To attach the radials to the flange of the so239 i use small boltnutlockwasher sets in 440 size about 12 long. Apr 08, 2012 the first antenna that you should consider building is the quarterwave ground plane antenna for the 2m band. Vhf eggbeater antenna from on6wg f5vif quick and simple 2 meter ground plane project via hamuniverse 2m yagis. Plus the antenna also have the great low noise floor and wide bandwidth typical of our other antennas. The jpole is one antenna that probably should not have a balun for the above reason, should you decide to try this poorly conceived antenna. Ground plane 14 wave vertical portable or emergency vhf. A simple example illustrating this point is given in figs 3 and 4. Fig25simple groundplane antenna for the 144, 222 and 440mhz bands. Given that you are usually using this on 2m or 70cm locally, often with a repeater, you dont need much of an antenna. This calculator can be used to design a quarter wave ground plane antenna, with radials. I put a little bend in the ground plane wires to attach them to the so239. Homebrew vhfuhf ground plane antenna not to scale 20.
This link is listed in our web site directory since monday aug 4 2014, and till today simple vhf uhf ground plane has been followed for a total of 873 times. Mar 30, 2014 build a simple vhf uhf scanner antenna a police scanner antenna for the price of parts. The quarterwavelength, ground plane antenna is made up of one vertical element, called the driven element, and four radials. The basic j is reported to have 3db of gain over a. Ground mounted antennas are often very easy and convenient to use. Antenna array theory can be found in almost any book devot ed to antennas. Then just get an so239 socket and some wire to make your own ground plane. Antenna projects for 144 mhz category is a curation of 148 web resources on, the tiny 3, magnetic loop for the 2m band, feed line dipole for 2 meters. Though we made it for the ham bands, it was resonant at 9 mhz with the current length of its elements. After moving to south america i needed a simple antenna to get back on the air. This is the vertical radiation pattern of a ground plane antenna over a socalled perfect ground. Therefore, if a radio station is broadcasting at a frequency of 100 mhz. This link is listed in our web site directory since monday aug 4 2014, and till today simple vhf uhf ground plane.
As you can see in this photo, the fittings from the tie strip have been both bolted and soldered onto the flange of the so239. Ground plane 14 wave vertical the ground plane or 14 wave vertical will give a good amount of gain over a rubber duck type antenna. This antenna allowed me to toss some paracord up into a tree and hoist the antenna as high as i could. Hi all so i wanted to move the antenna on our fire depts tanker to the roof of the trucks cab but the roof is fiberglass. Jan 10, 2016 diy simple dipole antenna for vhf and uhf bands 2m and 70cm. Thursday, september 7, 2017 diy antennas the vhf uhf folding ground plane antenna v2. I did some searches and found that i can put sheet metal on the inside to do this. William orr, radio handbook, 22 nd edition, howard w. Generally, antennas for vhf bands are mounted as high off the ground as practical to overcome the limitations of. Due to the complexity of the original article submitted to us and the task of getting all of the details on the web, the complete article is available for download here in its entirety. The radiating vertical element and the radial wires are both 14. Balanced antennas, based on the dipole design, dont require a ground plane, this would include half wave antennas, jpoles, yagis, and beams. There are many comparative evaluations suggesting that there is often little difference in performance with the 5. This type of base gives a very simple mounting to the ridge cap.
Simple, cheap diy radio scanner antenna receive only, for. Most terrestrial dx activity on 144mhz uses ssb, cw or digital modes and horizontal antennas. If you are just getting experience in building antennas or you are an old pro, here is a simple and fun project. The earth ground below the antenna, a conducting surface a least. Our uhf slim jim antenna delivers up to 6dbi of gain on the 440 470 mhz uhf bands, which is almost twice the gain of a jpole and 5 times the gain of a 14 wave ground plane antenna. 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.
The first antenna that you should consider building is the quarterwave ground plane antenna for the 2m band. The gpk01 pairs easily with nmo hf, vhf and uhf antennas such as the dual band nmo72 or tri band tb320a. Contributions from michael vk3fmic, shane vf3fsrg, lou vk3alb, and peter vk3zav. Some use the aircraft skin on metal aircraft, some use a foil or aluminium sheet inside the aircraft, some use a coil of wire built into the base of the antenna and others use wires radiating from the base of the antenna. Strip the insulation off of two 8inch pieces of the copper. For vhf and below, as the elements get bigger, some more structured design is needed. Pg1ns ham radio site 2m projects omnidirectional antennas. Vhf uhf antennas by kb0yki jpoles, super jpole, omnidirectional, quads, yagis vhf eggbeater antenna from on6wg f5vif quick and simple 2 meter ground plane project via hamuniverse 2m yagis.
