- How many radials do I need for a vertical antenna?
- What is an antenna counterpoise?
- What is the best metal for antenna?
- What is one disadvantage of a random wire antenna?
- Are end fed antennas any good?
- How long is a long wire antenna?
- Can an antenna be too long?
- What determines antenna impedance?
- How do you test for UnUn?
- How long should my counterpoise be?
- Does the size of an antenna matter?
- What does a dipole antenna do?
- Is the g5rv a good antenna?
- Does a half wave antenna need a ground plane?
- How do I reduce my tower footing resistance?
- What is the feed point impedance of an end fed half wave antenna?
- Does a dipole antenna have to be straight?
- Does a long wire antenna have to be straight?
How many radials do I need for a vertical antenna?
A proper ground system for a quarter wave or similar vertical antenna is about 120 radials, evenly fanned out from the base of the antenna, each a bit longer than 1/4 wavelength (.
What is an antenna counterpoise?
In electronics and radio communication a counterpoise is a network of suspended horizontal wires or cables (or a metal screen), used as a substitute for an earth (ground) connection in a radio antenna system.
What is the best metal for antenna?
CopperCopper is a best suited material for base antennas. The metal, while soft and malleable, is quite rigid. Stainless steel has a higher tensile strength, so thinner wire can be used. This makes steel an excellent choice for mobile whip antennas where flexibility is a must.
What is one disadvantage of a random wire antenna?
One disadvantage of a directly fed random-wire antenna is that you may experience RF burns when touching metal objects in your station. The simple single wire length of the random-wire antenna acts as both feed line and antenna and is directly connected to the transmitter.
Are end fed antennas any good?
While dipoles are very efficient antennas, they are not the only way to go. Some houses don’t really lend themselves to installing a half-wave dipole. If you only have one support an end-fed antenna may suit you better. But be warned – end-fed antennas can be noisier and also cause more EMC/interference problems.
How long is a long wire antenna?
You also want the antenna to be at least 1/4 wavelength long for each band you plan to use. For instance, to work 40m be sure the antenna is at least 10m or 33′ long….Wire Lengths for Various Band Combinations.GroupUSA Bandsd80-40-30-20-17-15-12-10e160-80-40-30-20-17-15-12-10f160-80-60-40-30-20-17-15-12-10-63 more rows
Can an antenna be too long?
Member. Depends on your environment. If you have any local transmitters on the AM band, then they can overload the early stages of your radio if your antenna is too long. You will hear the stations even though you’re not tuned to them!
What determines antenna impedance?
The electric current will then be equal to: Hence, antenna impedance is a simple concept. Impedance relates the voltage and current at the input to the antenna. The real part of the antenna impedance represents power that is either radiated away or absorbed within the antenna.
How do you test for UnUn?
You want to test the UnUn so one easy way to do that is to place a 450 non inductive resistor across the output of the UnUn and an antenna analyzer to the input. Now sweep the UnUn.
How long should my counterpoise be?
30-40 feetLength of counterpoise should be a minimum of 30-40 feet but not the same length of the antenna wire. Shorter length counterpoise wires can be used if operation is confined to 40m or higher. Any counterpoise should be at least 1 foot above ground running away from or perpendicular to the antenna wire.
Does the size of an 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.
What does a dipole antenna do?
Dipole antennas (or such designs derived from them, including the monopole) are used to feed more elaborate directional antennas such as a horn antenna, parabolic reflector, or corner reflector. Engineers analyze vertical (or other monopole) antennas on the basis of dipole antennas of which they are one half.
Is the g5rv a good antenna?
Based on models and air testing the G5RV performs quite well as a 5-band antenna. Those bands include 80, 40, 20, 15, and 12 meters. The antenna will NOT work as well as a dipole on any other HF band. By adding a relay and a ground system the G5RV can be made to work quite well as a “T” antenna on 160 meters.
Does a half wave antenna need a ground plane?
Member. A half-wave dipole (horizontally installed) doesn’t need any ground plane or counterpoise. As for other variations on the “half wave” theme, try it with and without.
How do I reduce my tower footing resistance?
When the tower footing resistance exceeds the design values,modification of the existing installation should be considered. The techniques to achieve this are a combination of the following:counterpoise earthing,vertically driven copper rod electrodes,and conductive concrete and copper-coated steel earth electrodes.
What is the feed point impedance of an end fed half wave antenna?
1800 to 5000 ohmsIn practice the impedance at the end of an end fed half wavelength antenna is on the order of 1800 to 5000 ohms. It is often commented that the End Fed Half Wavelength Antenna needs no “counterpoise” or radials to work.
Does a dipole antenna have to be straight?
Dipole antennas need not be installed in a horizontal straight line. They are generally tolerant of bending, sloping or drooping as required by the antenna site. Remember, however, that dipole antennas are RF conductors.
Does a long wire antenna have to be straight?
The easiest to put up and simplest to build antenna is the longwire. This is a length of wire that is run from your receiver to a point as far from the radio as possible. … Do not worry about keeping the wire straight across the room. Going around is fine and will not harm reception.