What length is 5/8 wave 2 meter antenna?
48.2″
2 METER 5/8 WAVE ANTENNA
This 5/8 wave (physical & electrical) antenna has a nominal impedance of 50-52 ohms and can achieve average tuned SWR of 1.5 to 1 over 4 MHz. The over all length is 48.2″ (122.4cm).
How long should a 2m antenna be?
The higher the frequency, the shorter the wavelength. Most commercially available antennas come in length equivalent from 1/4 to 5/8’s of a full wavelength. This means that if you want to run a 2m rig (144’ish Mhz),a half wavelength antenna would be 3.3” long, and 3.3 ft is very manageable for vehiclular operations.
What is the formula to calculate antenna length?
The Half-Wave Dipole Antenna
The most widely used formula to calculate the approximate overall length of wire required for a dipole is: 468 / frequency (MHz) = length of wire in feet.
What is the gain of a 5’8 wave antenna?
5λ/8 vertical antenna gain
In an ideal world, it is found that a five eighths wavelength vertical antenna could exhibit a gain of close to 4 dBd, i.e. 4 dB gain over a quarter wave vertical.
What is the difference between 1/4 wave and 5/8 wave antenna?
In the real world the actual gain difference between a 1/4 wave antenna and a 5/8th wave can be anywhere from no gain or a very slight loss up to a maximum of 2dB gain over a 1/4 wave. The 5/8th wave is never really worse, explaining why people have no problems using them. This is true for any repeater antenna height.
How does a vertical antenna work?
Multiband verticals use several traps or similar circuits to electrically change the length of the antenna according to the frequency of the transmitted signal. (The traps are in the vertical elements, not the radials.) Vertical antennas take little horizontal space, but they can be quite tall.
What is the optimal length of an antenna?
The most effective antenna has the same length as the length of the wave it is used for. For practical purposes, half or a quarter of that length will suffice. Most LoRa antennas are a 1/4 wavelength.
What is the correct length of an antenna?
The corresponding optimal antenna length should be 0.69/4, which is equal to 0.1725 meters. The above is the relationship between the length of the antenna and the frequency and wavelength. The length of the antenna is directly related to the wavelength of the working frequency.
What is antenna formula?
Antenna Factor (or correction factor) is defined as the ratio of the incident Electromagnetic Field to the output voltage from the antenna and the output connector. Gain (dBi) The ratio of the signal received or transmitted by a given antenna as compared to an isotropic or dipole antenna.
How big should my ground plane be?
A solid ground plane will work, and it should be a quarter wave radius. For FM Radio, wavelength is about 3 m, so the ground plane should be 1.5 metres in diameter.
How long is a full wave CB antenna?
39.34 feet long
The CB portion of the spectrum begins at 25.01 megahertz, so a full wavelength antenna would be a bit more than 39.34 feet long. That’s obviously a little long to attach to your bumper, so people tend to use antennas that are a fraction of the wavelength: 1/2, 5/8, 1/4 and 1/8 are all common wavelengths for antennas.
Does a 1/4 wave antenna need a ground plane?
Does a 1/4 wave antenna need a ground plane? Answer: Yes. All 1/4 wave antennas work best if they are installed in the center of a metal ground plane with at least 1/4 wave length radius (1/2 wave length diameter: ~6 inches for 900Mhz and ~3 inches for 2.4Ghz); larger is better.
How high should a vertical antenna be mounted?
A height of 120 feet or even higher will provide even more advantages for long-distance communications. To a distant receiving station, a transmitting antenna at 120 feet will provide the effect of approximately 8 to 10 times more transmitting power than the same antenna at 35 feet.
How many radials do I need for vertical antenna?
Butternut recommends a minimum of 30-60 radials at 65 feet each. Hy-Gain suggests numbers based on a chart similar to Table 1 below. It’s obvious there isn’t a consensus among vertical antenna makers. If you need a number to start, twenty 32-foot radials will give you a workable system with most vertical antennas.
Is longer antenna better?
Longer antennas have lower frequencies and higher bandwidths. This means signals can travel over longer distances. Radio stations operate at lower frequencies and their signals can easily connect to longer antennas.
Can an antenna be too big?
A bigger antenna, properly designed, will always have more gain than a smaller one. And it will be the best kind of gain, much better than using a small antenna and simply overamplifying it, because a small antenna just won’t pull in truly weak signals like this gigantic one will.
Does length of antenna matter?
So the answer is yes, size does matter, but bigger isn’t always better. It all depends on what your transmitting and receiving frequencies are. Theoretically, a longer antenna will have a greater range, but it is far more important for optimal radio performance that the length of the antenna matches the frequency.
How do I know the range of my antenna?
To calculate the range of an antenna, you multiply the square root of the antenna’s height above water (in feet) by 1.42. The product will equal the antenna’s communication range in miles.
Is higher antenna gain better?
On an open and flat highway, a high gain antenna will be better… 3 dB, 6 dB, etc. If your desired coverage area is hilly then a ¼ wave omnidirectional antenna will be better. The other type of gain is directional and is important for base stations.
Can a ground plane be too big?
According to this guidance from Pulse Electronics, makers of Larsen amateur antennas, the only limitation on the “ground plane” is that it exceed a minimum size: Ground plane availability is [a] critical factor in mobile antenna performance …
How do you tell if an antenna needs a ground plane?
If you have a fiberglass vehicle or boat you will need a No Ground Plane Antenna. In No Ground Plane systems, the coax shield is used for counterpoise (substitute for the ground connection).
What is an advantage of using a properly mounted 5/8 wavelength antenna?
A properly mounted 5/8 wavelength antenna for VHF or UHF mobile service offers a lower angle of radiation and more gain than a 1/4 wavelength antenna and usually provides improved coverage. An antenna that concentrates signals in one direction is a beam antenna. The quad, Yagi, and dish are directional antennas.
Is a half wave antenna better than a quarter wave?
For RF applications, 1/2 wave antenna will be more suitable compared to 1/2 wave antenna due to following reasons: No Ground plane is required for 1/2 wave antenna while its required for 1/4 wave antenna. More energy will be transmitted horizontally in 1/2 wave antenna compared to 1/4 wave antenna.
Is it effective if rather antennas are mounted on higher ground Why?
As a very general rule of thumb, the higher an HF antenna can be placed above ground, the farther it will provide effective communications because of the resulting lower radiation angle. This is true for any horizontal antenna over real as well as theoretically perfect ground.
Does antenna length affect reception?
The higher the frequency and the shorter the wavelength, the shorter the antenna can be made. When the length of the antenna is 1/4 of the wavelength, the transmission and reception conversion efficiency of the antenna is the highest.