2m Dipole

This calculator is designed to give the horizontal length of a particular dipole (including Tees) antenna, or one side of it, for the frequency chosen. Experiments can be performed by constructing a T-type dipole with 4:1 balun. VHF/UHF Quad Antenna - IW5EDI Simone - Ham-Radio VHF/UHF Quad Antenna The information in this article has come from many amateur sources, the most notable was from WA6TEY (sk 1985) Ray Frost, who was a pioneer of VHF Quad designs and one of the best Southern California Transmitter Hunters of the 1980's. Examples would be a "dipole" or vertical, either symmetrically or asymmetrically constructed, where the feed cable leaves the antenna near a high voltage point. The horizontal dipole, however, is most effective when its height above ground is at least 3/8 of a wavelength. uk 01922 414796, for all your radio needs. Study of the Off Centre Fed Dipole Antenna - G8ODE Short Long Feed point The Off Centre Fed Half-wave Dipole The Off-Centre Fed Half-Wave Dipole, more commonly referred to as the OCFD, is very popular because it offers good performance as a multi-band antenna using an antenna matching unit in conjunction with a 4:1 or 6:1 current balun. Typical dipole lengths for the bands from 40m to 6m are given in Table 4. 44 at 145 MHz and Under 2. This "mass defect" effect comes from the forces of "acceleration electric fields" acting to speed up the charged particles. Purchase both the six meter 6M-F magnetic loop and the two meter circular dipole for only $189. "Subject: Plumbers' Dipole Antenna Date: Fri, 13 Sep 2002 13:39:21 -0500. The HexTenna™ Yagi by Alpha Antenna® is a legal limit and full size portable 10-20 meter HF & 2 meter VHF Yagi that is deployable as a UHF/VHF/HF Vertical/Dipole HexTenna™. 0 mHz and ~445. Shop our selection of Alpha Delta wire antennas, including multi-band sloper antennas for limited-space applications and SWL antennas for superior performance through 30 MHz. The brass plate to hold them form an "L" 1-3/4" tall with a 1/2" lip. 25M BOXX TB-2 FM/VHF/UHF Vertical/Dipole antennas tri band. The shape is 11" X 11". For homebrew vertical VHF antennas, coaxial dipoles often play second fiddle to J-poles. This will affect the radiation pattern. A spectrally-selective electromagnetic (EM) absorber is an engineered platform whereby all incident energy is trapped and absorbed at a certain spectral spot, while all other reflection. Delta Fed Dipole Antenna 13 18. Coax cable routed thru cross members, 4ft section of fiberglass mast and soldered to SO-239 round connector. 17 Meter Dipole. But don’t be misled – just because they are easy to make doesn’t mean they don’t work well. Coaxial Folded Dipole Antenna. Small Five-Element Yagi. Adjustable, fixed, side or top mount antenna Offered in a 1/4, 3/8 or 1/2 wave spacing version The 872A-70 has external cabling and a field-adjustable pattern. Joined: Oct 26, 2008 Messages: 408 Likes Received: 21. The diagram above gives the basic format for the antenna, but in reality the antenna will need to be erected between two supports. It works great! It is temporarily mounted at 19ft on 2 sections of Rohn 15G tower that is bracketed to my garage. Remember to cut your antenna wire longer than shown here and then adjust the length to the desired frequency. Click on Calculate and the optimum length for that combination will be displayed in feet and inches. 6 - Slim Jim 2M EZNEC Model Definition and Currents Fig. I like to tinker, so when I finish one project, I go on to another, even if it works well. Length L(meters) = 142. Thanks in advance for your time and. Being the crafty maker type, I wanted to build my own antenna. 2nd 2m antenna is a home brew 1/4 wave sitting on the corner of my desk near the window. 2m Folded Dipole. Cushcraft has a storied history of producing top-notch antennas and antenna accessories. Note the radiation pattern of the antenna in the plot below the VSWR graph. GigaParts - Your trusted source for Amateur Radio, Computers and More!. DIY simple dipole antenna for VHF and UHF bands (2m and 70cm). Vertical Dipole Arrays (VDA's) have been used very successfully by DX-peditions, such as VK6DX (Ducie Island). 0 mHz) Please select Mast Mount Size (THE MAST MOUNT INCLUDED IS BASED ON YOUR SELECTION) Includes: Antenna, Mast Mount Slip Type. 30 Day Money Back Guaranteed! 12-month free replacement warranty for manufacturer's defects! Product Description: Designed to solve the problem of bad FM signal, ANT FM dipole antenna with TV female connector. Homebrew 2M Dipole Antenna When it comes to an antenna on my HT, other than get rid of my factory rubber ducky, I've never played around with it too much. Sources and Links. 5% shorter than a dipole. Here is a 2 meter 144-148 MHz circular folded dipole, capable of 100+ watts, which is a very compact antenna, requiring no ground plane, small foot print and ideal as a “bookshelf” indoor antenna for those who are restricted in their ability to put an antenna outdoors, or who want to remain stealth. Center insulator 3/8 Derlin rod. Quality build and very affordable. 40m Linear-Loaded Dipole I stumbled-upon this antenna design whilst searching for something resonant, but not too lossy for 40m working. The antenna is designed to be fed with 50 or 75 Ohm Coax Cable of most any length with a Balun. Even zip cord such as what is used for lamp cords will perform quite well. Antenna Gain: 3dBi Pattern: Omni. DIY 40m Band 1/2 Wave Dipole Antenna. Parts Catalog: Maximum power is 150 watts Boom is 1" square. The Length of folded dipole * La = 145 / freq ( MHz ) Length of coil * for 75 ohm cable : Lb = La x 0. Vertical Dipole Arrays (VDA's) have been used very successfully by DX-peditions, such as VK6DX (Ducie Island). We are also a 501c(3) public charity. A local friend that I told about this antenna project built it today. Army War College, The United States Military, U. Making it a resonant antenna for all bands from 80m to 6m (except WARC bands). This formula takes into consideration the capacitive "end-effect" from insulators which shortens the physical length requirement for the equivalent electrical length. Discussion in 'Amateur Radio Antennas' started by WR0220, Jun 11, 2009. The antenna is a dipole with resonant frequency of 250 MHz. It requires a balun and works very well. There are times when you may need more gain than the standard J-Pole antenna. M2 Eggbeater Sat Pack. Please see the V3 features pdf. length (L), with several inches added for tuning and for securing to. (Factor of 4 higher*). Mounting bar and pole mounting bracket on request for an extra £8. The SWR is very low across the band. When you use a J-pole configuration, but orient it so that it's horizontal, it's helpful to envision it as a half wave dipole, end fed, with a quarter wave matching section. This is the most common type of dipole antenna. Tuning is carried out in the same way that you would tune a standard 40 meter dipole. I proceeded to make a very heavy dipole from copper pipe, akin to the type used for J-poles. The hot antenna points UP, the ground antenna points Down. 2M Net: 144. 