Everyone and everyone has long known about the purpose of television antennas - these are devices designed to receive and transmit a digital or analog signal to TV equipment. Traditionally, antennas are divided into three types: indoor, outdoor and hybrid, combining features of both types at the same time.
Initially, when television broadcasting was just beginning to develop, and televisions did not have such multifaceted functionality, the signal quality (especially at a considerable distance from the source) left much to be desired. Passive antennas, serving only as a receiver, could not provide pictures and sound of a proper quality, which left a strong imprint on the popularization of media technology and television broadcasting in general. It was then that the antennas began to be equipped with special amplifiers, which greatly increased the quality of the signal entering the TV receiver.
Today, a huge number of companies around the world are engaged in the development of antennas, however, not all are suitable for domestic data transmission standards and requirements for perceived frequency ranges. We have selected 15 of the best TV antennas in three main categories for our purchase recommendation, which have received the highest ratings from consumers.
The choice of devices was made taking into account:
- Technical characteristics
- Customer Reviews
- Antenna cost (value for money)
- The opinions of experts in the electronics market
- User voting results
Best indoor antennas for digital TV
Indoor antennas work in the decimeter or meter range, receiving a signal at a distance of up to 30 km. Such devices have some restrictions on the quality of TV waves, and need careful tuning. However, they are compact, inexpensive, and can be moved anywhere without too much trouble. The leader in the market for indoor digital television antennas is the manufacturer Remo.
5 Selenga 104A
Better signal reception outside the city. Active amplification
Country: China
Average price: 415 rubles.
Rating (2019): 4.2
The television indoor antenna from the Selenga company is made of metal and plastic, made in China, the product is not subject to mandatory certification. Packaged in a transparent bag with a colored flap - quite a familiar solution for this price category. The characteristics indicate active gain, which means that the terrain, weather and the nature of the relief do not significantly affect the operation of the TV antenna. The received signal of any power will be amplified, it becomes possible to adjust the reception settings. The device is powered by an antenna cable, therefore it is compatible with any TVs.
Commentators discuss on the forums both the pros and cons of this device. In the conditions of summer cottages and the private sector, TVs with a Selenga amplifier work mostly well. There are slight complaints about the cable length (the manufacturer has attached a 1.5-meter wire). The design is not the most compact, so it may be difficult to install and secure.
4 Delta K131A.03
The presence of an amplifier. Suitable for urban conditions
Country: China
Average price: 930 rubles.
Rating (2019): 4.5
Compact indoor antenna ideal for urban and suburban environments. Receives signals of analog and digital TV broadcasting. The UHF 40 dB amplifier allows you to confidently use the TV signal, even when the window is located at the corner of a brick house, and the tower can be located on the opposite side of the building. UHF-band, called "seventy" in the professional environment (wavelength is 70 cm), is ideal for urban environments. But in the forest and in open space, the waves damp out, they do not bend around the relief well enough, therefore, the TV antenna is not always suitable for summer cottages and villages.
Judging by the reviews on the Web, users like the small dimensions of the home device, light weight (only 700 g). The steel construction provides strength, but the assembly itself leaves a lot to be desired: the connections outside the case are soldered and not secured. The device is delivered assembled; before the first use, the antenna wire core will have to be tightened to the clamp in the receiver, which is included in the package, or terminated with a plug yourself.
3 Hyundai H-TAI320
Better adaptability to the setting of structural elements
The country:
Average price: 680 rubles.
Rating (2019): 4.7
An interesting example of a home antenna for analog and digital television, showing, in general, similar results with models such as HARPER ADVB-2120. The closed loop of the original form is combined here at once with two "horn" antennas (articulated with the body), due to which extensive tuning possibilities for normal signal reception are provided. By the way, Hyundai H-TAI320 is capable of operating both in the VHF frequency range (87.5-230 MHz) and in the UHF range (470-862 MHz), and with a sufficient degree of picture quality.
