Learn tips for folding yagi, softening the tubing, bending jig and make all waterproofing CB antennas Lots of information on fabricating CB antennas Homebrew your own inductors Cannot find the inductors you need for an antenna, a tuner or amplifier? Build your own it is easy! Installing dipole insulators Installing your dipole end insulators, a beginner guide to proper setup wires to insultaors. A coaxial cable trap is a parallel resonant circuit that is usually inserted in an antenna element to enable multiband operation.
Contains pictures, plans, parts list of very popular ham antennas along with experimental types. Link to a spreadsheet for calculating the mast bending stress based on wind speed and antenna cross sectional area. Improving ground connection, computer analysis of the antenna, modelling sample antennas pdf file [ Hits: Votes: 6 Rating: 9.
Homemade 70cm Yagi Beam Antennas
This tool, is based itself on the simultaneously comparison between two antenna, directly in dB. It gives you an idea of the change in wire length needed to move antenna resonance a specific number of KHz. Selecting the best metals for antennas evaluating the conductivity factor. What kind of wire will you use? This analysis may change your plans. Learn tips for folding yagi, softening the tubing, bending jig and make all waterproofing [ Hits: Votes: 29 Rating: 5.
Here you can find hints and tips on diy wire antennas [ Hits: Votes: 1 Rating: 10 ] Home-brew Antennas - Notes on homebrewing antennas by Chris G4CYA, from gamma matching, to phasing antennas, splitters and combiners, baluns and measuring techniques. This technique has been implemented to build a Quadrifiliar Helix antenna.
The elements and boom are assembled separately in most cases. Once they are all together set up 2 tripods in the assembly area and put the boom on them. Wire antennas need to be made a bit long and cut to resonance. They are affected by height above the ground and surrounding objects.
In order to get an idea of the right place to start, certain formulas are generally accepted. This is true because the boom influences the electrical length of the elements. In this article JH Reisert explain with drawings techniques on mounting yagi antenna elements to a boom [ Hits: Votes: 2 Rating: 8.
Ham Radio operators review new sites every day sincefor potential inclusion in the Directory, and to evaluate the best place to list them. Antenna Homebrew Antenna construction notes. Operating Modes Operating Aids. CB Radio Antique Radio. Home : Antennas : Homebrewing Techniques. Antenna masts. Cables and Connectors. Test equipment.
SWR Meters. RF Safety. Impedance Matching. Search only in "Antenna Homebrew". Add a new link. The DXZone is the largest human created and maintained library of web sites dedicated to Amateur Radio, currently lists The type of antenna largely depends on the type of ground station. A no rotator ground station will benefit from a different type of antenna omnidirectional than a rotator based ground station directional.
The two different approaches are explored below. In addition to the choice of antenna the choice of location for the ground station will have an effect on the quality of observations. This type of ground station will require an antenna that will give a broad coverage from its fixed position.
It is therefore not just the antenna that needs to be considered but also the proximity of buildings, geography or metallic structures that might be in the path of a line of sight between the ground station and satellite. Typical ground stations have had success with simple wire antennas that can be commercially bought or made at home. These have anecdotally been used for successful satellite work but should be avoided. The following are considered suitable choices:.
Build the Pennyloop UHF Antenna
A rotator based ground station is able to make use of directional antennas. These will have a directional gain, meaning that you will need to point them in the direction of the satellite but the signal you receive will be stronger and for longer. They will allow much lower to the horizon passes to be received and more successful observations. These are not complex antennas but the choice will depend on the type of satellite and there are variations on the main types: yagi, helical and quad.
A common type of antenna that is either horizontally or vertically polarised. Simple to construct and suitable for a large number of satellites. A less common type that are circularly polarized. This will protect the ground station from the elements in all but extra ordinary conditions. The design can be found here and construction guide here. Toggle navigation. Discussion View source History. Jump to: navigationsearch. Non-Rotator Ground Station Omnidirectional This type of ground station will require an antenna that will give a broad coverage from its fixed position.
The following are considered suitable choices: It is highly recommended that you use a mast-mounted Low-Noise Amplifier LNA with these antennas. Commercial Antennas Homebrew Antennas. This page was last edited on 18 Marchat QRZ Forums.
Guys I want to make my own TV antenna. I am tired of the old rabbit ears. I know this isn't ham radio related. But same skill set. First off, what should be the best antenna type to build? Yagi, beam, dipole or jpole? Could I use some of my RG58 coax? If you have any pointers or usefull links let me know. Thanks, 73s. N6OSBDec 3, Lets get geometric Think Rhombic. A pair of parallelled Rhombics will have a feedpoint impedance close to Ohms.
Non-resonant Rhombic antennas are quite broad banded and if properly designed will have quite a bit of gain across the wide bandwidth of the antenna. Have fun with your tv antenna project. I recently threw the cable company out of my house with their equipment.
This then left me looking for an econimical way to get tv.
