2m 5 8 ground plane antenna pdf

You get mfjs rapidtuneradiator for quick accurate tuning. Simple 2 meter ground plane antenna project with pvc support by kc0ynr, malcolm. Quarter wave antennas will behave as dipoles if they are mounted on an infinite ground plane. It is found that a five eighths wavelength vertical antenna has a gain of close to 4 dbd, i. Another problem comes from the fact the 5 8 wave jpole has that unbalanced current in the j part of the antenna. This vertical antenna has 6 ridged aluminum radials inches long each. Comet original gp1 146446 mhz dual band heavyduty fiberglass vertical base antenna 4 2, so239 connector. Mfj 1750 2m 58 wave ground plane antennas mfj1750 free. The closer the antenna is to ground, the closer the source and image become, and more pronounced the null along the ground. The iba 5 indoor cb antenna works great when you cant put a base antenna outdoors. Id planned on sticking it on top of my rooftop 20 mast that will support my g5rv. Find the lowest frequency for which you have minimum return loss. Antenna projects for 144 mhz category is a curation of 148 web resources on, ocf 2 meter sleeve dipole antenna, dish antenna for 2 meters band, the tiny 3.

Radial attach each radial with a 632 screw, lockwasher and nut 20. Constructing a simple 58 wavelength vertical antenna for. Thus the length of the antenna, electrically, is really something other than 5 8 of a wavelength. Mfj 1750 2m 5 8 wave ground plane antennas represent one of the best values in 2meter base station antennas. About portable vhf ground plane the resource is currently listed in in a single category.

Aluminum jpole build john kotecki kd8pvs jason kotecki kd8ucp the original idea came from the arrow. Other 5 8 waves cant work any better no matter how much they cost. When tested with my 2meter ht and vhf wattmeter at 147. Everywhere we look, everything tells us the 5 8th wave has 3db gain.

Describe your experience with the mfj1750 58 wave ground plane 2m base antenna and tell us why you give it the rating you did required. The na4it cheap dual band ground plane antenna here is a neat little antenna that is very easy and cheap to build. The fullwave antenna is voltage fed, so it readily. My operation is mainly working locals, the occasional. When autoplay is enabled, a suggested video will automatically play next. Pg1ns ham radio site 2m projects omnidirectional antennas. The earth ground below the antenna, a conducting surface a. Use our simple calculator to determine approximate dimensions of materials needed to build a vertical antenna. We recommend that you deburr and clean up each part with.

L antenna 5 8 donda in vhf, le antenne piu usate sono le 14 londa e le 5 8 donda. The position of these nulls is also dependent on ground proximity, making their behavior hard to predict unless they are mounted on high towers. You get shunt fed matching network for lowest possible swr over entire 2 meter band. Here is a very simple 2 meter ground plane project that can be used as an emergency antenna, in limited space, for quick and easy setup on field day, camping, or just plain outdoor fun. If i replace it with a 12 wave, granted the swr is the same as the 14 wave, will it give me a little more reach, lets say 3 miles. Doesnt need a complicated matching system, just a series inductor at the feedpoint will do it. This vertical should be mounted at 6 to 8 feet above ground for best performance. Describe your experience with the mfj1750 5 8 wave ground plane 2m base antenna and tell us why you give it the rating you did required. Does anyone know where i can get plans for this antenna. The 5 8th wave is a great antenna misunderstanding example.

One of the most widely used methods is to etch slots on the patch 5,6 or on the ground plane 7, 8. The above is a 58th wave antenna centered on a large flat roof over good flat soil. For someone like me who doesnt want to invest in a large yagi array and a big rotator to turn it, thoughts turn to omnidirectional, horizontally polarised antennas. A ground plane antenna is essentially one half of a dipole mounted vertically. Have a yaesu ft2500m ham radio set up to shift between my car and indoors. A cpw fed dual band notched uwb antenna for wireless. The term monopole is also used to describe this antenna. Your antenna usually works like my 2m half wave ground plane. Mfj 1750s offer a shuntfed matching network that will handle up to 300 watts. Eznec says a 5 8 wavelength 147 mhz gp with 14 wavelength sloping radials 4 in free space is 114j322. It is ideal for technician class hams needing a first antenna, and also a very good emergency antenna for use during skywarn events when you dont want to be on the sky hooks tall in the sky.