Good quality is achieved, first of all, due to the presence of a built-in amplifier, the gain of which is quite good 30 dB. There is a possibility of receiving digital signals of the DVB-T and DVB-T2 format, as well as FM and DAB. The key advantage of Hyundai H-TAI320 is the ratio of cost to quality. Having performance indicators identical to competitors, this model has a disproportionately large tuning radius of the receiving elements, which is especially important in conditions of interference concentration.
2 HARPER ADVB-2120
The optimum ratio of price and quality
Country: China
Average price: 570 rubles.
Rating (2019): 4.7
The second line of the rating of the best indoor digital TV broadcasting antennas goes to HARPER ADVB-2120. This model has a whole range of optimal characteristics, supported by a huge number of complementary reviews from domestic consumers. A wide range of captured frequencies (from 87.5 to 862 MHz) and the ability to amplify not only digital, but also analog channels (FM, VHF and UHF) are included in a pleasant "synthesis" with an original design, thanks to which the antenna can fit into any interior. It is also important that the signal amplifier is powered directly from the receiver or TV, since it does not have an external network adapter. This imposes some restrictions on the use of the antenna (since not all models of digital equipment support the possibility of direct power supply), however, it has a positive effect on its compactness.
The ergonomic characteristics of the HARPER ADVB-2120 are also at a height: the antenna can be easily placed on a plane if there is enough free space. Otherwise, the shape of the closed ring makes it possible to simply and easily hang it on any convenient hook. As a result, given the low cost, all of the above characteristics make this model one of the best in its category.
1 LUMAX DA1502A
Three-meter cable. Nice price
Country: China
Average price: 900 rubles.
Rating (2019): 4.8
A cute little device completely ready to use after purchase. It does not require additional assembly effort - you just need to place it behind the TV and point it towards the tower. With the DA1502A, you can enjoy the advantages of digital terrestrial broadcasting in accordance with European standards DVB-T / DVB-T2. Although the antenna is considered a home antenna, it is practiced outdoor placement on the outer wall of the house. Moreover, the quality of the case is so high that it is not damaged when dropped from the sixth floor (information from reviews on the Internet).
Antenna owners say that the best signal quality can be achieved at a height of at least 3.5 - 4 meters above the ground. The 28 dB UHF signal amplifier is rather weak, plugs into the USB connector, so it only works in conjunction with relatively new TVs. The set includes a 3 m cable, which gives more freedom to find the optimal location of the antenna in the house. Consumers consider this offer very beneficial, since the characteristics of the model clearly exceed the low cost. Also, among the pluses, a two-year warranty from the manufacturer is noted.
Best outdoor antennas for digital TV
Outdoor antennas for digital television have high power, due to their special design, and can receive a signal at a distance of up to 50 km. In this case, it is worth considering the presence of large obstacles in the path of transmission, which can interfere with the passage of television waves. Devices are capable of receiving a signal at a greater distance, however, in this case, you should pay attention to models with an amplifier.
5 REMO BAS-1111-P Pechora
Resistance to atmospheric influences. Asymmetrical arrangement of elements
Country Russia
Average price: 355 rubles.
Rating (2019): 4.0
This outdoor TV antenna is best suited for outdoor use. The body is covered with a special polymer, so you shouldn't be afraid of adverse weather conditions (rain, snow). The device is designed without an amplifier, in the form of a passive receiver. It qualitatively performs its direct function in the zone of reliable reception or line of sight to the transmitting center. The technical specifications indicate that the distance to the TV transmitter should not exceed 20 km. Such restrictions do not allow recommending this device to a wide range of buyers, but users who are within a radius of reliable reception are satisfied with the quality of work.
Experienced buyers do not get tired of repeating in reviews that before buying, you need to understand the initial conditions for installing a TV antenna. The proposed design with an asymmetric arrangement of elements (the so-called log-periodic antenna system) covers a wide frequency band, it ideally works for 1-2 TVs within 20 km of the line of sight of the TV tower. SAT-SH plug, F-connector, coaxial cable, bracket and signal divider are sold separately.