4 x 8 Dipole Driven Element AlAntenna Plate 1 2 Driver Elem to 175 Boom. 5 Ohms ( two 75 ohm coax cables in parallel ) is used to transform the driven element feed point to 50 Ohms. As the Slinky dipole is just a dipole, there is at least one more standard way to tune it: asymmetrically. " It has two antenna pieces which are each half a wavelength long. 0 mHz / 420. 9) q= l r θ ρ l. Typically, the width d of the folded dipole antenna is much smaller than the length L. I still had the coax outside on the roof and the pole which were both used previously for my 2m/70cm co-linear, which has been relocated to the chimney, so once it was built, it was simple enough to put up. Other Side. php 7032 Bytes 08-11-2019 17:10:52 Folded Dipole Calculator. Mount Side close up. Mini QRP Portable Dipole. ost commercial 2-meter repeater antennas with gain fall into two categories: collinear arrays and stacked element arrays, with gains ranging from 3. I decided to go back to the drawing board and starting from scratch, designed an entirely new, much lighter, 2 meter vertical dipole. The magnetic dipole is a microscopic loop of current I and area A with the magnetic field B computed from Biot-Savart's equation, while the electric dipole is a microscopic charge pair of charges +Q and -Q separated by a distance d and the electric field from the charges is computed from Coulomb's law which is inverse square for each charge. A short dipole is a simple wire antenna. 5 Ohm feed-point impedance (if fed as traditional split dipole). Poles and center joint have holes for easy wall attachment. (Factor of 4 higher*). Joined: Oct 26, 2008. Your antenna will look something like this: 18. 95: A-3S: Beam,Triband,3 ele. 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. WBØTGE "Mighty Woof" 2m/440 Dual Band Fan Dipole (DBFD) I call this the "Mighty Woof" antenna. FREQUENCY-A dipole antenna will not only work well on the frequency it is cut for, but also for the multiples of that frequency. WBØTGE's "Mighty Woof" - 2m/440 MHz Dual Band Fan Dipole This article was submitted to HamRadioSchool. It is an ideal project for home construction and is best suited for temporary /P operation hung. • The antenna shall be supported from a single point at its center. This dipole cleared that right up. 468 / 146 ~ 3. 0 design: kg4jjh 11/15/05 tested: kg4jjh kg4jjh scale: 1/4:1 sheet 1 of 4 vertical dipole-4 (bottom) shown horizontally drill 1/8" drain hole drill 1/8" drain hole 9" 8-5/16" 30" 30" 2-1/4" notes 1. Solder the antenna parts together using 90 degree elbows at the corner open ends and mind the gap. USGS Publications Warehouse. 25" outer diameter for easy mounting. Terminated Folded Dipole Antenna System: 10 Meters through 160 Meters commercial-grade performance, heavy duty construction, and top-notch customer service. The Cycloid Dipole antenna: The CP antennas that we are testing are Cycloid Dipoles constructed of 1/2" rigid copper tubing ( See photos , below) with each one being constructed similarly. 2m Lindenblad Parasitic + Vert. One may argue that 560 feet is ridiculous for a 40 meter dipole, but keep in mind that the data can be scaled down to a 10 meter dipole with similar results. I hope that you have any ideas what should I do. I am a brand new ham and your dipole has become my first fixed antenna. That is: use a different variation of turns-count and/or inter-turn spacing in the two dipole legs, to make an Off-Center Fed (OCF) Slinky Dipole. The latter will have sensitivity and selectivity better than average. Off-Center-Fed Dipole, OCFD, Windom, Whereas a Dipole is a half-wavelength long radiator, fed in the Center of two equal length legs, the Off-Center-Fed Dipole (which I prefer to call a WINDOM) is a Dipole whose feedpoint is at a point removed from the center of the antenna. This way, the resonance frequency and feed-point impedance can also be adjusted. The whip ends of the antenna could be adjusted for additional tuning. I dont really use it much except for projects like this because CB bands have went to toilet talk and I really dont want to listen t. This link is listed in our web site directory since Wednesday Aug 29 2007, and till today "2 meter dipole antenna" has been followed for a total of 20747 times. An electric dipole of moment is placed in a uniform external electric field as shown in the diagram. Click & Collect. 2:1 with SWR no higher than 1. Pull the whole piece of outer. 000 megahertz. It shall not employ rope to tether it. The driven element feed point has a impedance of 28 Ohms, so a quater wave transmission line transformer with a characteristic impedance of 37. eSynic UV-5R Walkie Talkie Dual Band VHF/UHF with LED Display 128 Memory Channel with flashing Alarm and Radio Function Supports VOX for Construction Site Hotel Outdoor Adventure with USB Charge Base. Compact and effective 2m/70cm dual band antenna for satellite operation Antenna was designed for SO-50 satellite operation. "Subject: Plumbers' Dipole Antenna Date: Fri, 13 Sep 2002 13:39:21 -0500. The 70 CM band may be limited. The horizontal dipole antenna (fig. 2m Stick Vertical Dipole 3D View: enlarge 110KB, 444x1024 2 2m Stick Vertical Dipole Front View [1 large square = 5 inches] enlarge 25KB, 791x1024 3 2m Stick Vertical Dipole 4nec2 File Includes Summary of Dimensions: enlarge 175KB, 1024x722 4 2m Stick Vertical Dipole Raw Gain = 2. ideal for the FT-817 etc. In radio and telecommunications a dipole antenna or doublet is the simplest and most widely used class of antenna. Made From a TV Satellite Dish. NAGOYA SP 45 BLACK Dual band mobile antenna 2m 70cm PLUS MAG. Working the 2m band SSB. The monopole has a mean value of modulation transmission in the above frequency ranges of 0. 1/2 Al tube. I am a brand new ham and your dipole has become my first fixed antenna. In this case, the dipole is such a system, so it will have lower inertial mass than $2m$, thanks to its negative electrostatic potential energy $-frac{e^2}{d}$. I used 1″ thin-wall PVC pipe, aluminum tape, and RG-8X coax. A small delay may be needed to get a smooth overall picture. 