Each antenna was assembled, piece by piece, at the. Fractal magic diy hdtv antenna free download as pdf file. Functioning as a trigger diode with a fixed voltage reference, the db3 db4 series can be used in conjunction with triacs for simplified gate control circuits or as a starting element in fluorescent lamp ballasts. The slot antenna can be considered as a loaded version of the inf antenna. The last picture in the segment is a commercial one. This means decibels of gain relative to a standard halfwave dipole antenna. When the feed point is moved to the shortcircuited end of the slot or inf antenna, the impedance decreases. The ability of an antenna to focus electromagnetic energy is defined by its gain. The noise power received from an antenna at temperature can be expressed in terms of the bandwidth b the antenna and its receiver are operating over. Before beginning assembly, make sure all pieces needed are. Pointing must be very accurate for a strong digital signal. I dont have an abundance of local channels, nor am i between different major or regional markets. The db4 is simply the best mid range hdtv antenna on the market.
Dual slot, 330x150x50mm lxwxh water cooling support. Quick start assemblyinstallation instructions antennas. Nov 20, 20 the db4 is simply the best mid range hdtv antenna on the market. The receiving properties of antennas are characterized by the antenna affective area af,t,i, where the available power at the output of the receiving antenna prf is the product of the effective area of the receiving antenna in direction t,i and the flux density swm2hz1 incident from that direction. Antennas direct 4element bowtie tv antenna, 60 miles. The jpole also matches the high impedance at the end of a. When modified by a resourceful radio amateur, theyll becomewith almost no cash outlaya respectably performing yagi antenna for the 2meter band.
We have created an antenna the size of our traditional db4, with the the performance of the db8. That is why you can see i have an old timey rotor in the setup. The vhf signals were not too bad one noticeably weaker than others, but the digital signals are always crystal clear. Antennas direct vhf kit, indoor, attic, outdoor, add vhf capability. Antenna kits accessories radio reconnaissance technologies. It is a halfwave long on the lowest frequency, and is fed from a coax cable through a transformer inserted in the wire at onethird from one end. The channel master 4bay 4221 has slightly higher gain since its continuous screen radiates less out the back.
Ditch cable tv and still get your favorite local news, sports, weather and network tv shows with an hdtv antenna. The more the antenna loops, the better signal receive, but also the bigger the antenna size. After some moderately successful experiments with a homemade db4 antenna i convinced myself that its worth investing in real antennas. Introduction an antenna is an electrical conductor or system of conductors otransmission radiates electromagnetic energy into space oreception collects electromagnetic energy from space in twoway communication, the same. In late 2007 and through much of 2008 the hoverman antenna was subjected to computer modeling and a number of improvements were made by a small group of antenna enthusiasts on the digitalhome. This article discusses the antennas direct db4e hdtv antenna. Antenna characteristics page 3 a 3d power pattern b 2d power pattern in rectilinear format figure 5. Fractal antennas can take on various shapes and forms. Antennas direct extended range uhf hdtv antenna db4e. Antenna fundamentals an antenna is a device for converting electromagnetic radiation in space into electrical currents in conductors or viceversa, depending on whether it is being used for receiving or for transmitting, respectively.
The antenna is easy to assemble and can be roof mounted. Feb 08, 2014 didnt built the antenna, just bought a good poorsignal vhf uhf antenna because, at the time, local stations were still on vhf but planning the change to digital broadcasting on uhf. Fractal magic diy hdtv antenna coaxial cable ultra high. The antenna was assembled and mounted onto an 114x5 ft length of rigid pvc pipe o. A db4 antenna is more like a sweet stop, not too big in size and excellent hdtv receptions. The jpole pattern resembles that of an ideal vertical dipole because of its minimal interaction with the feed line. Oct 18, 2015 schematic diagram of gray hoffman antenna design. You can either get db4 hdtv antenna from the shops or diy it yourself at home using fairly cheap parts. Terrestrial digital db4 terrestrial digital db4 multi. Didnt built the antenna, just bought a good poorsignal vhf uhf antenna because, at the time, local stations were still on vhf but planning the change to digital broadcasting on uhf. Thus, an antenna with a gain of 3 dbd would have a gain of 5.
What is the data file structure used for tap antenna libraries a. Protection plan documents will be delivered via email within 24 hours of. You can use the tap antenna files editor to view, add to or modify antenna patterns in these files or create and edit a new set of antenna files. It will pull in all uhf frequencies and most higherlevel vhf frequencies with a range of about 55 miles.
Power patterns for an arbitrary antenna 2 the maximum sidelobe level sll is often of concern to antenna designers, particularly if the antenna was designed to focus power in a speci c direction, since sidelobes essentially represent a. Connect the antenna to the tv or receiver and run a full channel scan. Starting with hertzs antenna model followed by a short introduction to the fundamentals of wave propagation, the important general characteristics of an antenna and its associated parameters are explained. Antennas direct db4 uhf hdtv antenna db4 solid signal. The hoverman antenna was invented in the 1950s by doyt hoverman before the advent of computer modeling, and appears to be a variation for uhf of the much earlier chireixmesny shortwave antenna. The fractal antenna not only has a large effective length, but the contours of its shape can generate a capacitance or inductance that can help to match the antenna to the circuit. 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. Go to view and scroll down to read out loud and activate. That assumption proved to be correct as i have received letters from a wide variety of people. But it is only a small fraction of all the files i have produced. Aston martin db4 windshield repair kit manual, us history chapter 18 section. On several web forums one of the leading contributors to antenna design and computer modelling is a guy from delaware, usa with the user name 300ohm who has done a huge amount of work on the gray hoverman, and i also mentioned j3d, who has also done crucial design work on the gray hoverman antennas on his own free time.