4 Hyundai H-TAE240
The best ratio of price and quality. detailed instructions
The country: South Korea (made in China)
Average price: 875 rubles.
Rating (2019): 4.5
Simple outdoor model with no frills, really easy to install. Designed to be placed on the wall of the house. Starts to catch the TV signal literally at the moment of connection. The coaxial cable is connected to the TV antenna using an F-type connector. Output impedance 75 ohms.
In the reviews, complaints were noticed that the device does not look very presentable from the street. But critics agree that for the money, looks don't really matter. The passive type for digital terrestrial TV has its advantages: an ordinary metal frame is durable, it is quite inexpensive, and with proper installation and operation, it is not susceptible to short circuits. Among the shortcomings of the passive system, we note the absence of an amplifier, the need for installation on a mast or pole, as well as some difficulty in positioning in relation to a television tower. Also, the reception quality is affected by various factors such as high-voltage lines, trees, bad weather. Therefore, analyze your area before purchasing a product.
3 REXANT DVB-T2 RX-411 34-0411
High degree of structural reliability
Country: China
Average price: 1 279 rubles.
Rating (2019): 4.8
An eight-element outdoor receiver for digital and analog TV signals, which is a bright representative of the average with an optimal balance of price and quality. The built-in amplifier REXANT DVB-T2 RX-411 34-0411 has a gain of 34 dB, due to which it provides excellent picture quality even with weak satellite broadcasting. As for the "ground" operational characteristics, then for urban realities they are more than reasonable, without claims to outstanding performance. It is advisable to install the model on masts with a total height of up to 7 meters from the ground. In case of underestimation of the antenna (apartment variant of placement "near the window"), there is a possibility of encountering a problem of interference, which leads to a periodic failure and "crumbling" of the picture. From the standpoint of constructive reliability, REXANT DVB-T2 RX-411 34-0411 performs very well, and, according to user reviews, it can work properly even in the most severe climatic conditions for 7 years.
2 Funke ODSC100
Best design. LTE INERT technology
Country: Holland
Average price: 2 320 rubles.
Rating (2019): 4.9
The features of this model are 24 dB gain and an extended operating range (174-240 MHz / 490-862 MHz). LTE INERT technology with filters and shielding allows the antenna to block out interference from other networks. Compact dimensions combined with a stylish minimalist design allow using the device both from the outside of the wall and indoors. But the manufacturer positions the device as external. The mount is well thought out, so the ODSC100 can be easily installed horizontally and vertically. They say that simply putting the successor behind the TV is enough to get the job done.
The built-in amplifier is powered from the tuner. If necessary, the power injector and the cord have to be purchased separately, which not all owners like. But in general, this is not considered a disadvantage, but rather a minor inconvenience. To receive a terrestrial digital and analogue TV signal, you need a modern TV with a DVB-T2 tuner or a corresponding set-top box.
1 Locus Meridian 07AF Turbo
Turbo Line with Patented Balanced Amplifier
Country Russia
Average price: 800 rubles.
Rating (2019): 4.9
Here is one of the best quality outdoor antennas from the Locus brand. Consists of 7 aluminum elements, dimensions are 501x333x60 mm, weighs 390 g - a fairly compact model by the standards of external external devices for receiving a signal. The manufacturer has received a patent for a high-frequency balanced amplifier, the task of which is to improve the signal-to-noise ratio by 3 dB compared to competitors. This is a huge plus for the reception range and picture stability.
To receive the highest quality signal, the TV must supply power to the antenna input, but not all TV models have this option. The manufacturer recommends using the LI series power injector for these purposes (not included in the basic kit). If you use a set-top box, you need to activate the antenna power through the menu. According to the official specifications, the receiver can operate with 21-60 channels in the frequency range 470-790 MHz. It is connected via an F-connector (wrap-around connector) for a coaxial cable. Users say that this is the optimal model for difficult areas, rough terrain, elevation differences, and more.
