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A transmitter antenna is a tuned circuit and it can be very complex and it even get more difficult at higher frequencies, if it's not a 1/4 wave length of the transmitter frequency it is un tuned and you will have some of your RF power radiated back to the transmitter, that is called SWR, for Standing Wave Ratio and it will damp the RF that is radiated from the antenna and if the SWR is to high it can damage the transmitters final stage. It don't have to be the real physical 1/4 or 1/2 wave and it can even be 5/8 of the wavelength but then a L/C circuit have to be inserted at the input side of the antenna to tune the antenna to the correct frequency one antenna can even be used for two different frequencies, then a L/C tuning circuit have to inserted at a 1/4 wave length of the higher frequency , this type of antenna is used in duplex systems, like a cell phone.
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What is the Difference between the crest and trough?
wave height. -- The highest point of a wave is known as its crest while the trough is the lowest point of the wave. Wavelength is the horizontal distance between successive crests or troughs. by: Claire O.
What is the need for antennas what are transmitting antennas what are receiving antennas?
Antennas transfer energy from a cable into the airwaves efficiently. Any transmit antenna can also be a receive antenna and viceversa. If you wish to transmit high power from an antenna, usually heat generation or high voltage is a concern that can destroy the antenna. To prevent problems, high power antennas require thicker wires and sometimes insulators to prevent overheating/burning and arcing. Many antennas can simply be made of wire of a simple length and they'll be very efficient. The length of an antenna changes it's efficiency to the cable. If you want the antenna to be efficient, you must size it to match the cable impedance. Usually the length of a single wire exiting above a metal plate is one quarter wavelength or 1/4 x 11,803/frequency in megahertz. For FM radio on an automobile, some antennas have motors that extend out of the body of the car. The height (inches) should be 1/4 x 11,803/100 megahertz or just under 30 inches. TV antennas above a house are most often a set of half wavelength wires, so change the 1/4 to 1/2 in the formula above. They use many different wire lengths to cover all the frequencies in the television band, which extends from about 50 megahertz to around 600 megahertz. Cell phone frequencies were picked partly to make the antennas small and partly so that cell phone reception can enter buildings with rebar reinforcement. Cell phone frequencies are roughly 800 megahertz and 1800 megahertz. Receiver antennas are often made smaller than either transmit or transceiver antennas. If you open up the back of an older transistor radio, you are likely to find a bar made of ferrite material with an insulator and wire wrapped around that. The wire is wrapped a number of turns to match the impedance required by the circuit. The ferrite bar is able to focus signals to itself which in turn induces a current in the coil. While impedance is an important issue, simple dipole antennas can be sized by the 468/Frequency in mHz formula. It will give the the length of an antenna in feet. You divide the outcome by 2 to find out what each side length should be. The impedance of an antenna can ofter be adjusted by its shape. The 90 degree V shape yields a near perfect 50 ohms impedance which is commonly used for transmitters and transceivers where as the flat top diode has a higher impedance. The ARRL has good books on antennas. You might want to go to the library and look at a few of them.
What is the effect of height on settling rate?
an increase in height increases the length
Average chair height?
The average height of a chair is between 16 to 18 inches for adults. This is found to be the most comfortable height for a seat.
What is standard height of a laboratory counter?
Should be the same as a standard counter height, 36".
What is the relationship between frequency and antenna height?
For horizontal antennas operating below 30 MHz the optimum height is half a wavelength, so the height in metres would be 149.9/Frequency in MHz.
What is the height of a wavelength?
That is the amplitude.
What is the height of a quarter?
The current height of an U.S. quarter is 1/16th of an inch.
How you find an height of antenna cb?
trigonometry
Write a short note on antenna effective height?
Antenna effective height is a measure of an antenna's efficiency in converting electromagnetic waves into electrical signals and vice versa. It represents the equivalent height of a theoretical vertical antenna that would produce the same signal strength. The effective height considers factors such as antenna design, orientation, and the surrounding environment to provide a standardized measure for comparison among different antennas.
How tall is the antenna on the Empire State Building?
The height of the Empire State Building's antenna is 204 feet.
What are the example of variables?
Height, weight, wavelength of light.
Is the ratio of height to wavelength the same for both waves?
No, the ratio of height to wavelength differs for different waves. The height of a wave is the distance between its crest or trough and the rest position, while the wavelength is the distance between two consecutive crests or troughs. These characteristics vary depending on the type of wave.
What happens when the ball is served above the height of the antenna in volleyball?
Nothing, the ball is still in, unless the ball hits the antenna. If the ball hits the antenna at any point. The ball is called out.
What are the example of continuous variable?
Height, weight, wavelength of light.
Is The wavelength of a wave measures the height of each crest?
No. The wavelength is the distance, or separation, between each crest.
How do the wavelength and wave height change as a wave enters shallow water?
As a wave enters shallow water, the wavelength decreases while the wave height increases. This happens because the wave encounters the ocean floor, causing the wave to slow down and compress, resulting in a shorter wavelength and higher wave height.