My son and i built a dual 6 element stacked yagi for 2 mtr a couple of years ago. Its a simple antenna to build with a good bandwidth, it doesnt have any gain over a dipole because its dipole. The best relatively lowcost 2m only ground plane type antenna ive ever found been doing this 50 years now, on 2m fm is the hustler g6144. They are normally ground plane independent meaning that the ground plane is inbuilt and are mounted vertically on towers or the side of buildings.
Dipoles aerials with 2 elements must not have ground planes. For 2 meters, each part is cut to be 19 inches and then soldered to a coaxial connector. The monopole antenna requires a direct connection to ground, meaning the metallic structure of the vehicle. Base loaded no ground plane antennas vhf base loaded chrome coil antenna, no ground plane 9 base loaded field tunable 3db gain antennas 10 base loaded chrome coil antennas, no ground plane 11.
But unbalanced antennas, like the vertical 14 wave, 58 wave, and collinear styles do need a ground. It features wireend loops for safety sharp, straight wires are hazardous and convenience its top loop lets you hang it off high objects for best performance. The resource is currently listed in in a single category. Thank you for all those questions, please keep them coming. A practical approach to hf and vhf antennas, plus antenna. However, aesthetically speaking, the rod antenna on a roof or fender does not satisfy modern design emotions, so car designers try to avoid simple rod antennas on their cars. This antenna is perfect for those hams living in the primary coverage area of the repeater for 2 meter use. Sep 05, 2016 a simple experiment to demonstrate how ground plane radials affect the performance of an antenna a 14 wavelength monopole whip was tested under following conditions.
Trying to make 14 wave 2m ground plane directional qrz. Modifiing a pmr or frs radio antenna for better receive performance. About simple vhf uhf ground plane the resource is currently listed in in a single category. It has essentially the same radiation pattern and gain as a vertical half wavelength dipole or a jpole. Simple homemade outdoor 868mhz antenna groundplane. Vhf adjustable ground plane 1186mhz gp3 the gp series is a range of omnidirectional unity gain adjustable ground plane antennas ideal for local area coverage when a high gain antenna. 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. Twayrdio uhf vhf mobile ground plane antenna enhance signal uhf female to pl 259 male connector for car radio mobile transceiver 3. It is a quarter wave vertical radiator and four radials that simulate a ground for the radiator. Trying to make 14 wave 2m ground plane directional qrz forums.
When 8 radials are used instead of 4, the swr improves to 1. The arrl welcome pamphlet contains instructions on building a simple ground plane antenna and specifically comments on its use by handytalkies. Diy antennas the vhf uhf folding ground plane antenna v2. In this video from peter parker vk3ye, we see how an old vhf television antenna can be recycled into an efficient 6 meter ground plane antenna. 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. In theory the ground plane should extend out to infinity, but in practice a. The one pictured below is for receiving adsb aircraft signals on 1090mhz, again using scrap copper, but this time a purchased ntype chassis socket. Apr 20, 2017 building a great portable antenna for vhf or uhf. They are very easy to build and will perform better than the antennas that come with most handhelds.
If needed, it can be disassembled into a very small bundle no longer than the longest element. Three simple home brew 2meter antennas american partisan. A 5 band 20 10 meter multiband hf ground plane antenna project. One of the most common antennas is the ground plane antenna which is basically a 14 lambda driver element and 3 or 4 reflector elements creating a artificial ground. Before starting to build the antenna, you can stiffen. Easy vhf antenna n1gythe simple approach to ham radio. The polarization of an antenna refers to the orientation of the electric field it. The vertical element and radials are 332 or 116inch brass welding rod. Simple ground plane antennas n1gythe simple approach to. Build a simple vhfuhf scanner antenna a police scanner. Constructing a simple 58 wavelength vertical antenna for 2 meters. Antennas for automobiles 195 nearly anywhere on the vehicle. It works even better if you add reflectors below the vdipole.