The best satellite dishes (dishes)
Satellite antennas (or simply dishes) are the most modern of all types of antennas. They boast a wide range of received signals and good quality. However, their cost is an order of magnitude higher than other types.
5 Supral 80 cm
Strong hold. Double anti-corrosion coating
Country Russia
Average price: 1 350 rubles.
Rating (2019): 4.1
The "Supral" satellite antenna with a diameter of 0.8 m is best suited for a 48 dbW signal. This model will be an excellent choice for those who do not want to overpay for extra centimeters and want to play it safe against signal deterioration in case of increased cloudiness, rain and snowfall. If it is not securely attached to the outer bracket, the standard "saucer" can move from strong winds, but the manufacturer has solved the problem. The factory control has confirmed the high quality of the power attachment of the slewing bearing to the wall bracket; the element can withstand wind gusts up to 25 m / s.
The azimuth-elevation suspension is a rigid fixed mount. This is a simple and relatively cheap design, but it allows you to tune to a single satellite. Manually adjustable horizontally and vertically only. If desired, the system can be deployed and tuned to another satellite, but a complete reconfiguration is required. Users love that a bracket is included, but the converter needs to be purchased separately. Double anti-corrosion coating extends service life.
4 WISI ORBIT Offset 80 cm
Aluminum alloy in the base. Convenient cable duct
Country: Spain
Average price: 5,700 rubles.
Rating (2019): 4.3
The aluminum reflector is very light (6 kg), so the load on the bracket is minimized. The manufacturer made a simple and very elegant move: the cable from the converter to the receiver is laid in the converter holder through a special channel. Up to four cables with a diameter of 6 mm can be pulled there comfortably. This design feature looks aesthetically pleasing and quite practical: the hidden cable lasts longer and better.
A long-focus satellite dish with an aperture angle of 72⁰ delivers a maximum quality signal to a mirror diameter of 80 cm.Let's list the main advantages of offset satellite antennas: the surface is not shaded by a converter and other elements, the efficiency is higher than that of a direct focus analogue, Offset dishes are mounted vertically and are not assembled in the bowl of precipitation. The irradiator is located below the center of gravity, so the structure can withstand wind loads better (525N). According to buyers, this model is expensive, but it fully meets the requirements for signal quality.
3 Triax TD-064
Choice of colors. European production
Country: Denmark
Average price: 1,550 rubles.
Rating (2019): 4.5
The attractive appearance of TRIAX satellite devices is the hallmark of the brand. The TD-064 model can have a classic white finish or a more avant-garde black, red-brown or anthracite gray design. In the design, every little thing is thought out, starting with the ease of installation. So, the holder with a scale allows you to set the device very accurately. The manufacturer has taken care of compliance with the ETSI (European Telecommunications Standards Institute) regulations. The wind resistance test has been successfully passed according to the ETS 300158 standard.
The gain is 35.8 dB at 11.7 GHz with a frequency range of 10.7 - 12.75 GHz. The galvanized steel mirror has dimensions of 600x650 mm. Users note in the reviews the stable operation and durability of the device, as well as the amazing resistance to wind load (up to 42 m / s). The Danish-made satellite dish supports operators such as NTV +, MTS, Tricolor TV.
2 Lans-65 MS6506
Good signal even in bad weather
Country: China
Average price: 2,500 rubles.
Rating (2019): 4.6
The second place in the ranking of the best satellite dishes is the Lans-65 MS6506 model. This cymbal has a rather unusual design with a parabola geometry and special perforation. This combination allows the antenna to clean itself independently, which has a positive effect on the quality of the received signal. In addition, the perforation significantly reduces the wind load of the entire structure and makes it lighter.