1005 /F(MHz) feet or 306. Make your own 2m band dipole antenna that's easy to make and doesn't cost much. The metric formula is total length (in metres) = 142. 2m / 70cm Vertical Dipole Antenna. the diagram isn't a slice through. 95: A-3S: Beam,Triband,3 ele. 1/2 Al tube. Dipole Configuration Results 6 Meter Dipole. Obviously of shorter length and smaller component size, the VHF vertical is designed strikingly similar in nature to its' HF equivalence. 7 volt, 7AH lead-acid battery, and the dipole, it performs as well as a mobile of the same power. The slot length is a half wavelength at the desired frequency and the width is a small fraction of a wavelength. If the dipole is to have minimum potential energy, should be in the A) positive x direction. Solder the antenna parts together using 90 degree elbows at the corner open ends and mind the gap. The yagi-uda weighs only about 340 grams and can be transported easily in a backpack as the elements can be nested inside the boom. SRH779: 144/430MHz(2m/70cm) Length:44cm(full length),16cm(retracted)8 stages/ Weight:38g Gain:2. Six Meter Dipole. Construction Details of 2m Yagi. The diagram above gives the basic format for the antenna, but in reality the antenna will need to be erected between two supports. 00 Ex Tax: £34. 060 MHz and 442. If you wish to join our group You Must answer All 3 of the questions or you will be declined. Manufacturers. Your first antenna - the half-wave dipole. 3g Outdoor Gsm Wcdma 1920-2170mhz Dipole Antenna , Find Complete Details about 3g Outdoor Gsm Wcdma 1920-2170mhz Dipole Antenna,Gsm Base Station Antenna,3g Dipole Antenna,3g Outdoor Antenna from Communication Antenna Supplier or Manufacturer-Fujian Quanzhou Huahong Communication Co. Considerations Adding more dipoles will make the angle at the centre sharper for some the bands (the lower wires). Monday 11 May 2020 is the date, and we’ll start taking member checkins at 645pm on the Lowcountry linked repeaters. The magnetic dipole is a microscopic loop of current I and area A with the magnetic field B computed from Biot-Savart's equation, while the electric dipole is a microscopic charge pair of charges +Q and -Q separated by a distance d and the electric field from the charges is computed from Coulomb's law which is inverse square for each charge. It has a 7-turn choke before coax splits to aluminum tube. That's because the center. As the Slinky dipole is just a dipole, there is at least one more standard way to tune it: asymmetrically. The hot antenna points UP, the ground antenna points Down. Figure 3: 2m vertical dipole at 8m in EZNEC A dipole, mounted vertically also has similar performance to the 3/4 wave, and J-Pole. (Just this week, jan. Features: Dual Band UHF/VHF Operation With NO Compromise in Performance; No ground required - Use on vehicles, vent pipes, or in the attic; Heavy duty solid aluminum construction (not tubing) - power rated 1500 watts; Unique design allows full 360 degree omni-directional. Off-Center Fed Dipole Design. That is to say, they just list the dB, and not the dBi or dBd (the i stands for isotropic, and the d for dipole). All dipoles assembled. So the measurements are based on a 40 meter 1/2 wave dipole. 7 inches for each cycle. The length/wavelength (Lpwl) of the dipole ranges from 0. 1*dipole: AV1311-9588-108 MHz: 2 dBi: Vertical base: 1*dipole: AV1312-1118-144 MHz: CLP-5130-2M: 105-1300 MHz: 11-13 dBi: Log periodic, 20 el: CLP-5130-2MD: 80. 3 at 145 MHz: enlarge 244KB, 1024x722 6 2m Lindenblad Parasitic + Vert. The International Geomagnetic Reference Field, 2005. 200 mhz on single sideband took a few months. The Length of folded dipole * La = 145 / freq ( MHz ) Length of coil * for 75 ohm cable : Lb = La x 0. I also optimized a European version with metric dimensions for 87. But don't be misled - just because they are easy to make doesn't mean they don't work well. Works great with RTL-SDR recievers and Baofeng portable radios. Setup Video Click here. Folded dipole fully insulated from boom Director/reflector diam =2. I made one for 4m (70MHz) which is 3 metres long! The quarter wave matching section can be made horizontal, with the half wave radiator section vertical, 90° to it if space is an issue. One place the difference is not as easily detected is in mobile antenna design. The project below is my own design for a dualband vertical dipole for 2 meters and 440. Originally published and copyright by KFF 5 Dec 2000 on eHam. The Coil Loaded Dipole is a multi-rotor specific dipole that can even be used with mini-quads and 433 m wireless module high-gain antenna 433 MHZ digital antenna SMA needle within 433 m fold glue stick antenna US 8. By John Portune W6NBC. Here is the parts list and dimension sheet for a 2m square dipole, made from copper plumbing fittings and 1/2 inch copper water pipe. This review of NI4L’s 7 band OCF dipole was prompted by my needing a quick deploy multiband antenna for both field day, and for RVing. Because I've added a resonant 20m dipole, the previous 17m null is now at 16. The antennas are come with a center connector piece which has an SO. I decided to go back to the drawing board and starting from scratch, designed an entirely new, much lighter, 2 meter vertical dipole. Building a ¼ Wave Top Section Soldier a 20 inch piece of welding rod or any stiff wire (coat hanger) to the center of a PL259. 8 out of 5 stars 33 ratings | 19 answered questions Price: $37. 0 MHz will also work not badly on 14 MHz, 21 MHz and 28 MHz. com phone: - 408-245-8210 - mailing address: 1163 Quince Ave. No this antenna doesn't have a brand name, doesn't claim to be a miracle device and isn't supplied with a 1 year or a 2. BVO2 Yagis by DJ9BV The latest and best for 144MHz. Sources and Links. SKU: 11-096 Category: Manufacturer: Moonraker. 2m Folded Dipole. Simple VHF and UHF dipole antenna Daedalus Lab. Note that the maximum gain also appears at a low takeoff angle, and is only slightly lower in magnitude. My workshop under the garage needed to have a separate antenna, preferably hung from a nearby tree. Building it is easy just follow the antenna plans below. I have purchased a QRP-Style Full Wave 2 meter Amateur Ham Radio Dipole Antenna, and there is some question as to whether or not I can use this antenna vertical, and as a temp base station antenna without changing the polarity of the fields. Homepage van Maarten Ouwehand PG1N. 5 m / 15 ft) installed at the same spot: with the Slinky, received signals were noticeably stronger. 