The obstacles I have may not be relevent to you, unless you live a good distance from any city or transmitter site. For me the closest is 30 miles away. The result was better then nothing by far. Due to lot configurations and the idea of being quick about it, I came up with one side dropping down at a 45 degree bend from feed point and the other half is horizontal. I was able to pull in ch 2,4,9, 13,14,27,46 with this design. Not fully satisfied, I attached another random length of wirethat now runs about 50 feet out from just the hot side of feed, in conjunction with the previous install, and was able to improve reception on ch 9 which works for me as the shows my wife wants to watch are on that channel.
I notice a big signal improve in the evening especialy on the lower end of the dial. My configuration is by far less then ideal as it lys across the house for a part of it then over to the trees to be tied off there, which leaves me with a "L" shaped design in the mostly horizontal plane. I am sure I will here how I shoulda used something else, but like many I felt the need to just make something work so I didnt have to here the nagging.
I have another antenna that I made that seems to work well but only when in or near a metro area. It was the left over parts from a broken bicycle wheel, so I took the spokes and mounted them onto a a 2x2 piece of wood, designed around the VHF half of the dial, it works ok on UHF, but could be better.Orfanidis - Lots Of Math! Also shows basic station interconnections - From Hamuniverse. This document has been recently upgraded to take advantage of the CSS system and have also added a button to allow the note to be downloaded as a PDF.
Harold H. Dipole Height -- How High??VHF UHF antenna basics - DIY antennas from surplus 800mhz antennas for 2m 70cm and dual band
With a tuner covers the amateur radio HF bands from 40 - 10 Meters. The SWR is usually acceptable on the 3rd harmonic, although that is partly due to the increased feeder losses on But SWR is not the whole story.
This is usually not so severe to make the antenna unusable, and may be considered a reasonable compromise for the dual band coverage. If you do the simple math you will see that on you will have almost a 2 wavelength antenna, which is becoming what we call a "long wire" on the HF bands. As you probably know, a long wire radiates with multiple lobes, the largest of which are toward the ends of the wire.
In other words, most of your signal will be radiated up toward the sky. The reason for the coil in commercial dual band antennas is to phase the antenna currents so you actually end up with two colinear elements which both radiate at low angles, reinforcing each other and providing gain. Without the phasing coil you get multiple undesirable lobes. It is simple and works OK.
This antenna can be built from low cost materials available from the local hardware store. Old TV Antenna Scheme. Submitted by Gary Ruehle. My son and I built a dual 6 element stacked yagi for 2 mtr a couple of years ago. TV antennas were all the building materials we used.During the recent devastating Black Forest fire in central Colorado, my good friend and colleague, Randy, had great difficulty maintaining solid radio communications through our local repeater from his home.
Our local hams kept the repeater very busy during the days of the fire relaying the latest information gleaned from emergency response links, commercial sources, AREA and RACES volunteers, and more. It was a valuable resource in our community for rapidly disseminating fire information. His home is located just on the leeward side of a hill from the repeater that is about 7.
After the fire emergency, Randy decided it was time to upgrade his station for more reliable operations in the local area. While he plans a future station upgrade to a more powerful mobile-base transceiver, he sought first to improve his home antenna such that he can use the HT in the short term and integrate a mobile-base transceiver later.
Commercial purchase or homebrew? I use three or four different ones in my home and in portable station operations of various flavors. Most commercially available antennas are going to provide great performance and even greater convenience! In virtually all cases you can simply buy-and-install with only the requirement of connecting a feed line to the antenna. If you want to open the wallet instead of the tool box, a commercial antenna is your best choice.
There are many simple designs provided by a whole world of hams to choose from. Yagi directionals for VHF ops are great projects, if you seek that directional boost in signal gain for your situation. With a homebrew solution you can save some money, but be prepared to invest the time and effort necessary. And remember, every antenna is a compromise, so carefully check out the design and performance reports before finalizing your decision. Single band or multi-band antenna?
With multi-band radios now so readily available to hams, the majority of folks are likely to desire a multi-band antenna with which a single feed line can be used. Ditto for only, or 6m band ops. Consider the local radio resources available to you and how you wish to use them, and then decide what band capability your station and antenna require for those operations. Trees can help conceal antennas or even serve as a growing, green mast!
Antenna location? The type of antenna you obtain and even the specific model or design will likely be influenced by your chosen mounting location. Many hams who live in covenant protected neighborhoods like to mount antennas in the attic to keep them out of sight. If you plan to mount your antenna outdoors you may wish to ensure you get a sturdy model that can withstand high winds and that provides moisture protection at the coaxial cable feed point. If you mount in a tree, be sure the motion of tree and limbs will not damage or dislodge the antenna.
Location and antenna selection are closely coupled, so think it through before you purchase or brew. Antenna gain? Depending upon your situation you may need a little boost in your effective radiated power, or the effective signal strength from your antenna.
Many antennas provide signal gain, boosting the effective transmit power at the antenna. Comparison of isotropic, dipole, and omnidirectional patterns of signal strength.
Antenna gain is defined in comparison to a reference antenna. Recall that a 3 dB increase or decrease is a factor of 2 comparison. So, an antenna offering 3 dBi will provide double the signal strength in its main lobe transmission pattern as compared to the same transmission with a theoretical isotropic antenna that radiates equally in all directions, like a sphere.