Among the advantages in the reviews, buyers point to a pleasant appearance, excellent reception quality and ease of setup. A special powder coating protects the cymbal from premature failure, and the reinforced mount allows for smooth elevation adjustment. The disadvantages of using include periodic signal jumps.
1 AUM CTB-0.6 DF - 1.1
The best signal quality for NTV + and Tricolor TV
Country: Belarus
Average price: 1,150 rubles.
Rating (2019): 4.7
The first place in the rating of the best satellite dish antennas is occupied by the AUM CTB-0.6 DF - 1.1 model. The product from the Belarusian manufacturer is recognized as one of the most suitable for working with NTV + and Tricolor TV. The device has a good gain, which allows it to function in cities, even with dense buildings. A distinctive feature of this antenna is not a round, but an ovoid shape, which is done to improve reception.
In the reviews, users talk about high quality workmanship, low cost and ease of customization. For quick installation, the kit includes all the necessary fasteners. If necessary, the standard boom can be easily replaced with a longer one for better reception. The disadvantages include only poor-quality packaging of additional components.
How to choose a good antenna
The choice of television antennas, like many other devices, is accompanied by some nuances that should be inquired about in advance. We strongly recommend that you pay attention to the following parameters:
Antenna type. Depending on the place of application, antennas are divided into indoor, outdoor and hybrid, which can be placed in both conditions. If the received signal is sufficiently stable and confident, a simple indoor antenna can be dispensed with. Otherwise, you should give preference to hybrid or full-fledged street options.
Antenna range. In this case, antennas are divided into two types: broadband and narrowband. The first option is advisable to apply when the frequency of TV broadcasting is not known in advance. This option is suitable for thrifty owners, in case new channels appear on the air. Narrowband antennas are oriented to a certain frequency and it is impossible to rebuild them to other bands without losing the current one.
Strengthening the signal. This function is inherent exclusively in active antennas, in the design of which the presence of an additional module is provided. This embodiment is suitable when the received signal requires amplification to generate a clear and high-quality image on the TV screen.
Antenna directivity. A simple and unpretentious way to improve the quality of the signal by shifting the radiation pattern allows antennas to carry out accentuated reception only at a strictly defined azimuth. This effect allows you to avoid interference caused by the reflection of various signals from the walls of residential buildings and other "initiating" objects.
Antenna internal impedance. It is very important that this parameter matches the resistance of the cable connected to the device. The standard impedance of the equipment for receiving a TV signal is 75 ohms, and for a radio signal it is 50 ohms.
Design. The aesthetic side of the issue when buying a television antenna should also not be left out. Often, a pleasant appearance indirectly affects the improvement of the quality of the applied signal, since the correct geometry and rational arrangement of additional elements affects the physical parameters.
A. Kalashnik
Radio hobby 1/2001
VHF antennas
In recent years, the interest of radio amateurs in the 2-meter range is constantly growing due to the increase in the number of FM repeaters and, accordingly, the improvement of conditions for the development of mobile communications, a network of various BBS and portals, incl. with Internet access, as well as satellite repeaters. The increase in activity is also facilitated by the permission from March 1, 1998 to work on VHF for novice radio amateurs.
When working on the 2-meter range, antennas are used both with vertical polarization (mainly for mobile communications and when working through repeaters), and with horizontal. In this case, it is desirable to have an antenna with a circular radiation pattern in both the horizontal and vertical planes. The latter is very important when working through satellite (AES) repeaters. For these purposes, as a rule, several antennas are used, which reduces efficiency in operation, provided that long-range unstable transmission on the 2-meter range is required.
The author managed to solve this problem by implementing an antenna with an almost spherical directional pattern. In this case, the antenna can emit and, accordingly, receive electromagnetic waves with both vertical and horizontal polarization.
The design is based on the popular J-antenna (Fig. 1). It is a vertical dipole fed from the lower end using a short-circuited quarter-wave line. As you know, this antenna works only with vertical polarization and has a circular pattern in the horizontal plane with a deep minimum in the vertical direction.