Introduction an overview of common ham antennas for portable, base and mobile use, geared towards the new ham. This was not entirely surprising as the there had been some antenna modelling done by others that suggested that the 5 8 ground plane offered little if any advantage over the simpler 14 wave ground plane as a tower mounted antenna as i was utilising them. The 58th wave antenna gain with lossless matching would be 2. Vhf and uhf antenna systems 1821 fig23these drawings illustrate the dimensions for the 144mhz ground plane antenna. However, it assumes you have a very robust ground system to work against. Wouldnt you expect that the maximum radiation would be a few maybe 30 degrees above the plane of the radials, kind of like a 14. Have a maxrad 5 8 wave whip antenna that i think is supposed to be tuned to the rr frequencies, but a quick search hasnt revealed what length is best for a 5 8. Feb 20, 2014 easy to build ham radio dual band 2 meter and 70 centimeter ground plane antenna. Sirio s2016 ground plane antenna cb base station antenna, omnidirectional high power cb balcony or temporary install antenna omnidirectional designed to work without ground plan antron 99 with ground plane kit lowers angle of radiation for greater range a99ck includes the sets of elements. Sep 15, 2002 designed for hams that do not have room for ground radials. Judd found the slim jim produces a lower takeoff angle and better electrical performance than a 5. Guest what, i can communicate with the other for about 40 km for my place could they have good transceiver and antenna then i have. M2 antennas eggbeater satellite antennas offers exciting new performance characteristics for both fixed and mobile operations and will let you. Rather, it acts like a capacitor between the antenna, and the surface under the vehicle in question.

Every ham likely has made a 2 meter antenna from a discarded cookie can or a pizza pan. When the antenna is erected and the ground plane is in place, grab your antenna analyzer or vna. Mfj makes a phased 5 8 wave 2 meter antenna that also works as a 12 wave vertical on 6. Shortening the stub to move the maximum vswr point higher in frequency is easy. A basic antenna like a dipole is selfcontained and requires no ground plane. A j has an exceptionally low, to nearly flat, angle of radiation of near. Requiring a new 2 metre band antenna for local fm simplex and repeater communication and after evaluated a couple of the main contenders for the project i settled on the 5. Maple leaf communications antenna calculator vertical. Request pdf a cpw fed dual band notched uwb antenna for wireless medical applications objective.

The j requires no additional or special ground plane. The slim jim variation of the jpole antenna has characteristics and performance similar to a simple or folded halfwave antenna and identical to the conventional jpole construction. Paying attention to the effect of the ground plane, using the right materials and matching the impedance of the antenna to the impedance of the coax and the coax impedance to the receiver impedance can all play a role in wringing out the last drop of gain from the antenna. That will put the antenna at about 35 above ground.

So why would anyone use a 5 8 wave antenna if they have to go through all that extra work. The trick is getting the feedpoint to match with the feedline. In order to navigate out of this carousel please use your heading shortcut. This shopping feature will continue to load items when the enter key is pressed. Im wanting to use it to create a full wave or 5 8 wave ground plane antenna mounted on my house roof for receiving railroad traffic 161mhz on my scanner. By john portune w6nbc the whip was a piece of coat hanger soldered into a banana jack, or a 19. A quater wave antenna s radiation pattern like a dome. Radial slowly twist the wire while pulling it to keep it taught. A fiveelement quad antenna for 2 meters by jim reynante. Imagine a simple 5 wire 2m ground plane antenna in freespace where the four resonant radials are horizontal. A quarter wave ground plane antenna has a radiation pattern that produces maximum gain at about 25 degrees and a half wave antenna drops that angle to 20 degrees, and the 5 8 wave antenna further drops that angle to 16 degrees.

Groundplane antennas for 144, 222 and 440mhz for the fm operator living in the primary coverage area of a repeate r, the ease of construction and low cost of a 14. Thats a ground plane with a 5 8 wavelength electrically radiator. Antenna projects for 144 mhz category is a curation of 148 web resources on, simple vhf antenna, 2m big wheel antenna, feed line dipole for 2 meters. The main category is antennas for 2 meters band that is about antenna projects for 144 mhz. Cb antennas low profile, tunable, fiberglass, steel. Other useful information would include your experience with similar products, infomation on a product that you would purchase instead of this one, and so on. I across the repeater portion at the upper end of the 2meter band. Constructing a simple 58 wavelength vertical antenna for 2. This link is listed in our web site directory since tuesday feb 21 2012, and till today portable vhf ground plane has been followed for a total of 826 times. Nov 03, 2018 however, it assumes you have a very robust ground system to work against. A fiveelement quad antenna for 2 meters by jim reynante, kd6glfpo box 27856san diego, ca 92198 if your station is located on the fringe of the repeaters coverage area, youve come to the right place. Before starting to build the antenna, you can stiffen up ordinary 14 gauge copper. The earth ground below the antenna, a conducting surface a least.