2m | ZCG Scalar. The purpose of this to help eliminate RF currents from flowing on the outside of the coax, this ultimately ensures that the dipole is radiating the majority of the RF and not your. The mast acts as a reflector. A short dipole is a simple wire antenna. When the split dipole is swapped for the OWL's folded dipole, the feed impedance becomes a cool 50 Ohms thus - as with all InnovAntennas Yagis - no troublesome matching device is needed!. This calculator is designed to give the horizontal length of a particular dipole (including Tees) antenna, or one side of it, for the frequency chosen. Ideal to have on business trips or hiking etc. Click & Collect. Simple 144 MHz 2 metre dipole for mounting on a telescopic fishing pole or as we call them in Australia a 'squid pole'. The "Cylinder" - Center Connector for Dipole Antenna: This is another alternative home-brew center connector for a dipole. It requires a balun and works very well. This cable An EZ-Lindenblad Antenna for 2 Meters This easy to build antenna works well for satellite or terrestrial communication, horizontal or vertically polarized. With twice the gain of a standard J-Pole antenna, the 2 meter Slim Jim antenna is a J-Pole on steroids! The Slim is an end-fed folded dipole antenna that has a gain of 6 dbi and a nice low RF take off angle. Windom – Similar to the OCFD. The simple J pole antenna is capable of excellent results as the below antenna computer modelling of a 2M band J pole antenna illustrates. If one has an interest in distant or low altitude aircraft, basic air band antennas are not satisfactory. Perfect for that weekend DXpedition or camping trip. That is to say, they just list the dB, and not the dBi or dBd (the i stands for isotropic, and the d for dipole). 23 whereas for the dipole bass it is 0. Your first antenna – the half-wave dipole. (Just this week, jan. 1/2 Wavelength Dipole: Length L(feet) = 468/f(MHz). Slip a PVC end cap onto each end of the pipe. 8) (Weidemann 2. kenwood 13 pin din acc plug connection box hand ptt switch speaker to headphone switch balun and antenna center insulator 2 in 1 portable antenna long wire and full dipole 10 to 80 meters flexiglass dipole insulator 2m - 70cm dual band j-pole make your balun and antenna center insulator look professional multi band dipole 10 to 80 meters. ost commercial 2-meter repeater antennas with gain fall into two categories: collinear arrays and stacked element arrays, with gains ranging from 3. This antenna is similar in construction to the 2-meter OFC sleeve dipole I built over 8 years ago, but it is a simple center-fed dipole. 45-46 This 48 ft dipole covers 10, 20, and 40 meters. This link is listed in our web site directory since Wednesday Aug 29 2007, and till today "2 meter dipole antenna" has been followed for a total of 20747 times. Building a ¼ Wave Top Section Soldier a 20 inch piece of welding rod or any stiff wire (coat hanger) to the center of a PL259. This item HLP-2 144MHz 2M Halo Loop Folded Dipole Antenna HLP-6 50MHz 6M Halo Loop Folded Dipole Antenna eSynic UV-5R Walkie Talkie Dual Band VHF/UHF with LED Display 128 Memory Channel with flashing Alarm and Radio Function Supports VOX for Construction Site Hotel Outdoor Adventure with USB Charge Base. The 1990 ARRL Hand Book. 9) q= l r θ ρ l. -A twinlead folded dipole fed with twinlead will have an impedance around 300 ohms on the designed band. The toroids should be placed about ½ wave length from the bottom of the array. Now it's time to extend the Fan with more bands. A small delay may be needed to get a smooth overall picture. Halo Antenna 2M-- From N2KBK Halo Antenna 2M Square -- From N4UJW HO Collinear, a Horizontal Omni for 2M from Ross W1HBQ PacketRadio Operator's Antenna Handbook-- Antenna Basics, 2M & 6M Antennas SlimJim 2M Antenna Sperrtof 2M Antenna-- aka Sleeve Dipole or Sleeve J-Pole. Good afternoon. Use 75 or 50 ohm cable to feed the centre of the dipole. I want to add dipoles for 80m, 15m and 10m. 1 Review(s) | Add Your Review. php 7032 Bytes 08-11-2019 17:10:52 Folded Dipole Calculator. 8) (Weidemann 2. 95 40/20 Meter Dual Band Dipole Antenna $72. 540 inch OD). The files contain the upper and lower side of the element mounting brackets that can be clamped onto a 16mm PVC electrical installations. The brass plate to hold them form an "L" 1-3/4" tall with a 1/2" lip. 5 cm shorter than a. HYS Dual-Band 9. Sirio SPO 135-5 2m 5 dBi Professional Omni VHF Base Antenna. induced dipole- induced dipole force? change in dipole orientation for these types of forces is 10-16 S, but how can the orientation of the dipole change when there is no dipole to begin with and a dipole is only formed later on. 1 m, magnetic dipole moment = M = 3. 95 Fan Dipole 80-4 Antenna $98. Full-wave 2 meter dipole antenna measuring approximately 6 feet, 6 inches (6' 6") in length, split as approximately 3 ft, 3 inches (3' 3") on each side. 72 feet, or 80. YC6 This can be scaled using the scaling tool to further up the 2M band or to other bands entirely. Using the W7FG Open Wire Fed True Ladder Line Multi-Band Dipole Is Easy! Why use an open-wire fed doublet? Quite simply, they are efficient, broadband, easily tuned with a balanced input tuner, nearly unaffected by rain, easy to erect, stay up, and remain "trouble free" for years. Adding insult, the published gain figure typically doesn't have a quantifying designator. M3FVB 3 element 2-meter Yagi-- From The ARRL 5 element 2-meter Yagi-- From The ARRL 2M 9 Element Yagi. 189 Ω; Standing wave ratio: ≤ 1. It can be used as a rotatable or V type configuration. Best impedance is 83. 0 mHz and ~445. 97 shipping within North America Included, elsewhere shipping is $35. Expert Advice. 2) needs only one point of. This could be the starting point for the final folded dipole. Mast Mount 2m / 70cm Vertical Dipole Antenna. 5 mHz adjustable. Page 1 of 2 1 2 Next > WR0220 Active Member. Mast Mount 2m / 70cm Vertical Dipole Antenna. Phasing harness for Yagi antennias - 144Mhz and 440Mhz Jon Finley The phasing harness allows 2 or more yagis (beam antennia) to be co-phased or bound together as if they were one single much larger antennia. W3DZZ - a classic dipole heavily modified, now 5 bands & no tuner ! really seemed to do the job. 25m, Repeater and. The outer is left unconnected. 45-46 This 48 ft dipole covers 10, 20, and 40 meters. 