The author proposed to change the shape of the vertical radiator of this antenna, bending the dipole in half at 90 °. In this case, the horizontal part of the dipole in the first version consisted of two opposite elements of length L / l each (Fig. 2) and was first described in the collection "Infoix" No. 4/1990, p. 42,43.
In the last modification, the author proposed to make the horizontal part of the radiator from 4 mutually perpendicular segments of length l / 4, having electrical contact with the vertical part of the radiator (Fig. 3). The antenna design is easy to manufacture and easily repeatable even for novice radio amateurs. The vertical parts of the antenna are made of a pipe with a diameter of 32 mm. Material - bronze, brass, copper, as well as aluminum alloys, provided that reliable electrical contact of all parts of the antenna and the matching device is ensured (soldering or welding). The horizontal cruciform part is made of a rod or tube with a diameter of 6 mm (the material is similar to the used tube with a diameter of 32 mm).
This design retains the advantage of a J-antenna in that the lower end of the short-circuited quarter-wave line can be grounded, for example electrically connected to a grounded mast, in which case the entire antenna can serve as a good lightning conductor. The setting consists in selecting the place for connecting the power cable to the matching line (Fig. 4) at a minimum SWR. The author used the RC-75. however, a 50 ohm feeder can also be used. With the dimensions indicated in Fig. 3, 4 and a 75-ohm feeder, VSWR = 1.0 near 145.5 MHz.
The antenna is mounted on a metal earthed mast, at a height of 7 m above the ground, but a mast of any material and design can be used. Foreign conductive objects should be removed from horizontal elements by more than 2 meters. With a corresponding change in the geometric dimensions, such an antenna can be built for other VHF bands.
This antenna has been with the author since 1983. It showed good results in all types of transmission, as well as in communications through amateur satellites in their visibility zone and without a signal failure "overhead". During the "Field Day 2000" an experiment was carried out on the basis of UT0H, during which the signals of my beacon, on which the described antenna was used, were received by antennas with both vertical and horizontal polarization with approximately the same loudness.
From the editor. Figures 1 and 4 show two options for connecting the cable to the matching line. In the first case (Fig. 1), the central core is soldered to the line conductor connected to the emitter, and in the author's version (Fig. 4) - vice versa. Both options are equivalent, although in the publication "the cable connection method shown in Fig.1 is more common.
Literature
- Benkovsky 3., Lipinsky E. Amateur antennas of short and ultra-short waves: Per. from Polish / Ed. O. P. Frolova. - M .: Radio and communication, 1983.. 480 p., Ill. - (Mass radio library; Issue 1052)
The classic version. Both antenna sections are installed vertically. Used mainly at HF.
Such a vertical antenna is well known to VHF lovers as a J-antenna. The figure shows the general layout of the antenna - the classic version. It consists of two sections: emitting L / 2 and matching L / 4. The high impedance of a half-wave emitter can be matched (reduced) to a low impedance by using a quarter-wave terminated at the end of the line. This method has been known for a long time and is widely used in practice.
On a quarter-wave line, you can find two XX points with an impedance of 500m (or 750m) to connect the corresponding coaxial cable (feeder). When connecting the cable, it is advisable to provide a balancing choke or transformer. The quarter-wave line itself is easiest to make from 450-ohm ribbon cable.
DK7ZB has manufactured and tested several similar antennas for the amateur bands 2, 6, 12 and 30 meters. I brought the data for the remaining ranges into a table, which is very convenient to use when experimenting. Below he gives mathematical calculations for independent calculations, based on the specific calculation conditions:
Emitter: L / 2 = 0.471 X (m) - copper insulated wire 2mm;
Quarter wave line: L / 4 = 0.223X (M) - 450-ohm ribbon cable (Wireman);
Points XX are located approximately 5 ... 10% of the closed end of the quarter-wave line.
