0
Yagi antennas may be purchased online through sites such as Amazon or eBay. Alternatively, someone may wish to buy an antenna directly from the manufacturer. If one wishes to buy from the manufacturer, ZDA Communications, one should call 803-608-4122, send a fax to 803-736-5310, or send a letter to 100-3 Forum Drive Suite 192 Columbia, SC 29229.
What else can I help you with?
What is a Yagi-Uda antenna?
how to measure the length of elements and spacing of elements
What is a Yagi antenna?
A yagi is a directional antenna consisting of two or more dipoles.
How does yagi-uda antenna differ from a folded dipole a loop antenna and a helical antenna?
Wow, your question on how a yagi-uda differs from a folded dipole, a loop antenna, and a helical antenna relates very much to how does a lawn mower engine relate to a V-8. The principals in all the antennas remains much the same. So I will deal with them in the order asked. The Yagi in its simplest form consists of 3 elements. The center element is the driven element and is essentially a dipole. Behind it is a slightly larger element called a reflector which does just that, it reflects signals to and from the dipole and in front there is the smaller director which helps focus energy. This is a directional antenna with gain. The folded dipole goes back to the basic dipole except it has makes a full loop. They are just as about as long as regular dipoles. With the loop of wire out there, they tend to have a wider band width than regular dipoles - but are not as tolerant of being used at even multiples of their cut frequency as the wires tend to cancel out each other. Oh, btw, yagi's have been made using folded dipoles. You must use ladder line or a 4:1 balun on folded dipoles, with perhaps the exception of the terminated folded dipole which has a resistor where the two elements of the dipole come together. The loop antenna? Which loop? I assume you are talking the traditional loop and not the magnetic loop. The full loop is normally computed to be 1005/frequency=feet. While you could take the time to tune the antenna, it might just be easier to put in a balun and an antenna tuner. The main advantage of a loop over the previous reviewed antennas is that it does fairly well even though fairly close to the ground where the previous 2 antennas should be at least 1/2 a wave length up for good performance. Helical antennas are generally good for just one band. In fact, due to the loading they cause they are best if used on a single frequency as their feed line requires them to be provided the connecting feed the is the electrical equivalent of a 1/2 wave at that frequency of operation. This may work well at VHF and above as an entire band can be tuned satisfactory, but in HF it would limit you to a very small segment of the band. Helical antennas definitely are the lawn mower engines of the antenna world. Look up antenna elmer on your favorite search engine. You have entered into a world where there is still a lot homework left to be done.
What two types antenna used for terrestrial microwave communication?
Virtually all terrestrial microwave communication is point-to-point, using parabolic reflector antennas. A small percentage uses yagi, helical, corner reflector, or flat-plate reflector antennas. Essentially no "omnidirectional" antennas are used in microwave.
Up to which frequency does the gain of an antenna increase as the frequency increases?
In general, an antenna is "cut" or "built" for one frequency, or for a band of frequencies centering on one particular frequency. This antenna will respond to all frequencies, but will only exhibit "maximum" gain at one frequency. Frequencies higher or lower will not be received quite as well, and the farther from the "tuned" or "center" frequency the signal is, the less gain the antenna will provide on that frequency. As we work with an omnidirectional antenna, we can "tinker" with it a bit in an attempt to get it to work with a broader range of frequencies, but as we broaden the usable spectrum over which it will work, we will see less gain on the "center" frequency. If you're getting the idea that tuning an antenna involves trade-offs, you're getting the right picture. No improvements are possible without "cost" in another part of the operating spectrum. If we move to a directional TV antenna like, say, one of those antennas (not the dish) that still can be seen on some rooftops, we see what is basically a modified log periodic antenna. This antenna will generally be "pointed" or "aimed" in the general direction of the transmission antenna of the station(s) for which reception is desired. Stations with broadcast antennas to the side or the rear of this antenna won't be "seen" as the antenna is highly directional. Having said all that to get you up to speed on some fundamental concepts of the antenna, as we move up the frequency spectrum (starting "low"), the gain of the antenna will increase until we reach the "center" or the "tuned" frequency for that antenna. After that, increasing the frequency will result in signals with increasingly lower gain.
What is a Yagi-Uda antenna?
how to measure the length of elements and spacing of elements
What is a Yagi antenna?
A yagi is a directional antenna consisting of two or more dipoles.
Is a Yagi antenna a directional antenna?
Yes.
What is better a yagi antenna or directional antenna?
A yogi is a directional antenna.
What is a yagi?
A yagi is a directional antenna consisting of two or more dipoles.
Who discovered the antenna?
yagi uda
Why yagi uda antenna is used?
Some advantages of the Yagi- Uda Antenna include that this is a widely used design and low cost. The construction also is simple. Some disadvantages are that the receiver of the Yagi-Uda Antenna may have problem receiving signal.
What are the disadvantage of yagi-uda antenna?
bandwidth is less..
How many directors and reflectors in Yagi Uda antenna?
yagi udda antenna has only one reflector...but it has many directors...depending upon gain and efficiency...the length of reflector is normally...more than one-half of wavelength... and directors have a length less than one-half of wavelength...
Is yagi uda antenna have parasitic elements?
Yes, the Yagi-Uda antenna has several parasitic elements, in the form of a reflector ("behind" the driven element) and the directional elements ("in front" of the driven element).
What is the gain of yagi antenna?
Typically, +10db, but other configurations are possible.
What is yogi antenna?
It is a Yagi antenna- used for TV reception. nothing to do with either Yoga or yogi bear or Berra!