This horizontally polarized antenna is an extension of the horizontal loop antenna featured in the arrl antenna book. Getting the mounted antenna through the 18x50 opening, unassisted, was awkward. Functioning as a trigger diode with a fixed voltage reference, the db3db4 series can be used in conjunction with triacs for simplified gate control circuits or as a. Aston martin db4 windshield repair kit manual, us history chapter 18 section 1 guided. Unless stated otherwise, all performance data computed using remcom, inc. For example, a quarter wavelength monopole can be transformed into a similarly shorter antenna by the koch. Apr 17, 2016 the more the antenna loops, the better signal receive, but also the bigger the antenna size. Isotropic antenna idealized oradiates power equally in all directions dipole antennas ohalfwave dipole antenna or hertz antenna oquarterwave vertical antenna or marconi antenna parabolic reflective antenna oused for terrestrial microwave and satellite applications olarger the diameter, the more tightly directional is the beam. Antennas direct extended range uhf hdtv antenna db4e watch tv for free with the easy to install antennas direct db4e and stop paying so much for cable. Antennas direct extended range uhf hdtv antenna db4e from. It was designed to be an outdoor hd antenna but because of its. I built this bowtie style antenna in about an hour and cant believe the way it. Antenna basics white paper this white paper describes the basic functionality of antennas. I have an older analog crt tv and needed a new digital antenna to go with my new converter box.
It seems that there is less and less on cable than there ever was. I dont have an abundance of local channels, nor am i. Another nice feature of decibels is they make multiplication problems become addition, as seen on the decibel math page. But only a professional can select and precisely install the correct antenna and assure his customers years of superior tvfm reception. Antennas direct long range outdoor dtv antennadb4e the. The performance of this jpole is, theoretically at least, equal to a. They confirmed that the types of people who buy the book meet the profile above. If you are looking for an antenna that is practically guaranteed to perform, the db4 is one of your safest choices. Cornerreflector antennas light bar mounted on the roof ahead of the antenna. Antennas direct db4 multi directional hdtv antenna. It took me about 15 minutes to assemble the db4 antenna and then attached it to the jmount.
The ocf fd4 fd3 windom antenna fd4 80402010 m the 4band fritzel model fd4 is a special version of a windom antenna. A db8 antenna has 8 receiving elements, or 4 pairs of elements. Quick start assemblyinstallation instructions antennas direct db4e before attaching the antenna to any surface, test reception in that area. Here is a small collection of eznec files of antennas i have interest in. I try to simulate every antenna i get in my fingers. The db4 hdtv antenna is recognized by hdtv primer as the highest performing indoor antenna. We have created an antenna the size of our traditional db4, with the the.
What truly sets the da2 apart from other sff cases is its unique approach to mounting components. It utilizes a rail and bracket system that makes it incredibly. If you are within 3040 miles of your tv stations, then this is the antenna for you. The db4 was easy to assemble, and i purchased the 75 cm jmountmast by antennas direct as a companion mount for the exterior installation. Antenna gain relative to a dipole antenna can be expressed in decibels as dbd. It was with surprise and delight that i noted that clerks in one radio. How to build a db4 antenna moneyrhythm tv antenna, hd. Clerks in radio stores told me that this book was outselling other titles 2.
Range is rated up to 65 miles, making it ideal for those in locations that can pull long range signals from various directions. The antennas direct db4e ultra long range indooroutdoor hdtv antenna has 3x the power and half the size. What follows is my foray into the world of hdtv antenna construction and trying to squeak the most out of it for a moderately fringe tv area i live in. If reception is not as desired, move the antenna and rescan tvreceiver. Terrestrial digital db4 multidirectional hdtv antenna the db4 is simply the best mid range hdtv antenna on the market. The tap antenna files are used by the tap antenna lookup program to select a directional antenna and its associated horizontal and vertical patterns used by a tap field strength calculation program. Back in the 1940s, tv antennas were actually manufactured by hand at the installation site. The db4e ultralongrange atticoutdoor multidirectional hdtv antenna is. It is able to pick signals at a 40 mile range and is ideal even for areas with a hilly terrain or on a valley.
A mobile antenna horizontalplane pattern figure 12. Average gain dbd bw 3 db manufacter model typereflector band boom uhf averages cm chan. No other bow tie antenna can match the db4es combination of power, gain and value. The da2 is a compact itx case designed to strike a balance between size and compatibility, allowing for highperformance components to fit comfortably in a small form factor space. Get hdtv over the air for free with a powerful antenna. This page is part of an hdtv primer, which starts at. Next antenna build a better diy model db4 antennas. Antennas direct doubles the power of traditional bow tie designs. The success of the three previous editions of practical antenna handbook has been most gratifying.
The antennas direct db4 multidirectional hdtv antenna is ideally suited to pull long range signals from various directions and it is the most suitable alternative to a rotating antenna. I found it was quite impossible to use a rotor without an indicator when positioning for a certain station. Nov 12, 2010 the db4 is simply the best mid range hdtv antenna on the market. Antennas direct db4 uhf hdtv antenna db4 replaced with xtreme signal antenna hdb4x with an approximate. In late 2007 and through much of 2008 the hoverman antenna was subjected to computer modeling and a number of improvements were made by a small group. It was designed to be an outdoor hd antenna but because of its small size, it can conveniently be used indoors as well.347 131 1005 1543 1104 941 216 1007 1177 536 187 684 1050 529 592 841 801 712 158 1080 1040 913 487 221 698 28 867 810 1453 280 1050 69 759 1422 623 1249 203 31 1450 299 71 334 1021 150 246