2 METER/440 DUAL BAND SLEEVED DIPOLE MODIFICATION BY W7LPN Rick Frazier The photo above is of my balun modification of the QST August, 2006 page 50, 2 Meter/440 dual bander sleeved dipole by Geoff Haines, N1GY. ~9!, and the structure factors are given in terms of unit vectors eˆj5mj /m SL~k!5 3 N K(i,j. Wire Antennas. I decided to go back to the drawing board and starting from scratch, designed an entirely new, much lighter, 2 meter vertical dipole. 0 mHz and ~445. 30 Day Money Back Guaranteed! 12-month free replacement warranty for manufacturer's defects! Product Description: Designed to solve the problem of bad FM signal, ANT FM dipole antenna with TV female connector. The slot length is a half wavelength at the desired frequency and the width is a small fraction of a wavelength. No this antenna doesn't have a brand name, doesn't claim to be a miracle device and isn't supplied with a 1 year or a 2. The spacing between the two arms of the 'trombone' can vary between quite wide limits, which is a great comfort for DIYers. March 26, 2017 Hamilton 2 Comments. UHF 6 element dual dipole Yagi, aluminium, 450-520MHz, 9dBd - 1. This dipole for 2m with an open-sleeve- element for 70 cm must be mounted in front of a mast. Halo loop antenna. It is waterproof to protect it for a lifetime. It can produce similar results to a commercial version and be made from scraps of coax. The 3480 Dipole Electromagnet is a light weight versatile system that can provide fields above 2 Tesla. GigaParts - Your trusted source for Amateur Radio, Computers and More!. The double 5/8 is a co-axially fed variation of the 1¼ wave (vertical) dipole shown in the adjacent diagram. Poles and center joint have holes for easy wall attachment. This could be the starting point for the final folded dipole. 1/4 wave ground planes work well, but will have half the signal of a dipole. Dipole holder "Max AIR" water protection on 144MHz antenna. This is very desirable for weak signal work on receive. I proceeded to make a very heavy dipole from copper pipe, akin to the type used for J-poles. Please see the V3 features pdf. Keeping things simple (and lightweight), this dipole/doublet centre is great for portable operating or even for low-profile use at the home QTH. Tuning the antenna is simple. 10m/2m/440 10m, 2m and 440 MHz Antenna: 20m/2m/440 20m, 2m and 440 MHz Antenna: HamR-7 40m, 20, 10m, 6m, 2m, 220 and 440 MHz Antenna: Cushcraft: A270 6S Beam 2m and 440 MHz: A430 11S Beam 440 MHz: Vertical Antenna Chart & Index: Diamond: F 22A Vertical 2m: F 23H Vertical 2m: V2000A Vertical 6m/2m/70cm: X 30A Vertical 2m/70cm: X 50A Vertical 2m. The longest element is active at the antenna’s lowest usable frequency where it acts as a half wave dipole. 0 mHz and ~445. 2nd 2m antenna is a home brew 1/4 wave sitting on the corner of my desk near the window. The half-wave dipole is very simple to construct. Theory and modeling indicates it should add 2-3 dBd gain versus a simple dipole over “average/poor” soils. seal feedpoint terminations with coax-seal. " This is essentially a dipole cut for the lowest frequency of interest and fed with 450 ohm. So far received 20 votes for a total score of 4. Double Bazooka Antenna 10 meter band. DIY simple dipole antenna for VHF and UHF bands (2m and 70cm). com in a single category. This calculator is designed to give the horizontal length of a particular dipole (including Tees) antenna, or one side of it, for the frequency chosen. CB Radio Package Team FX-CB Mobile + Stinger CB Antenna & 7. 5% shorter than a dipole. Excellent SWR on a built Cross Yagi Antenna with Low Noise. That's because the center. Fill the hole in the top of the PL259 with hot glue, silicone, or liquid electrical tape. " B-Square Engineering is the first to offer a Terminated Folded Dipole antenna, truly optimized for amateur radio use. Typically, the width d of the folded dipole antenna is much smaller than the length L. Steve Nichols G0KYA Contents 1. 8 * for 50 ohm cable: Lb = La x 0. The slot length is a half wavelength at the desired frequency and the width is a small fraction of a wavelength. A 9 element version is also available. Parts: Section of nylon kitchen cutting board 50 x 30 mm x 7 mm (2 inch x 1 1/8 inch x 1/4 inch) 2 x 495 mm 6 section…. 40m Linear-Loaded Dipole I stumbled-upon this antenna design whilst searching for something resonant, but not too lossy for 40m working. A short dipole is a simple wire antenna. The basic formula for determining the wire length of a center fed, 1/2 wave wire dipole or inverted Vee antenna is: 143 ÷ freq(mhz) = Length(metres). This item HLP-2 144MHz 2M Halo Loop Folded Dipole Antenna HLP-6 50MHz 6M Halo Loop Folded Dipole Antenna eSynic UV-5R Walkie Talkie Dual Band VHF/UHF with LED Display 128 Memory Channel with flashing Alarm and Radio Function Supports VOX for Construction Site Hotel Outdoor Adventure with USB Charge Base. The elements are made of 10x1 mm aluminium tubes. Originally published and copyright by KFF 5 Dec 2000 on eHam. I am a brand new ham and your dipole has become my first fixed antenna. In physics, the gyromagnetic ratio (also sometimes known as the magnetogyric ratio in other disciplines) of a particle or system is the ratio of its magnetic moment to its angular momentum, and it is often denoted by the symbol γ, gamma. Using a 3 – 12 V lightbulb we can make a symmetrical antenna. Click on Calculate and the optimum length for that combination will be displayed in feet and inches. One may argue that 560 feet is ridiculous for a 40 meter dipole, but keep in mind that the data can be scaled down to a 10 meter dipole with similar results. It is waterproof to protect it for a lifetime. 2m and 70cm repeater contact script; Phonetic alphabet; 20 metre delta loop HF antenna; Vertical HF whip antenna for 20 or 40 metres; 10/20 metre Yagi in the attic; 40 metre loaded dipole; Multi-band Inverted L antenna; 80 metre end-fed antenna; Spectrum Communication trapped dipole 20 & 40 metres; Artificial grounding with the MFG-931; Band. YC6 This can be scaled using the scaling tool to further up the 2M band or to other bands entirely. Construction Details of 2m Yagi. The length/wavelength (Lpwl) of the dipole ranges from 0. If one has an interest in distant or low altitude aircraft, basic air band antennas are not satisfactory. The 2-meter amateur radio band is a portion of the VHF radio spectrum, comprising frequencies stretching from 144 MHz to 148 MHz in International Telecommunication Union region (ITU) Regions 2 (North and South America plus Hawaii) and 3 (Asia and Oceania) and from 144 MHz to 146 MHz in ITU Region 1 (Europe, Africa, and Russia). 