If your antenna specification says 6 dBd, it provides main lobe gain 4X that of a dipole antenna. The signal pattern from such antennas tends to be disk-like in a horizontal omnidirectional pattern, degrees around the antenna. So, the signal strength that the theoretical isotropic antenna spews in every direction of the spherical pattern is vertically squeezed into this disk pattern, providing relative signal gain.
A dipole antenna produces lobes with the strongest signals at right-angles to the radiating element orientation. The weakest signals are out the ends of the radiator. So, a dipole has gain as compared to the spherical isotropic antenna pattern. Pay attention to whether the gain is expressed as dBi or dBd when comparing antenna performance, and realize that a lower gain figure in dBd may actually be better than a higher figure in dBi.The range from 54 to MHz covers between three and four octaves.
Any general "television antenna", even an enormous log-periodic beam, will be a compromise. Before the digital transition, a TV channel was simply the numerical designation of its 6 MHz wide range of frequency. A digital broadcast signal is a data stream that includes metadata like the virtual channel number or other identification. People were accustomed to be being "Channel 18". It now broadcasts on MHz, physical channel 11, but it identifies as channel A new low-power station WPBI started broadcasting in lateon both physical and virtual channel 16, at MHz.
The Single-Bay Gray-Hoverman antenna definitely is a compromise, trading size against performance to yield a small size that can easily be used indoors or in an attic. Several web pages have SBGH plans, a good example is here. It worked about as well as could be expected of such a compromise. I live in a masonry building with some steel reinforcement, it's an effective shield keeping radio signals out. The SBGH antenna had to sit out on the balcony to receive the two stations, where it mostly captures signals scattered from nearby buildings.
I next built a pair of folded dipoles sized for the two center frequencies of and MHz. I used 1" PVC pipe for the frame, drilling and then screwing in small sheet metal screws to serve as the feedpoint and the dipole end supports.
Plus the nearby PVC pipe, plus whatever other approximations might be appropriate in this rough design.
That works out to dipole lengths of My dual folded dipole outperformed the Single-Bay Gray-Hoverman antenna. Given the all-or-nothing reception of a digital TV signal, I can't make any meaningful comparison. But, sitting in the same location on a desk near the window, it receives both stations, meaning three digital channels from each. Have I swept impedance versus frequency? Measured and compared received signal levels?
The pair of folded dipoles receives both stations while the Single-Bay Gray-Hoverman design does not. Dual folded dipole television antenna.I am writing this article in a way in which I hope newer hams can understand, build and learn about antennas. In order to design a Yagi we have to learn what a Yagi is.
A Yagi is a Directional antenna made of up elements. The 3 Major parts which make a yagi are the driven element, reflector and director. When cut and placed at a calculated distance On a Boomthe elements will cause the RF Power to be sent radiated or received in whichever direction the antenna is pointing to. On the lower frequencies HFa Yagi would be the antenna of choice by Hams. There is a couple of down sides to having a Yagi or Beam antenna on HF. First off, HF Yagis are huge. HF Yagis are expensive and so is the tower and rotor, so the parts alone could add up to couple thousand dollars.
There are also several other factors that would steer someone away from a Yagi. Those factors could be age, housing restrictions, living in an apartment, permits, handicap, property size, neighbors, and more stuff than I list.
The lower the frequency, the larger the antenna. The higher the frequency, the smaller at antenna. On the Yagi that I am building, the design is based on the length of the boom antenna rather than the gain.
So you want to build a Yagi. To start off your going to have to know what material your going to be using. There are many different types of aluminum and I would say that T6 Aluminum would be the best choice for antenna building.
The reason is that T6 is more weather durable and easier to work with compared to other aluminums. The downside of T6 is when it comes to bending. If it comes to other designs of yagis that use a Hairpin or folded dipole then I would take the type of aluminum into consideration.
This all depends on personal preference. Reason I ask that is if your designing this to be on sideband only, you will only need it to design it to work best over the span from Another downfall of the Yagi is that it has a narrow bandwidth. If you start transmitting out of that span, it could create signal loss and high SWR causing the transmitter to step down power to prevent damage or actually damage older radios.
Why build an antenna that is not going to radiate the power going to it? So now we have everything we need to start designing a Yagi-Udi Antenna. Well… How do you design one? This is a fork in the road and there are many different ways you could design one too many to list.
There are different programs for different types of Yagis and there are different mathematical formulas for different or the same types of yagis. This program is based off the N umerical E lectromagnetics C ode for modeling antennas. Basically it will tell you if your antenna is going to work and how well it will work on or near the frequency you designed it for.
Another great thing about 4NEC2 is that it will perform adjustments on your antenna to optimize it for the best results. So if you are somewhat close to a good antenna, the software if the programed right will make it even closer. This software however is slightly or very difficult to use for a new person in the hobby.
I adapted to the design portion of the software because I have knowledge in CAD Computer Aided Draftingbut I had to do a lot of reading about the electrical properties and how to make the software do what I want.
I am not going to dive in depth explaining this software. However, I will show you how I used the software to create the antenna.