This is true with a quarter wave antenna, which needs an extensive ground plane. Groundplane antennas for 144, 222 and 440 mhz arrl. The only part you will need to buy is an so 239 panel mount connector. The antenna specialists asp600 half wave to 58wave groundplane came in three frequency splits. Easy vhf antenna a new way to build a 14 wave ground plane antenna finally, an improvement on the so 239 14 wave ground plane antenna. If you are just getting experience in building antennas or you are an old pro, here is a simple and fun project. Antenna grounding for composite aircraft general information.
Here we have a ground plane antenna mostly used for 144, 222, 440 mhz. Fig 24dimensional information for the 222mhz groundplane antenna. Most hams are familiar with the quarter wavelength groundplane antenna design. These antennas can easily be built for uhf or above by using a chassis mount ntype or so239 connector, some solid wire and solder. The only part you will need to buy is an so239 panel mount connector. It is a design that performs well and exhibits low input impedance, making it ideal for use with ham equipment without the need for special matching techniques. Figure 11 tri band antenna with helical loop not drawn to scale which allows for insertion into a.
May 23, 2005 i once built a ground plane antenna for xmitting on 2m ham, before i got my beam, and i am thinking about making one or two for just recieveing for some different ranges, wondering if there is a site or something with good information on best type of wire to use and lenghts the wires should be from the so 239. A simple ground plane antenna you can buildfor 146, 223 or 440 mhzin no time flat. It features wireend loops for safety sharp, straight wires are hazardous and convenience its. Fig 24dimensional information for the 222mhz ground plane antenna. Comet original gp3 dual band 146446 mhz heavyduty fiberglass vertical base antenna 5 11, so239 connector.
Jun 12, 2007 most hams are familiar with the quarter wavelength ground plane antenna design. How to build a ground plane antenna for vhf ham band. Change from an so 239 to an n and redo the antenna recut the length of the elements. Make a rope eye on one end with about 6 of extra length twisted around the long part of the wire. Whats the difference between a dipole and a ground plane. Another way to look at vertical antennas 1notes appear on page 32. We appreciate scott, na4it sharing it with usnow get building and enjoy this simple and easy dual bander. The standard ground plane antenna consists of a vertical radiator which is insulated and centered between 4 horizontal surrounding radials which extend out from the base of the antenna. Building an antenna can sound intimidating, but its pretty easy once you dive into it. So, a horizontally positioned antenna radiates a horizontally polarized wave. On 6 meters it is more of a 12wave groundplane, so it has somewhat less gain than at 40 mhz. A portable multiband endfed half wave efhw antenna for. Easy vhf antenna n1gythe simple approach to ham radio. I used stainless steel hardware and although the ring terminal and the silver plated flange of the so 239 might accept solder well, the stainless steel does not.
Feb 20, 2018 a 14 wave ground plane antenna is using the reflection in the ground plane to get the effect of a center fed 12 wave vertical. Make the simplest, cheapest, easiest no ground plane cb base. Antenna projects for 144 mhz category is a curation of 148 web resources on, the tiny 3, feed line dipole for 2 meters, ocf 2 meter sleeve dipole antenna. This is a bracket to make a ground plane antenna for vhf or uhf radios. When mounted on the 4radial portable ground plane described above, the same antenna shows 1. Meanwhie the takeoff angle appears to be in the range of 15 to 20 degrees for most cases at low heights. You might want to get a couple of them just in case you damage it on the first try. Apr 09, 2014 is your ham radio ht rubber ducky letting you down. Please dont use so239 uhf chassis parts but use a n style chassis part better for the 868mhz. Trying to make 14 wave 2m ground plane directional qrz.
It is found that for a monopole antenna like a quarter wavelength vertical, the ground acts as a plane to reflect the radio waves so that an image of the top half of the antenna is seen in the earth. Sometimes, though, you need a more efficient antenna thats just as portable as a handheld. Diy tv antenna ham radio antenna radio amateur emergency preparation emergency kits all band dtv electronics gadgets home brewing. Manuels adsb antenna consists of a simple sma connector with flange and some wires cut to the correct resonant length for 1090 mhz adsb. Portable, ground plane for 2 meters made with bnc antennas that you can take down its a compact ground plane antenna for portable use. Antennas free delivery possible on eligible purchases. This antenna is going to be massive, so you better get some friends to help you mount it and have the room on your roof and the permission to do it. This type of antenna is very easy to build and i recommend all beginners to give it a try. The one pictured below is for receiving adsb aircraft signals on 1090mhz, again using scrap copper, but this time a purchased ntype chassis socket.
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. Holes were drilled in the washer to accommodate 4 radials. Simplifies groundp lane antenna construction w6nbc. I was worried about the strength of the connection of the welding rod to the center conductor of the so 239 flanged connector until the friendly gentleman at the hardware store showed me a small device called a 14 brass insert from the plumbing aisle. When autoplay is enabled, a suggested video will automatically play next.
