What is the length of the antenna?
Antenna lengths for popular ham radio bands
| Approximate Lengths for Ham Band Dipole Antennas | ||
|---|---|---|
| Band (MHz) | Length (feet) | Length (metres) |
| 3.5 | 137 | 42.2 |
| 7.0 | 68.5 | 21.1 |
| 10.1 | 47.5 | 14.7 |
Can an antenna be any length?
In general yes, it can be any “reasonable” length (e.g. not infinite). The principle of antenna is based on Electrical resonance , the efficiency depends (beside other factors) on the Electrical length of the antenna and the frequency of the signal (and tons of other factors) – See Resonance .
Why should length of antenna depends on wavelength?
This frequency is determined by the length of the antenna and the speed of light in the antenna material. In this resonant condition, the electrons’ motion and the incoming electric field are always in the same direction, so every wavelength of the EM wave builds up more motion and puts more energy into the antenna.
How do you determine the height of an antenna?
The coverage can be calculated as 4.4 times the SQUARE ROOT OF THE height of the antenna . For example an RX antenna at 60 meters height has a estimated coverge radius of 4.4 x sqrt 60= 34 Km . This is in ideal conditions and with the power of mobile and sensitivity of receiver to guarantee the link.
HOW FAR CAN 2.4 GHZ transmitter work?
A frequently asked question about the WirelessHART 2.4GHz radio network is “How far can these devices transmit?” Depending on local units of measurement, the rule of thumb distance for the standard antenna is 225 meters or 750 feet.
What factors determine antenna gain?
Antenna gain indicates how strong a signal an antenna can send or receive in a specified direction. Gain is calculated by comparing the measured power transmitted or received by the antenna in a specific direction to the power transmitted or received by a hypothetical ideal antenna in the same situation.
Can an antenna be too high?
In general, the higher you place your antenna, the better. It would be best to have your antenna placed 30 feet above ground level to give you the clearest over-the-air connection with a tower. In general, you’ll want an amplified antenna if you’re 30 or more miles away from your local broadcast tower.
How is height of antenna related to modulation?
Reduction in the height of antenna For the transmission of radio signals, the antenna height must be multiple of λ/4 ,where λ is the wavelength . Thus, modulation reduces the height of the antenna .
How do you calculate the length of an antenna?
Divide the optimum antenna length by two if you are using a dipole antenna, which simply means “two poles.”. The result is the optimum length for each of the two poles. (Alternatively, just divide 234 by the frequency.)
What is the formula for antenna length?
The formula for calculating antenna length in feet is 468/f, where f is the center frequency. The FM band runs from 88 to 108 MHz, and dipole antennas amplify a center frequency with the amplification factor decreasing on either side of the center frequency.
What is the ideal CB antenna length?
The higher the antenna goes, the farther your message will go, and you can receive messages from farther away. The ideal length antenna for CB radios is 102 inches (about 8 and ½ feet!) because it is equal to ¼ of a wavelength. Obviously, this isn’t even an option for most people.
In general yes, it can be any “reasonable” length (e.g. not infinite). The principle of antenna is based on Electrical resonance, the efficiency depends (beside other factors) on the Electrical length of the antenna and the frequency of the signal (and tons of other factors) – See Resonance.