When installing the antenna, in addition to the main vertical position, the following options may be considered:
Estimated dimensions:
Diap. L / 2 L / 4 XX MHz SWR Bandwidth (kHz) (m) (m) (m) (cm) (SWR
Calculated values marked with (*) require rechecking.
The quarter-wavelength (X / 4) line lengths are given for WireMan 450-ohm RF ribbon cable.
The values given in the table are valid for free installation of the antenna in space. If the radiating wire is fixed on any supporting insulated elements, then its length should be reduced by approximately 2 ... 3%, because the operating frequency in this case decreases
To conduct local communications on VHF (including through repeaters), an antenna is needed with a circular radiation pattern and noticeable gain. In amateur radio practice, this problem is usually solved by using elongated vertical antennas, consisting of several radiators, which are fed through phasing two-wire lines. Many foreign companies produce very similar antenna models, and almost identical models are sometimes produced under different names. A typical antenna of this class (for example, the ARX-2B model from CUSHCRAFT) has a gain of 7 dB and a VSWR at the resonant frequency no more than 1.2 (typical value). The bandwidth is about 3 MHz. In the horizontal plane, the antenna has a circular radiation pattern, in the vertical plane, the maximum radiation angle is 7 degrees. Usually, antennas have a certain margin for adjustments, therefore, during installation, their operating frequency can be varied over a wide range (for example, for the above model, in the band from 135 to 160 MHz). Similar antennas can be made in an amateur environment.
The design of this type of antenna is shown in Fig. 1. It is made of thin-walled aluminum tubes and installed through an insulator on a grounded metal mast (total antenna height is 4.3 m). Antenna dimensions are for the amateur band of 2 meters, with a center frequency of 145 MHz.
Element 1 is a tube 890 in length and 9 mm in diameter. A plug is installed in the upper part of element 1 to prevent moisture from entering the antenna. Element 3 is a tube 700 in length and 13 mm in diameter. Element 6 is a tube 530 in length and 13 mm in diameter. Element 7 is a tube 380 long and 16 mm in diameter. Element 8 is a tube 1000 in length and 19 mm in diameter.
At the upper ends of the tubes 3, 7, 8, vertical cuts are made with a length of 30 mm, providing a tighter fit of the internal fixed elements. The fixation of the tubular elements is carried out with the help of expanding clamps 2, a sketch of which is shown in Fig. 2. The design uses three clamps with internal diameters D = 13, 16 and 19 mm.
Elements 3 and 6 are electrically connected to each other through a phasing element 5. For this, an insulator is installed between elements 3 and 6, Fig. 3. The phasing element is a U-shaped bracket made of 6 mm diameter aluminum wire. At the ends of tubes 3 and 6, inserted into the insulator at a distance of 10 mm from the edge, holes with a diameter of 6 mm are drilled. With the help of M5 screws through the threaded holes in the insulator, elements 3, 5 and 6 are fastened together. The length of the phasing element 5 is set according to the dimensions shown in Fig. one.
The antenna is installed through an insulator 11 (Fig. 4) on a metal mast 17 with a diameter of 32 mm. At the upper end of the mast fixed (welding or any other mechanical connection) a metal glass 16 with an internal diameter of 32 mm. An insulator 11 is placed in this glass. The depth of the glass 16 is chosen so that the insulator 11 protrudes from it by 30 mm.
Metal corners 13 are fastened to elements 8 and 16, as can be seen in Fig. 1, with screws 13. At the ends of the corners remote from the antenna, one hole with a diameter of 127 mm is drilled from a copper wire with a diameter of 5 mm.
On the corner attached to part 16, closer to the antenna, a 50-ohm socket is installed so that its threaded or bayonet part faces downward towards the antenna base. A piece of copper wire 12 with a diameter of 5 and a length of 130 mm is soldered to the central terminal of the connector (Fig. 5).