Two 14 wave sections in series with a feedline in the middle. Antenna grounding for composite aircraft cobham plc. Uhf panel mount, 5pack rfadapter female so239 chassis mount 4hole jack flange solder cup rf coax connector for j pole antenna, 14 wave antenna, ground plane antenna. When 8 radials are used instead of 4, the swr improves to 1. Do you want to transmit a stronger signal to the repeaters.
As you can see in this photo, the fittings from the tie strip have been both bolted and soldered onto the flange of the so 239. Thanks to manuel aka tysonpower for submitting to us his extremely cheap adsb antenna build. The cylindrical cap at the right is sized to slip over the end of a 3. Trying to make 14 wave 2m ground plane directional qrz forums.
New hams can build this with little to no experience in antenna building. The gain for the ground plane is very nearly constant and equal to an isotropic antenna at low heights and real ground conditions. It is often the first antenna they buy or build for use on 2 meters after receiving their technician license. This particular ground plane is constructed out of an so239 chassis connector, so the radiator is attached to the center conductor of the. To do this, you must have the mounting screws, washers and nuts make direct contact to the internal ground plane. Note that the better ground conditions give a lower angle. Just put the thing on the back of a so239 chassis mount to make it more pretty and give you a mounting option. The dipole is part of a fan dipole fed with 80 of rg8x and a balun, this ground plane is direct fed with 50 of old rg8 and 20 feet of rg8x. At 1090 mhz, a 14 wave antenna will be tiny with a vertical element of a mere 2. I will show you how to build a complete discone antenna with just materials from home depot and radioshack in one afternoon for about 100 to 150 dollars.
Each radial is evenly spaced 90 degrees apart from each other around the vertical element. Very simple homemade outdoor 868mhz antenna groundplane. Unfollow ground plane antenna to stop getting updates on your ebay feed. At vhf and uhf, it is possible to build yagi antennas with very high gain15 to 20 dbon a. The two most common were asp600b 3040 mhz and asp600c 4254 mhz. An easy way to make this antenna is to use an so 239 coax connector. Ham radio antenna, antique radio, home brewing, circuit diagram, radios, grid, music, ham radio. For this weeks project, we will be building a 14 wave ground plane antenna.
Lengths for a, b, c and d are the total distances measured from the center of the so239 connecto r. The quarterwavelength, ground plane antenna is made up of one vertical element, called the driven element, and four radials. Some people have tried to install monopole antennas internally with a ground plane installed for the antenna to work against and this is just totally bad. Fig a groundplane corner reflector antenna for vertical polarization, such. Resoldering turned out to be a pain, so the next version that i built, used 14 inch copper tubing for the radials. Build your own antenna 14 wave vhf ground plane antenna. Here is the list of parts needed to build your own quarter wave ground plan vertical antenna. I once built a ground plane antenna for xmitting on 2m ham, before i got my beam, and i am thinking about making one or two for just recieveing for some different ranges, wondering if there is a site or something with good information on best type of wire to use and lenghts the wires should be from the so239. Radial attach each radial with a 632 screw, lockwasher and nut 20. I recently built a quarter wave ground plane antenna, so that i could get back on the 4m 70mhz band.
I followed the instructions exactly and i still use the antenna today. This is the first thing you will need to build a quarter 14 wave ground plane antenna. The art of installing antennas internally into composite aircraft has left many people confused and perplexed so i have decided to try to give some tips and information on the subject. Build your own antenna diy quarterwave ground plane on gmrs questions. A portable multiband endfed half wave efhw antenna for 4010m. The picture got me so amused and i was quickly hooked to this hobby. Use a screwdriver and pliers to release one wire from beneath one of the rivets on the 58inch element.
A basic antenna like a dipole is selfcontained and requires no ground plane. Our antenna is now complete except for a way to mount it. The only cb i own is a late 70s sears 40 ch amssb radio, and it just so happens the first contact on the ground plane was on 38 lsb with no amplifier to a station in michigan. Keep in mind that this, and most ham antennas, can be made with parts that you probably already have lying around your home.
If so, ill show you how to build a two meter quarter wave ground plane antenna. Is your ham radio ht rubber ducky letting you down. You can solder the radiating element directly to the connector and use the. These antennas can easily be built for uhf or above by using a chassis mount n type or so239 connector, some solid wire and solder. Radial slowly twist the wire while pulling it to keep it taught. Easy to build ham radio dual band 2 meter and 70 centimeter ground plane antenna. Heavy duty soldering gun wire cutters vise or third hand or another human. A tri band antenna for 2 meters, 220 mhz, and 70cm. Therefore, i used lock washers to reduce the loosening of the connections to the flange.