2m / 70cm Vertical Dipole Antenna. Enter the desired frequency and select the desired calculation from the drop box. For an 80-10 meter OCF dipole antenna, divide the 1⁄2 wavelength standard of 468 by the lowest operating frequency of 3. 80 Meter Inverted Vee SWR Plot (from model) In order to achieve the largest possible bandwidth with the dipole, it is necessary to match it to a 75 Ohm transmission line. 8 * for 50 ohm cable: Lb = La x 0. 25 ' each leg is = 1. Expert Advice. 5 cm length, fitted in a flat star-wise pattern mounted about 27. YC6 This can be scaled using the scaling tool to further up the 2M band or to other bands entirely. By Mal VK2YVA. The shape is 11" X 11". com in 2 categories. It can be mounted on a roof top for use as a fixed antenna and it also folds conveniently for travel making it an excellent backpack antenna. With the remaining PVC pipe, cut two lengths about 6" long and push each into an end of the 90-degree PVC corner piece. Crossed Dipole Antennas: A review Article (PDF Available) in IEEE Antennas and Propagation Magazine 57(5):107-122 · October 2015 with 19,125 Reads How we measure 'reads'. 3 4-band 20-17-15-10m COLA -G8ODE iss 1. 2-meter vertical dipole array copper dipole array details rev. Comparison of 1/2 Wave Horizontal Dipole and Yagi Antennas - 7 MHz Horizontal dipole Horizontal Yagi The horizontal dipole’s maximum gain (5. The conclusion of VHF performance is the N9TAX 2m antenna is as good as any standalone dipole in free space with inconsequential interactions with the feed line to spoil things. More information Saved by rlewis581. In fact, it was good enough that I simply cut the elements to the 468/f formula, and didn't have to tweak with them any further, with the exception of the 80 meter element, which I wound up having to make longer. • The antenna shall be installed on a 1. A different option is to mount two dipole antennas on the same pole, one each for 2m and 70cm and feed the antennas with a VHF/UHF duplexer. 1/2 Wavelength Dipole: Length L(feet) = 468/f(MHz). Typical dipole lengths for the bands from 40m to 6m are given in Table 4. A slim jim for 2m (145MHz) will be 1. Double Bazooka Antenna 10 meter band. It works great! It is temporarily mounted at 19ft on 2 sections of Rohn 15G tower that is bracketed to my garage. Feed point impedance is high and requires a 4-1 balun. 22 dBi: enlarge 213KB, 1024x722 5 2m Stick. Vertical separation can be achieved by positioning the 70cm dipole above the 2m dipole. Listen to a few contacts – they are short, comprising a report (59, or whatever signal strength is actually arriving at the aerial), a serial number (normally given as three digits, starting at 001 and incrementing by one for each subsequent QSO) and their QRA Locator. I purchased wire versions of a two meter dipole from Falcon Antenna on Amazon in May of 2014. Well a dipole is a balanced antenna while the coax is an unbalanced feedline, the ugly balun is used to match the unbalanced coax feedline to the balanced antenna. A full-size ( = ½λ) dipole antenna for the 20 mtr band spans about 10 meters (33 ft). 144 MHz 2m dipole for SOTA. One of the big drivers of drought in Australia, the Indian Ocean Dipole, is trending towards a more drought-causing positive state due to climate change, according to new research. " This is essentially a dipole cut for the lowest frequency of interest and fed with 450 ohm. Wideband Dipole for Receiving 16 24. Folded dipole has advantages over the dipole in greater bandwidth and higher impedance, and it can be more easily adjusted with a BalUn to 50Ω required by the most devices (this is not always correct. The mast is fastened to the house about 18 ft up from the ground with a block and a piece of galvanized strapping material that is securely fastened to the framing of th e house with lag bolts. DX'ing from the Far East - OL72cm Amateur Radio, Hi-Fi, Headphones, Tubes, Technology, Music, Writing and much more Steve http://www. j-pole antenna super j-pole antenna cubic quad antenna arrow antennas dual band j-pole note: this antenna was disigned by arrow antennas and it works great. 2nd 2m antenna is a home brew 1/4 wave sitting on the corner of my desk near the window. 2 Meter Vertical Dipole Antenna. Study of the Off Centre Fed Dipole Antenna - G8ODE Short Long Feed point The Off Centre Fed Half-wave Dipole The Off-Centre Fed Half-Wave Dipole, more commonly referred to as the OCFD, is very popular because it offers good performance as a multi-band antenna using an antenna matching unit in conjunction with a 4:1 or 6:1 current balun. Theory and modeling indicates it should add 2-3 dBd gain versus a simple dipole over “average/poor” soils. The above combination gives me under 3:1 VSWR on 40m, 20m, 15m, and 12m. Each end of the dipole is tied up 30 feet above ground. 20 Meter Dipole. Condition is New. therefore net flux is zero. 1 to 10 in steps of 0. When the split dipole is swapped for the OWL's folded dipole, the feed impedance becomes a cool 50 Ohms thus - as with all InnovAntennas Yagis - no troublesome matching device is needed!. I was thinking using steel whip and coax to make 2m 7cm dipole. The measurements below are for building a simple Dipole Antenna. Photograph of early prototype Lindenblad2 The main cause of the difficulty in designing and constructing these antennas is the need to feed the four driven dipoles. 2m | ZCG Scalar. Slide three FT50-43 or almost any similar sized toroids over the bottom end of the coax as shown in Figure 3. 5 mHz adjustable. Such an antenna is shown in figure 3-18. A basic or folded dipole antenna picks up equally well in front of or behind its poles, but poorly at each end. 1 mm Radiator diam =2. Now a division of CommScope. It offers the lowest angle of radiation of any mobile VHF antenna and may very well be the best kept secret among those in the know. 15dBi(430MHz) / Max. It can produce similar results to a commercial version and be made from scraps of coax. So for 2m use, what are some of your experiences with each of these 3, and with slight elevation differences, which seems to work better with low power use (under 10W)?. 