Selection Guide for Ground Wave Antennas

1. Horizontal dipole antenna with half wavelength (dipole antenna), also known as antenna DP

It is equal to two lengths, the total length of the half wavelength of the horizontal driver or inclined installation to a half wave dipole antenna. This is a modification from a simple, basic, and simple HAM friend's antenna, and another variation of this antenna is the antenna. The total length of the antenna is approximately half of the required center frequency wavelength at 94%. Based on 96%, the actual effect is slightly adjusted by Barron, and a balanced unbalanced converter with a 1:1 ratio of 95% of the 1/4 wavelength of the two transducers will be matched with the connector. Normally, the maximum tolerable radiation power can be large, such as 500W to 1000W. The radiation pattern of the antenna is a symmetrical tangent point, which is the feeding point of two circles.

Because the horizontal polarization wave of this antenna is absorbed by an electric field to generate a greater impact on the horizontal polarization wave, it is not suitable for short communication. However, due to the transmission of low-level sky waves, it is suitable for communication DX. In common forms of this antenna, in addition to the installation level, there is an inverted V (V n) upright, with an angle of 110 to 120 degrees between the antennas, changing the transmission height, distance, and communication close to the coordinates (DP depicts the installation scheme of inverted V antenna). This antenna is also designed to shorten the geometric shape of the antenna and is easy to assemble, and to install the antenna, commonly known as a trap inductance, but this will lead to a decrease in antenna efficiency to some extent. This type of antenna is sometimes installed in multiple transducers to achieve multi band communication, and the antenna of the balanced unbalanced converter is operated in multiple bands. Common manufacturers such as Diamonds, Eagles, and others sell ready-made DP antennas online, and many fans have also proposed selling such antennas, which can have better communication effects.

2. Antenna vertical monopole (vertical antenna), also known as GP antenna

This antenna is a deformable antenna, which is connected to a dipole antenna at the bottom through an internal conductor feed line, a power line network, and a grounded external conductor. The horizontal direction of radiation is a circle, and therefore suitable for omnidirectional reception with the same activation function. Mobile handheld devices are used for this type of antenna in most frequency bands, and sometimes short-wave communication antennas also use this form of DX antenna.

In the absence of a good ground network system and a large land gateway, the efficiency of vertical antennas is difficult to exceed 50%, especially for vertical antennas with wavelengths less than 1/4. In order to shorten the geometric shape of a vertical antenna, it is usually applied to the number of antennas, but achieving this at the cost of antenna efficiency is the theoretical maximum efficiency added at the top of the antenna. The GP antenna segment U/V portable device greatly enhances the overall feel of the segment. The GP shortwave implementation of some antenna devices is generally achieved by incorporating devices that are primarily sensitive to mechanical strength considerations. The vertical monopole of the antenna absorbs radio waves in all directions due to the radiation angle in all directions. Therefore, in some cases, the electromagnetic environment is not ideal, which can easily lead to high noise. The HAM part is a regular U/V antenna with a vertical fiberglass antenna, especially due to the metal tube covered by the exterior paper and weather resistant external antenna with a fiberglass shell. The metal/V section of the U vertical antenna material is also convenient and practical for installation on the vehicle. Ordinary U/V vertical antenna, do you have diamonds, eagles, etc. Huahong is now easy to purchase through the internet.

(Used for car antenna ultraviolet image, commonly known as switch)

Common shortwave vertical antennas are used, and, like Diamond, MFJ, Huahong and other manufacturers, the main diamond shortwave antenna vehicles are shortened. The focus of MFJ shortwave base stations is mainly on using vertical antennas with a length of 1/4 of the wave.

3. The Winton antenna (antenna window), also known as the half wave antenna feed section, is mostly made from a single wire feed device with a deviation of 14% from the center of the location, and is generally used as a receiving antenna without transmitting the antenna. The Tongtai antenna, due to its small share in small areas, eliminates the small usage space of HAM rooftops and is also suitable for portable use in the communication field. On the internet, there are also many sellers selling well crafted Tongtai antennas.

4. Yagi antenna (Yagi antenna)

In 1925, "Yagi" was invented by the then Minister of Tohoku University, Shintaro Yuda of Yagi. Yagi is spelled in English and consists of multiple units, with strong directionality, higher gain, and rotatability. It is usually used in conjunction with it to achieve the desired 360 degree communication of the communication object.

(Image antenna 430-440MHz handheld Yagi)

Yagi antennas can operate in several bands, and some can communicate in shortwave in four bands. There are also sections with U or V Yagi antenna sections, mainly used for direction detection in FMDX communication or radio and satellite communication. Aiming at Yagi antenna height, it has also undergone a series of AMH, standing on a huge tower and antenna. There are also many amateur radio competitions in China and foreign countries, and Yagi antenna's professional performance has led to many times achieving good communication results. (Image of foreign HAM's great seaside with built-in Yagi antenna)

5. Antenna block (four antennas)

In the 1940s, the W9LZX (Clarence Moore) in Quito, Ecuador, invented a communication antenna with good performance. The antenna unit is usually composed of two units, namely the excitation unit and the reflection unit. The block communication antenna can basically achieve the effect of the Yagi antenna, and can UAD gain over the entire frequency band, which is slightly weaker than the Yagi antenna and slightly higher than the back of the Yagi antenna strip. Throughout the entire frequency band, the standing wave ratio of the antenna units before and after modification, rather than an Yagi antenna, can be rounded to a smaller extent, and it is important to note. When lifting a cash antenna, it is necessary to strengthen the main force of the two antenna components, otherwise it is easy to break the usually fragile mechanical resistance in strong winds.

6. Long antenna (long wire antenna)

The antenna length is also connected in a common form, mainly created by threads in one direction, and used in the network and balanced unbalanced converter to replace the restricted area for matching, in order to cover as many frequency bands as possible. The short-term average time of the frequency bands is 22.5 meters and 39 meters, combined with 1: unbalanced and soil 9 ground networks. The long-term effectiveness of an antenna is smaller than that of a half wave dipole of an antenna, mainly because the length of the radiation field of a long antenna cannot be directed towards a certain distance. For example, when used for other types of electromagnetic fields in a half wave dipole antenna, a directional array is simply treated as a composite layer. The longer the duration of the call, the clearer the wolf, as its radiation in space is a true cone, so these two planes will become more prominent. Meanwhile, the angle of the larger length and smaller maximum radiation lobe is shown. Produce a single length antenna, with the most HAM as a degree.