6 and Mar 23, 2018 · 3) Installing the antenna as an Inverted V. The resonant length is slightly longer! Presumably this because the antenna is closer to ground at one end therefore not quite symetrical to reflected RF. So submit as soon as possible, using our on-line autologger. If you have the room and can make a antenna a to cover 160m that it can work on other harmonics frequencies of the base frequency of 1. I don't want to deal with multiple high points in the trees, but I can get a single high point up there. I get better signal reports and break pileups easier with the EFHW. I purchased the 3 kW version of this Buckmaster 8-band (160, 80/75, 40, 20,17,12,10, 6m) OCF (off-center feed) dipole with the purpose in mind of having a single antenna to cover the lower HF bands (160/80/75/40m). Add To Cart. Who has experience with the inverted V, either in the attic or elsewhere, and what was performance like? Reactions: highwayman1224. Nov 19, 2020 · The antenna is an OCF Dipole (inverted-V) with the center at about 45 feet. 100 watt ICOM 7000 4 days ago · Off Center Fed Dipole Antenna, 80-6 Meters (9 bands-including 15 meters), 500/1. One concern with making a multiband OCF dipole is achieving reasonable impedance on all amateur bands. 9 to 0. Most POTA / SOTA operators will install the CHA . They don’t seem to have much effect on it. Another often seen upright V-form is in the Buddy Pole or the similar MFJ Big Ear portable dipole. In this well-made video, Dave Tadlock (KG0ZZ) shows us Jul 9, 2019 · Straight Sloping Inverted V Inverted L Catenary dipole Zig-Zag dipole Meander dipole Elevated Radials Dipole Sag Dipole Slope Articles of Interest Note:Every half-Wavelength Height adds a figure-8 broadside to any half-wavelength of wire. Oct 24, 2014 · For an 80-10 meter OCF dipole antenna, divide the ½ wavelength standard of 468 by the lowest operating frequency of 3. Will need a tuner to run high power, mostly as a safety device so I can It's Horses for Courses again! AND remember, when we start moving the feedpoint away from the clasical position (33. I've even thought of adding a Buckmaster 8 Band OCF dipole and running it perpendicular to the first so I can give 160M a try. The signal will radiate more from the broadside of the wire. Usually works best as an "inverted-V. " Erecting the center at least 30 feet above ground is recommended. The inverted V results in:. May 1, 2024 · At the fundamental frequency of an OCF antenna, performance is thus at best similar to that of a center-fed 1/2 wavelength dipole and at worst about that of an inverted Vee. An ultra-lightweight 4-Band wire dipole - weighs less than one pound, including 40' of coax. I find the noise floor lower with the dipole but also receive strength suffers a little, but the lower noise floor compensates. Remember, higher is better. Like 30 meters, the radiation pattern develops four lobes each at 45 from the horizontal arm. is 20' elevation sufficient? can it be mounted in an el shape, do not have room for it to be mounted in a straight Mar 9, 2019 · However, about 2/3 of the total inverted-V signal is lost to ground when compared to a straight EFHW wire at 40 feet; from 6. This antenna is brand new and never been out of the package. 160m, 80m, 40m, 20m, 10m etc. It's position is influenced slightly by things like height of the feedpoint and heights of the two ends, angle of the legs (in case of Inverted-V) and type of Aug 8, 2021 · B) hanging the middle (inverted V) about 30ft, and getting both ends about 8ft off the ground. A round reflection dome develops between each half-wavelength. Suggestions for OCF: For a 5 Meander dipole, feed at around the 9th segment from center. Use it on 40, 20, 10 & 6-meter (it even loads on 15) with NO tuner. The first online Dipole and Inverted V calculator on the page below has been around Dec 17, 2008 · The Practical NVIS Inverted-V for 75 and 40 Meters As we found in earlier notes within this series, the inverted-V center-fed dipole requires a greater center height for maximum performance than a level dipole. After installing the OCF, check the resonant frequency on or lowest SWR for 80 meters. 0 on 20M. Video Rating: 4 / 5. The antenna has nice stainless-steel hardware. It is a fine general purpose, probably had more experience with this type antenna efficient, trapless, multiband antenna with a radiation Feb 23, 2019 · I wouldn't do the OCF. Feb 11, 2023 · First: There is an oddity at a slight slope. Starting with our standard vertical dipole with the feed point 1/2 WL above average ground, the study is to increase the V-angle in Mar 15, 2023 · The Off Center Fed dipole (OCF) is made up of two different lengths of antenna wire (dipole legs) for operation on multiple bands. Mar 9, 2019 · On 20 meters, the antenna resonates in four half-waves. Most of the antenna's elevation is only a small fraction of a half-Wavelngth Height so only a slight directional elongation develops. Jul 13, 2020 · One such solution could be an "inverted L" wire antenna: Using a telescopic mast to get the wire up in the air from one balcony, and over to another mast raised from another balcony. Catenary dipole; Zig-Zag dipole; Meander dipole; Other Topics. Second: Following the Red line. Jun 5, 2021 · When each side of a dipole slopes down from the feed point, it is commonly called an inverted V. 01-λ 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 . If you have a decent fan dipole you don't need a tuner either and the pattern is the same for all bands. The antenna can be mounted as a dipole or inverted The basic formula for the half-wave dipole is 468/freq (in MHz), but it can be modified below to your needs. 00. Check Recent Price. I just talked to someone recently who suggested that I have my antenna too high in the air for NVIS, but I have Aug 14, 2023 · I was planning on 10-15ft horizontal for NVIS, and sloped for DX like you said. Most of the radiation is horizontally polarized and divides like a 4-leaf clover with each leaf being diagonal to the line of the wire. wava xqea osoc wwfjse hnse anozm zoqnga axfblh zydhctb taano