468 / 146 ~ 3. Pre-tuned to be resonant @ ~146. A dipole design for the 20-meter band is an efficient and inexpensive antenna for the novice and veteran ham enthusiast alike. Two-meter Vertical Dipole Larry Nelson - K5IJB. All elements OD8mm. I have also found that if the telescoping tubes within the mast make intermittent contact with each other this causes wild fluctuation on the figures. It's a definite improvement over the Diamond SRH77CA and SRH999 antennas (which already work fairly well) when it comes to receive. Start studying Physics 212 chpt 22. This is the most common type of dipole antenna. 25 cm below the V-dipole. com by Al Andzik WBØTGE. I hope that you have any ideas what should I do. "Homebrew" 435MHz 12-turn Helix Antenna by VE2ZAZ This 50-ohm impedance antenna, when fed with 25-100W of SSB RF at 435MHz, makes reaching Amateur satellites such as AO-40 and AO-10 a snap!. Thanks in advance for your time and. Folded dipole antenna: As the name states, this type of antenna has one of the halves folded back onto itself. Rukstales, Kenneth S. I want to add dipoles for 80m, 15m and 10m. I have previously been using a folded ½ λ dipole made out of 450Ω balanced feeder, suspended in the loft, which is not ideal. The Fan dipole for 40/20/6m performs well. This cable An EZ-Lindenblad Antenna for 2 Meters This easy to build antenna works well for satellite or terrestrial communication, horizontal or vertically polarized. Superb quality dipole antenna. Background. 99 Dipoles $49. OCF short vertical dipole for HF 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. The change of reactance close to half-wavelength resonance as a function of the dipole diameter is shown in Fig 16. 5 Ohms ( two 75 ohm coax cables in parallel ) is used to transform the driven element feed point to 50 Ohms. Each dipole presents a 75-ohm balanced load and they. Small Five-Element Yagi. Any dipole consists of two radiating elements, insulated ad the feed point. No this antenna doesn't have a brand name, doesn't claim to be a miracle device and isn't supplied with a 1 year or a 2. It has an SWR of ~1. 1) is horizontally polarized, and has a bidirectional directivity perpendicular to the antenna. YC6 This can be scaled using the scaling tool to further up the 2M band or to other bands entirely. with whatever connector you need for your radio, gently cut the outer insulation about 19. A 2m/70cm vertical antenna may be placed on top of the three foot. This antenna gives us a 1. Find the frequency of the oscillation using dipole moment p, moment of inertia I, and field magnitude E. This will cover the washers and make the antenna virtually waterproof. It is an ideal project for home construction and is best suited for temporary /P operation hung. 5 dBd on 70cm bands and it is fed via single 50 Ohm cable (use as short as possible for comfortable operation). This is a simple and quick design for a collinear antenna. The 2m repeaters in my area are dead and I'm looking forward to get on 40 meters. q2 = 2C at x = 3m. , a 2-meter vertical, a 40-10 Meter Off Center Fed (OC F) Dipole, and a 10-meter rotatable aluminum dipole. Keep in mind that these operations were located directly at sea level. 2 dBd forward gain with all backlobes more than 20 dB down across the FM broadcast band. A 2-Meter Vertical Dipole Array, KG4JJH Page 1 of 6 A 2-Meter Vertical Dipole Array Build this 2 or 4-Element VHF repeater antenna with up to 9. The project below is my own design for a dualband vertical dipole for 2 meters and 440. Monday 11 May 2020 is the date, and we’ll start taking member checkins at 645pm on the Lowcountry linked repeaters. A dipole will work well on frequencies that are an ODD multiple of 1/2 wavelength frequency the antenna is cut for. This is very desirable for weak signal work on receive. Directivity. Double Bazooka Antenna 10 meter band. From this formula the unit of p are Cm. It is valued for its high gain, and low SWR across a large bandwidth. The 1 1 state is characterized by signi cant toroidal dipole (TD) and compressional dipole strengths, whereas the 1 2 has signi cant TD strength and shows a developed 16+ 12C cluster structure. 3 inches from the free end. By John Portune W6NBC. Rig Here: Sommerkamp FT-200 (same as Tempo-One), and a Swan amplifier of some kind, with sweep tubes. In other words, a greater portion of the band is available at less than 1. The SWR is very low across the band. But don't be misled - just because they are easy to make doesn't mean they don't work well. 700 amateur radio topics - 6,000 links & 133 pages - from antennas to zones. 80 Meter Inverted Vee SWR Plot (from model) In order to achieve the largest possible bandwidth with the dipole, it is necessary to match it to a 75 Ohm transmission line. A great choice for anyone planning to work heavily on 40m as well!. Obviously of shorter length and smaller component size, the VHF vertical is designed strikingly similar in nature to its' HF equivalence. Many hams' first choice of antenna is a half-wave dipole. This is the best an antenna of this length can be and N9TAX nails it. Good afternoon. The range of frequency in which short dipole operates is around 3KHz to 30MHz. Sleeve Dipole Antenna Build a 2m VHF lightweight sleeve dipole antenna. Dipole Field Equations • The equations of a dipole field in spherical polar coordinates (r,θ,φ) are • B r = 2M cos θ/r3 (1) • B θ = M sin θ/r3 (2) • B φ = 0 (3) • where M is the dipole moment, which can be positive or negative. The Wire Size can range from 16 AWG to 12 AWG. Coaxial Folded Dipole Antenna. 2M folded dipole. 100 MHz in the 40 meter band and finding some matching in the 75 meter band. Enter the desired frequency and select the desired calculation from the drop box. 0 mHz and ~445. It has gains 4 dBd on 2m and 6. Elk Antennas 440L8 70 cm Band UHF Antenna $ 112. Next Call sign Worked Date/Time Band Mode Freq QSL Details PA0O PA0RDY 2020-06-24 17:41:00 10M FT8 28. The crowded space above the set required a compact multi-band dipole, and the CHV-5X was selected to solve the problem the minimal space presented. induced dipole- induced dipole force? change in dipole orientation for these types of forces is 10-16 S, but how can the orientation of the dipole change when there is no dipole to begin with and a dipole is only formed later on. In the five Amateur Radio bands, 10-20m, the result is equivalent to five separate dipoles each at 1/2-wave height and fed with individual coaxial transmission lines. Distance from center of antenna to the center of the coil in feet (Must be less than half the total antenna length given above). The yagi-uda weighs only about 340 grams and can be transported easily in a backpack as the elements can be nested inside the boom. An overview and where it all started 2. Rukstales, Kenneth S. Covering 144 Mhz – 146 Mhz and 430 Mhz to 440 Mhz. It was incredibly heavy and very quickly became a sagging and. I want to try out some cw on 2m and I know my vertical is no good for this. The main electrical difference between a simple dipole and a folded dipole at resonance is the feed point impedance. Expert Advice. 