The drop off on the horizon is only a db or so and insignificant. Analysis of the effects of rectangular ground plane on. A balun is probably unnecessary due to using a well tuned antenna but i would use it anyway. That said, pretty much anything will act as an antenna.
Droop angle the graph on the right shows the effect of an increasing angle of droop. It is possible to simulate this function by replacing the real earth. Everywhere we look, everything tells us the 58th wave has 3db gain. A vertical element and a ground plane is just one possibility for what those two halves can be. The 58 wave antenna is easier to tune and not as cranky about mounting location and nearby objects as the jpole. As the name indicates the antenna ground plane acts as a simulated ground. 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. Another antenna with vshaped ground has been designed for rfid readers 14.
A quarter wave ground plane is the simplest way to go and will perform well as well as a jpole with the least amount of hassle. Ground losses depend on many factors like the antenna mounting, how the antenna is wired and bonded, where the ground plane mass of metal begins, how much metal is used beneath the antenna in order it radiates properly at low elevation antenna ground plane is not to be confused with an electrical ground. A ground plane must satisfy both length and width dimensions outlined below. Ground losses depend on many factors like the antenna mounting, how the antenna is wired and bonded, where the ground plane mass of metal begins, how much metal is used beneath the antenna in order it radiates properly at low elevation mar, 2010 the ground plane essentially makes the 14wave antenna look like a dipole due to the theory of reflections, the ground plane creates an image of the antenna below. Make a rope eye on one end with about 6 of extra length twisted around the long part of the wire. If you try to use standard ground based cb equipment with a vehicle or in a situation that requires a no ground plane antenna, youll likely experience both high swr levels and extremely poor performance.
A typical mobile cb antenna does not transmit horizontally, it radiates in a downward pattern. See chapter 6 for more details on practical groundplane verticals. Antenna gains are calculated with an infinite ground plane. This antenna is cut specifically for an elevation of 16 feet at center and 56 feet on the ends. The firestik fg2 2 foot nogroundplane replacement antenna comes in black or white and will replace a broken or damaged antenna from one of firestiks kits. Vhf and uhf antenna systems 1821 fig23these drawings illustrate the dimensions for the 144mhz groundplane antenna.
No ground antennas and coax are unique cant be mixed with standard cb parts. No ground plane antenna systems have a very specific purpose. To learn more, see our guide to using no ground plane cb antennas. Concentrated ground plane booster antenna technology for. Uses simple, easy to find components that can easily be replaced repair.
The antenna must have a ground plane to be efficient, and ideally the ground plane should spread out at least a quarter wavelength, or more, around the feedpoint of the antenna. The radio waves from an antenna element that reflect off a ground plane appear to come from a mirror image of the antenna located on the other side of the ground plane. Oct 02, 2014 simple 2 meter ground plane antenna project with pvc support by kc0ynr, malcolm 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. Quite often a vertical antenna or a random wire is one side of the antenna and the earth ground is the other a flat plane. The feed line is connected between the bottom of the helix and the ground plane. Simple 2 meter ground plane antenna project with pvc support by kc0ynr, malcolm 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. In the ground plane antenna style whip antenna, the plane consists of several wires. This is a stainless steel radial plate designed to be mounted on the same one inch post that you would use to ground mount our antenna.
The plate is 9 inches in diameter and has 20 points to connect radials. When your vehicle has little or no metallic surface area for the antenna to use as its needed counterpoise your decision process should be. Meanwhie the takeoff angle appears to be in the range of 15 to 20 degrees for most cases at low heights. A groundplane antenna is a form of dipole antenna designed to work with an unbalanced feed line. Pdf effects of the ground plane size on radiation pattern.
A ground plane antenna is more of less one half of the dipole and mounted above the ground plane. By don hc4w4bws get on the air on 20, 17, 15, 12 and 10 meters with one vertical ground plane antenna. What is the effect of using different number of radials with. Effects of ground plane size on antenna gain electrical. 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.
