- For slots that are made to be intentional antennas, they are usually slots in a waveguide or a box. Of course this changes the radiation pattern and the impedance, and the feed is not a voltage source directly across the sides but provided by the currents in the waveguide, but the basic mechanism of how they work remains the same.
- The slot antenna, consisting of a narrow slit in a ground plane, is a very versatile antenna. With modification, it is amenable to waveguide, coplanar waveguide (CPW), coaxial, slot line, or microstrip feeding schemes and has been used in all aspects of wireless and radar applications.
The best time to put down radial wires for your amateur radio setup is early spring but it can be done other times as well. I have even done it in the fall and had good success.
The idea behind installing radial wires without digging is to let your grassy lawn grow over the radials and protect them from the mower. You don't have to trench or bury them!
Finally, starting from the antenna end of the radial wires and about every three-to-four feet, hold the wire down with a radial wire staple while pulling the radial out from the antenna to keep it taut. Push it in as far as possible to get the wire as close to the grass roots as possible. I typically use a hammer or rubber mallet to drive it home.
First, mow the grass pretty short in the areas where you will be laying the radial wires down. Notice, I didn't say 'scalp' it—just lower the mower until the grass is about one-inch long after cutting. (Remember to readjust the height of the mower back to normal before you put it away).
Next, connect the radial wires to the radial plate with wire terminal ends and stretch them out while arraying them evenly around the antenna (that's what 'radial' means).
Radial Wires Attached to the Radial Plate
Note: Red wires were used so they can be seen in the pictures. DX Engineering Radial Wire has a Black relaxed PVC insulation.
Some AM broadcast engineers might tell you that the radials should be as long as you can make them - up to about 1/2 wavelength. However, if you can only do 1/4-wave or 1/8-wave in certain directions then do it and don't worry about it. They won't be resonant since they are lying on (or in) the ground. You will be surprised how much better your vertical will work. After you install a few radials and see how much better you antenna performs you will have an urge to put in more of them. Remember, laying them on the ground (or burying them) detunes them, so electrical length is relatively unimportant. Don't resist - more is better.
A radial line slot antenna (CP-RLSA) is a slotted waveguide planar array for DBS reception. A number of designs have been devised, but these designs have pros and cons. In order to suppress grating lobes and increase the gain, this article will introduce a new wave material =1.06, arrange the angle and modify configurations of the slot sets. Both patterns are obtained with different excitations of the radial line slot antenna (RLSA). Basically, if the slots are placed in concentric rings, when the RLSA is excited in the centre, a conical or difference beam is generated. However, if a rotating mode is excited, a pencil or sum beam is generated.
Radial Line Slot Antenna Plasma
Finally, starting from the antenna end of the radial wires and about every three-to-four feet, hold the wire down with a radial wire staple while pulling the radial out from the antenna to keep it taut. Push it in as far as possible to get the wire as close to the grass roots as possible. I typically use a hammer or rubber mallet to drive it home. If a radial wire is sticking up any place due to uneven ground or the wire is loose just put another anchor pin there. The idea is to get all parts of the wire down as close as possible to the ground so that the grass can grow over it.
Radial Wires held in place with Staples
Here are some pictures of what it should look like.
Radial Line Slot Antenna Calculator
Two examples of radial wires installed
Antenna Ground Radials
When you finish the last radial wire, your job is done. Mother Nature will do the rest. If you have done this in the early spring, the grass will grow up and surround the wires. The root system will also pull the radial wires down firmly along their full length. Galaxy s6 lite. If you do it in the fall after the grass has stopped growing, it will happen the next spring. This will be done so completely that in a few weeks you will have to actively look for the radial wires to see them. Your mower will miss them completely, too. But you and your contacts will hear them right away!
73,
Paul, NO8D