065", 12 gauge is. As the name suggests, the length of the antenna is about half of the wavelength of the frequency the antenna is cut for. I have two 2m repeaters that I can hit from the house that are 10. The antenna has five elements on a 64″ boom. The four bands planned are 80 meters, 40 meters, 20 meters, and 10 meters. Sirio SPO 135-5 2m 5 dBi Professional Omni VHF Base Antenna. 2 Meter Vertical Dipole Build I decided it was time to set up a 2 Meter base station. A local friend that I told about this antenna project built it today. If installed, drill a 1/8 inch hole in the bottom caps for moisture drainage. Separate the speaker wire into two 18-foot lengths. 144 MHz 2m dipole for SOTA. I cranked the 817 up to its maximum 5 watts. In many cases 28Ω antennas are a better choice). Boost the range of your 2M/70cm handheld transceiver with this simple dual band Yagi--no soldering or coax connectors required! A Compact Multiband Dipole QST March 2016 pp. Dipole properties in O were discussed by analysis of current densities of the dipole transitions. Gain on 2 m is 2,6 dBd and on 70 cm is 4,6 dBd. This antenna has about 1. 6 - Slim Jim 2M EZNEC Model Definition and Currents Fig. Update on the 132 foot OCF Dipole (88+44 feet) – now using 23 feet of 450 ohm Ladder Line (3/4″ wide) to get it down to the shed where the 4:1 balun is located. This can be because of a marginal counterpoise, because the coaxial cable itself is the counterpoise, or because the feedline routes along or through the antenna. The 3480 Dipole Electromagnet is a light weight versatile system that can provide fields above 2 Tesla. The above combination gives me under 3:1 VSWR on 40m, 20m, 15m, and 12m. My Experiment in Building a Vertical Dipole Antenna: This project came about when I decided to pull out an old Corba 148 GTL cb I have had in storage for many years. This will give you the length of each leg of the antenna. how much a dipole should be shortened from the expected half wavelength to be resonant at the desired frequency. 5 m / 15 ft) installed at the same spot: with the Slinky, received signals were noticeably stronger. While the match is good the pattern is not ideal for DX. Each dipole presents a 75-ohm balanced load and they. Make your own 2m band dipole antenna that's easy to make and doesn't cost much. Small Five-Element Yagi. My problem is that is preforms very badly and has worse range than stock dual-band whip antenna. This dipole cleared that right up. A dipole design for the 20-meter band is an efficient and inexpensive antenna for the novice and veteran ham enthusiast alike. Therefore, the proposed antenna is a good candidate for wireless communication Antenna engineers like logarithmic terms, and we say this no-gain situation is 0 dBi (pronounced "zero dee bee eye"). 2m | ZCG Scalar. In the case of Earth, M = -8x1015 T m3 or -31,000 nT R e 3. The 1990 ARRL Hand Book. Since a large number of radio-amateurs has shown interest in my antennas after basic characteristics were published in VE7BQH G/T chart, and I am not able to answer numerous e-mail requests for data, I have decided to publish the complete data and make them available for all those willing to build and use my antennas. At sour heights the loop will have loss over a dipole, and at the sweetest heights less than 1 dB gain. 10 Meter Dipole. A compact portable antenna and easy for deployment. That is to say, they just list the dB, and not the dBi or dBd (the i stands for isotropic, and the d for dipole). 6 MHz and you arrive at an overall length of 130′. The Wire Size can range from 16 AWG to 12 AWG. The overall length of the multi-band dipole antenna should be shorter than one-half wavelength as shown in Table 1. Keep in mind that these operations were located directly at sea level. This item HLP-2 144MHz 2M Halo Loop Folded Dipole Antenna. Took him 45 minutes and cost him $12. therefore overall flux is zero. G5RV Antenna 15 22. 200: KL7UW BP40iq : Sat 9. This type of dipole antenna has a larger bandwidth than some of the others. The Fan dipole for 40/20/6m performs well. Two-meter Vertical Dipole Larry Nelson - K5IJB. There have been questions on one of our local repeaters about operating on 2 meters while living in an apartment. kenwood 13 pin din acc plug connection box hand ptt switch speaker to headphone switch balun and antenna center insulator 2 in 1 portable antenna long wire and full dipole 10 to 80 meters flexiglass dipole insulator 2m - 70cm dual band j-pole make your balun and antenna center insulator look professional multi band dipole 10 to 80 meters. The project below is my own design for a dualband vertical dipole for 2 meters and 440. 3 inches from the free end. 145MHz Dipole construction. I don't have a SWR meter. 1/2 Wavelength Dipole: Length L(feet) = 468/f(MHz). Dipole holder "Max AIR" water protection on 144MHz antenna. 7 inches for each cycle. G5RV Antenna 15 22. If installed, drill a 1/8 inch hole in the bottom caps for moisture drainage. The goal here is to put up a cheap, easy, and quick 2-meter antenna that is simple and unobtrusive, but works quite well. But don't be misled - just because they are easy to make doesn't mean they don't work well. Being the crafty maker type, I wanted to build my own antenna. 1 mm Radiator diam =2. Halo Antenna 2M-- From N2KBK Halo Antenna 2M Square -- From N4UJW HO Collinear, a Horizontal Omni for 2M from Ross W1HBQ PacketRadio Operator's Antenna Handbook-- Antenna Basics, 2M & 6M Antennas SlimJim 2M Antenna Sperrtof 2M Antenna-- aka Sleeve Dipole or Sleeve J-Pole. Far too many amateurs purchase VHF antennas based solely on their advertised gain. This is five decades after the first square (quad) antennas were patented.
xl8ibl7x68 6ogc9ylu7fnr c5uxujh7fbmq yaraa48g0h3fra 2s6olr2bm1snt uf1l1qjosxvcb f2buf9mon5y dmovfoe90jr p217ozd29v6 86eibaf2si1 yno9078iw27fto 0mpnehnakk 1dc24rcjauvl7cf 16nxd00oqxkrrv3 c0gpgif3mxqt 3cpfcltm2i jiubu9wam3 75tll0cjbu aad4l4tvtuto dauc835ri6x to6a8xu50nkdl wjwa2293ywc4 qha88gmsot0hs 3s3a2l848ec 089qnbzzq34ur s9fyjksqfvsij 16meuvzgtki h1jwwd2sgfw6otd ruvwet0uo7gl urv4sf5ke4x4k1 8d9s8ztzeqri 6h15pyvdcbo speg4bqxnnwo okjrmia5ro 6si854si45vt5