As the name indicates the antenna ground plane acts as a. The element and radials are made from t832 drawn aircraft aluminum tubing. The ground plane provides a return path for the rf current much like. The new 14 wave ground plane antenna received the vk6rec repeater also at s3. When 8 radials are used instead of 4, the swr improves to 1. If you want to use coax, you need the feedpoint of the antenna to be 50 or so ohms. Here is a picture of the antenna mounted on the new mast. High performance 40 meters vertical without radials. It has gain and wave angle comparable to a fullsized ground plane antenna with radials. Vhf and uhf antenna systems 1821 fig23these drawings illustrate the dimensions for the 144mhz groundplane antenna. These antennas are most often available as magnetic rooftop mounts. Of all simple vertical antennas over ground, the 58 wave radiator has the lowest angle of radiation, however the base of the 58 antenna presents a relatively low impedance, not the high impedance offered by the. But unbalanced antennas, like the vertical 14 wave, 5 8 wave, and collinear styles do need a ground plane to function properly.

In an effort to keep the price on maco antennas down, we have decided not to clean up all the burrs and rough edges on the parts. My 5 8 2m gp is able to tickle repeaters about 90 miles away right now, and its about 10 agl live on a bit of a ridge. After all, a ground plane antenna provides a nicer match. A 5 8 antenna is nothing more than a main radiating element that is 5 8 of a wavelength long. The 5 8 wave antenna takes some of the energy from its top and distributed to the side, so that it covers more ground radius.

I wanted high efficiency 40 meter antenna with lowangle radiation. Most terrestrial dx activity on 144mhz uses ssb, cw or digital modes and horizontal antennas. This is about a 1hour project, or maybe a little extra to check swr and trim the wires to the correct length. The concept of a ground plane is roughly to build a antenna half as long as a normal selfcontained one, then add a mirror so that it looks like a complete antenna from the antenna side of the mirror. Ground mounted antennas are often very easy and convenient to use. Balanced antennas, based on the dipole design, dont require a ground plane, this would include half wave antennas, jpoles, yagis, and beams. What is the impedance of the 58 wavelength ground plane. However when it is not possible to ground mount an antenna because of ground conditions or it is necessary to elevate the antenna, another solution is to use a ground plane. Adding a coil in series with the antenna at the base is one such method of matching. The rf power wave reshaping help taking some of the rf power emitting vertically to the horizontal radiation. This horizontal slot antenna, cut into the reflector of a tv dish, is both the master of disguise and high in performance. These inexpensive antennas offer a gain antenna basestation solution thats durable and effective. A new planar ultra wideband uwb antenna of dual notching bands is proposed and presented.

The j antenna goes back many years, long before i became a ham. Constructing a simple 58 wavelength vertical antenna for 2 meters. This shortened easytobuild vertical, with noradials, is made from surplus military camouflage poles. But, when it placed higher on the ground more then 5 m height, the quality of transmit is get worse. This is whats contained in the antenna you show, and all the 5 8 wave whip antennas used for mobile installations. When used as a vertical radiator against a ground plane this translates to a length of 58 wavelength. Antennas 101 mecklenburg amateur radio society, inc.

A close look at this familiar makeshift antenna may surprise you. A matching device of some sort must be added between the antenna and the feedline if you wish to feed it with coax. Choose from quarterwave, halfwave, the powerful 5 8 wave, 34wave, or fullwave, and calculate minimum lengths of required radials, and then shop for your needs on our other pages and select from our inventory of aluminum, fiberglass, wire, coax, connectors, and other parts and. This connector is expensive, so one might prefer to use the less expensive so239 connector. When mounted on the 4radial portable ground plane described above, the same antenna shows 1. To determine the frequency for which this length is 5 8 wavelength, multiply the frequency by 2. Building my eggbeater ii omni low earth orbit satellite antennas for 70cm i only had vertical 5 8 ground plane antenna fro 70cm and 2m band. Ham radio vhfuhf mobile installation by mike baker, w8cm. I needed a good 2m antenna to hit the callaway amateur radio league carl clubs repeater, about 5 miles away and found the 2 m ground plane project. Various approaches to achieve bandnotched function have also been introduced. Nevertheless, most of them possess the lowest operating frequency at about 3ghz, which makes.