This ground plane design has been around for years on the internet with atouks guide being the most commonly used, although. Na4it 2 meter 440 dual band vertical ground plane antenna. The parts below are what i used to build the antenna, but you can substitute most of these parts with whatever you have around your house. The drop off on the horizon is only a db or so and insignificant. Click the image to view construction details of the 70mhz quarter wave ground plane antenna. So here is the model for the k8ch antenna, modified and scaled for 20m. The center hole for the bnc to bnc connector was already there. I dont recommend soldering the ground plane radials. I am not going to go into the details on how to built it, because its so simple. Here is the list of parts needed to build your own quarter. This article shows how a dipole and and ground plane antenna are similar but also different. Simple ground plane antennas n1gythe simple approach to.
The ability of an antenna to focus electromagnetic energy is defined by its gain. A simple ground plane antenna you can build for 146, 223 or 440 mhzin no time flat. I built one of these so239 ground planes some time back and at some point it fell over against a concrete floor, breaking off one of the radials. Here, you can clearly see the small section of coaxial cable that connects to so239. A cheap and easy ground plane worldwidedx radio forum. In this case, its a multiband antenna the customer is using it can be used from 700 mhz 2700 mhz so the ground plane required could be anywhere from 464 square inches. This antenna is perfect for those hams living in the primary coverage area of the repeater for 2 meter use. Match the end with the raised circular portion of the connector.
Make the simplest, cheapest, easiest no ground plane cb base antenna in the world in 6 easy steps. The na4it cheap dual band ground plane antenna here is a neat little antenna that is very easy and cheap to build. The j antenna goes back many years, long before i became a ham. A fun project to build and learn how to tune antennas is a. Lengths for a, b, c and d are the total distances measured from the center of the so 239 connecto r. The so 239 coax connector bolts to the radial elements through the bottom of the radial. In this view, we retain the concept that ground is an. Eventually at an angle of 90 the radials will combine and the ground plane antenna becomes an vertical dipole and exhibits an impedance of 75. You can pick one up at radio shack or your favorite electronic supply. A portable multiband endfed half wave efhw antenna for 4010m steve nichols g0kya. This ground plane design has been around for years on the internet with atouks guide being the most commonly used, although atouks design uses a larger so 239.
One of the simplest antennas you can build is a quaterwave ground plane antenna. The little hole on the side is to fill the inside with a resin or something like that to make it watertight. May 07, 2010 here we have a ground plane antenna mostly used for 144, 222, 440 mhz. They are very easy to build and will perform better than the antennas that come with most handhelds. Fig 24 dimensional information for the 222mhz groundplane antenna. A 14 wave ground plane antenna is using the reflection in the ground plane to get the. Ground plane antenna plans for 146 mhz, 220 mhz and 440 mhz solder an inch or so copper tube into the center post of your connector. A portable multiband endfed half wave efhw antenna for 4010m steve nichols g0kya introduction a few people have asked about the 30m antenna norfolk amateur radio club used for its international marconi day imd operations at caister lifeboat this year. Dualband portable noground plane antenna qrz forums. It works fine with low swr, but nearly all the repeaters i want to reach are northish of me and i dont just dont have enough umph to make it into the further ones.
A tri band antenna for 2 meters, 220 mhz, and 70cm antenna. Editors note here is a very easy to build dual band 2 meter440 vertical ground plane antenna that may end up as your primary antenna for dual band operation or for emergency use. Instead use 440 bolts home depot and the 440 nuts to fit them. An easy way to make this antenna is to use an so239 coax connector. Jun 07, 2017 thanks to manuel aka tysonpower for submitting to us his extremely cheap adsb antenna build. Four ground plane radials bolt to the horizontal member at the left of the mast mounting cap. I was worried about the strength of the connection of the welding rod to the center conductor of the so239 flanged connector until the friendly gentleman at the hardware store showed me a small device called a 14 brass insert from the plumbing aisle.
Antenna gain is expressed as a ra tio of the effective radiated output power pout to the input power pin the gain of an antenna is a measure of power transmitted relative. The amountsize of the groundplane required for the optimal performance of a monopole antenna is determined by the frequency you are transmittingreceiving at. He asked what an antenna that doesnt need a ground plane would do if a ground plane was nearby, and i basically said. I use a halfround needle file to make the concave cutout.
N5eses portable vhf ground plane for use with magmount antennas, with pictures. With the efhw the earth or a counterpoise is still important, but not. Below is a quarter wave ground plane antenna i made for 23cm, 1296mhz which is made from offcuts of household mains copper wire and a scrap bnc socket from the junk box. 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. I have made a page showing some images and construction details of this antenna which can be seen here. Place the so239 into position and measure the rod then cut the rod accordingly. As the name indicates the antenna ground plane acts as a simulated ground. Blog antenna ground plane calculation arcadian antenna. When tested with my 2meter ht and vhf wattmeter at 147. One of the most common antennas is the ground plane antenna which is basicly a 14 lambda.
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