Jun 07, 2010 the 58 wave antenna is easier to tune and not as cranky about mounting location and nearby objects as the jpole. The closer the antenna is to ground, the closer the source and image become, and more pronounced the null along the ground. You have an ineffective antenna it does not radiatereceive well. If you omit the ground plane from a ground plane antenna, then there are only two possibilities for what happens. A metal surface the larger and flatter, the better is required underneath the cb antenna to launch the signal out into the atmosphere. A 5 band 20 10 meter multiband hf ground plane antenna project. Mar 30, 20 helix antenna a conducting wire in the form of screw thread fed by power source. A quarterwave monopole is a ground plane dependent antenna that must be fed singleended. Ngp no ground plane antennas at cb world no ground plane ngp antennas. By don hc4w4bws get on the air on 20, 17, 15, 12 and 10. As it was demonstrated in 1420, the antenna bandwidth can be improved by achieving a ground plane length of approximately 0. Fusionner pdf combiner en ligne vos fichiers pdf gratuitement.
Quick view firestik fg3 3 foot black or white nogroundplane replacement antenna. The fg648 series, more info no ground plane ngp cb antenna kits were specifically designed to solve the problems associated with the lack of ground plane counterpoise. In this paper, a study is conducted to investigate the performance. Item 1 generally comes under the topic of tuning, where you bring the antenna into resonance or wherever it was designed to be tuned. An antenna ground plane is not to be confused with an electrical ground. A ground plane antenna removes half the dipole and substitutes the ground plane for that. Ground plane and antennas electronics forum circuits. Check out these high quality antenna systems from firestik for motorcycles. 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. The gain for the ground plane is very nearly constant and equal to an isotropic antenna at low heights and real ground conditions. A half cut disc cpwfed printed antenna, with a portion of the ground plane cut, has been investigated in.
This form of antenna requires the use of a connection to ground connection as short as possible, or a ground plane. I am trying to design a patch antenna, so i ran several fullwave simulations and increased the ground plane size each iteration, extracting the gain. Make the simplest, cheapest, easiest no ground plane cb base antenna in the world in 6 easy steps. A simple ground plane antenna you can buildfor 146, 223 or 440 mhzin no time flat. A dipole antenna is effectively a resonant length of wire broken in the middle to allow the feedpoint to be inserted. 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. To learn more, see our guide to using noground plane cb antennas. The 58th wave is a great antenna misunderstanding example. Vertical antennas vertical aerial types electronics notes. I have looked online a bit and it seems to me that the general belief is that the larger the ground plane up to a certain extent, the better. Nogroundplane antenna systems have a very specific purpose.
Since the geometries of the reconfigurable slotring antenna working at different frequency bands are similar, a single slotring antenna with different ground plane sizes at 6. Buy failsafe 14 wave professional grade tunable ground plane antenna. Ease of fabrication and cost makes the ground plane antenna one of the popular antennas in communication systems. They should be the system of choice when you have no other choice. A groundplane antenna is more of less one half of the dipole and mounted above the ground plane. The effects of ground 33 with its four groundplane radials elevated well above lossy earth. This form of vertical antenna is popular in many instances because it is able to provide gain over a quarter wave vertical, focussing more. Pdftk ne fonctionne pas avec les formulaires pdf en version 1.
Failsafe 14 wave professional grade tunable ground plane. This increases the space required and windage of the antenna. A ground plane is not a metal roof gutter, a window frame, a downspout or any other piece of metal that is long and thin. Tv antennas free delivery possible on eligible purchases. Noground antennas and coax are unique cant be mixed with standard cb parts.190 602 285 213 1457 626 261 1465 101 604 531 1081 1531 394 293 661 505 437 781 614 1044 691 627 1552 1495 884 885 334 1176 248 786 942 1419 113 149 168 910 1258 1167 1177 737 568 693 185 635