With this our ground plane antenna for vhf ham bands was ready. In this view, we retain the concept that ground is an integral part of the antenna and an ungrounded vertical must have some structure that replaces the real ground. I pruned the radials to bring the whole antenna to tune. It is entirely made of noncorrosive aluminium and assembled on a strong diecast base which allows an easy and safe installation assuring very good performances. This handbook presents basic propagation theory, the fundamentals concerning. How to build a ground plane antenna with images ham. The antenna model fq2 is a development from the basic configuration of a groundplane. This antenna was a omnidirectional and all though it hit my. How to build a ground plane antenna for vhf ham band. When tested with my 2meter ht and vhf wattmeter at 147. A simple aerial can be constructed from 10mm aluminium tubing fixed to a mobile aerial base. Radial attach each radial with a 632 screw, lockwasher and nut 20. It is a gain type colinear omnidirectional vertical for 2m only and is ten feet long tall but very rugged and a great design.
The antenna must have enough ground plane to be efficient, and ideally the ground. Whats the difference between a dipole and a ground plane. It was now time for some testing, i had joshi kaka to test the antenna with his antenna analyzer. My operation is mainly working locals, the occasional. Ease of fabrication and cost makes the ground plane antenna one of the popular antennas in communication systems.
The broad vertical beamwidth offers excellent null fill for consistent signal coverage. The quarter wavelength vertical antenna is a simple and effective form of. A quarter wave monopole mounted against a perfect ground will have an. Please practice handwashing and social distancing, and check out our resources for adapting to these times. Dummies guide to aircraft antennas cumulus soaring. Drive around and findcollect old tv antennas that people are throwing away. A ground plane antenna is a form of dipole antenna designed to work with an unbalanced feed line. Basic antenna design considerations for enocean based products. 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. Homebrew antenna options include the simple tiger tail or 14 wave 19 at 2 meters of wire with a crimp connector to attach under your rubber duck. Radial slowly twist the wire while pulling it to keep it taught. Simple 2 meter ground plane antenna project with pvc support by kc0ynr, malcolm here is a very simple 2 meter ground plane project. A simple ground plane antenna you can buildfor 146, 223 or 440 mhzin no time flat. 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.
Works great with rtlsdr recievers and baofeng portable radios. Mar 01, 2017 this antenna works like a charm on noaa, meteorm2 and iss. Actual antennas can vary between these two extremes. To attach the radials to the flange of the so239 i use small boltnutlockwasher sets in 440 size.
I ground independent aerials are specifically designed not to need a ground plane. The gpk01 is a premium ground plane kit for an easy solution to provide ground mount for a base or field mounted antenna. In conjunction with a very competitive pricing due to quick development and easy manufacturing, monopoles are the first choice in the automotive industry. This unit features quickdetach elements to facilitate for easy and fast.
This is, of course, the familiar ground plane antenna being viewed as an asymmetrical dipole. Groundplane antennas for 144, 222 and 440 mhz arrl. This dropping of the ground plane causes the antenna to radiate its radio. There are usually four radials, three being a minimum, but you could use up to six. Get on the air on 20, 17, 15, 12 and 10 meters with one vertical ground plane antenna. The main category is antennas for vhf uhf bands that is about antennas for vhf and uhf radio bands. Jpoles are high on the list of myths, that fail to live up to the claims. A vertical antenna with radials bent down at approximately 45 degrees will have a natural impedance around 50 ohms making it a good match to the radio in use. Ground plane antenna for base station service working on 170230 mhz by means of the tuning diagram enclosed.
A copper cactus is fun to build, but a ground plane will usually out perform it. As you can see in this photo, the fittings from the tie strip have been both bolted and. All antennas require a ground plane of one sort or another. While this conceptual framework has served us well for over 100 years, it tends. Easy vhf antenna a new way to build a 14 wave ground plane antenna finally, an improvement on the so239 14 wave ground plane antenna. The first home page another old home page submit a project. While every type of antenna requires an rf ground of some sort, not every one needs a ground plane. It is also incredibly simple to build consisting of quarter wave elements for the vertical and radials.
I wanted to make something simple that would be reliable and not require a balun or any impedance transforming, so i decided to build a quarter wave ground plane antenna for home. A ground plane antenna is more of less one half of the dipole and mounted above the ground plane. This creates a reflective ground plane and improves reception notably. The second antenna i built was a 14 wave ground plane antenna. A hawaiibased amateur radio antenna blog focusing on the theory, design, and use of homemade antennas. However, i wonder what the actual capability of this antenna would be. Vhf adjustable ground plane antennas 70175 mhz gp series the gp series is a range of omnidirectional unity gain adjustable ground plane antennas ideal for local area coverage when a high gain antenna is not required or justified. The quarter wave vertical antenna is used at all frequency bands including lf, mf, hf, vhf.
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