At one end, the wire is flattened and a hole is drilled in it equal to the diameter of the center terminal of the connector. The wire is bent so that it, without touching the antenna, lies with its opposite end on element 9. With the help of a metal bracket (detail 10, Fig. 6) and an M5 screw on the bracket, the end of wire 12 is fixed on element 9. В at the same time, this contact is movable and is used when tuning the antenna. Moving within some limits the bracket 10 around the circumference of the ring 9, choose such a position in which the antenna SWR is minimal.
Before its installation, a metal ring 18 is put on the antenna mast, made according to Fig. 7. Three aluminum counterweights 19, 521 in length and 6 mm in diameter, are screwed into this ring. At one end of the counterweights, a 20 mm long M6 thread is cut. Before installing the counterweights in place, locknuts are screwed onto the threads.
To conduct local communications on VHF (including through repeaters), an antenna is needed with a circular radiation pattern and noticeable gain. In amateur radio practice, this problem is usually solved by using elongated vertical antennas, consisting of several radiators, which are fed through phasing two-wire lines. Many foreign companies produce very similar antenna models, and almost identical models are sometimes produced under different names. A typical antenna of this class (for example, the ARX-2B model from CUSHCRAFT) has a gain of 7 dB and a VSWR at the resonant frequency no more than 1.2 (typical value). The bandwidth is about 3 MHz. In the horizontal plane, the antenna has a circular radiation pattern, in the vertical plane, the maximum radiation angle is 7 degrees. Usually, antennas have a certain margin for adjustments, therefore, during installation, their operating frequency can be varied over a wide range (for example, for the above model, in the band from 135 to 160 MHz). Similar antennas can be made in an amateur environment.
The design of this type of antenna is shown in Fig. 1. It is made of thin-walled aluminum tubes and installed through an insulator on a grounded metal mast (total antenna height is 4.3 m). Antenna dimensions are for the amateur band of 2 meters, with a center frequency of 145 MHz.
Element 1 is a tube 890 in length and 9 mm in diameter. A plug is installed in the upper part of element 1 to prevent moisture from entering the antenna. Element 3 is a tube 700 in length and 13 mm in diameter. Element 6 is a tube 530 in length and 13 mm in diameter. Element 7 is a tube 380 long and 16 mm in diameter. Element 8 is a tube 1000 in length and 19 mm in diameter.
At the upper ends of the tubes 3, 7, 8, vertical cuts are made with a length of 30 mm, providing a tighter fit of the internal fixed elements. The fixation of the tubular elements is carried out with the help of expanding clamps 2, a sketch of which is shown in Fig. 2. The design uses three clamps with internal diameters D = 13, 16 and 19 mm.
Elements 3 and 6 are electrically connected to each other through a phasing element 5. For this, an insulator is installed between elements 3 and 6, Fig. 3. The phasing element is a U-shaped bracket made of 6 mm diameter aluminum wire. At the ends of tubes 3 and 6, inserted into the insulator at a distance of 10 mm from the edge, holes with a diameter of 6 mm are drilled. With the help of M5 screws through the threaded holes in the insulator, elements 3, 5 and 6 are fastened together. The length of the phasing element 5 is set according to the dimensions shown in Fig. one.
The antenna is installed through an insulator 11 (Fig. 4) on a metal mast 17 with a diameter of 32 mm. At the upper end of the mast fixed (welding or any other mechanical connection) a metal glass 16 with an internal diameter of 32 mm. An insulator 11 is placed in this glass. The depth of the glass 16 is chosen so that the insulator 11 protrudes from it by 30 mm.
Metal corners 13 are fastened to elements 8 and 16, as can be seen in Fig. 1, with screws 13. At the ends of the corners remote from the antenna, one hole with a diameter of 127 mm is drilled from a copper wire with a diameter of 5 mm.
On the corner attached to part 16, closer to the antenna, a 50-ohm socket is installed so that its threaded or bayonet part faces downward towards the antenna base. A piece of copper wire 12 with a diameter of 5 and a length of 130 mm is soldered to the central terminal of the connector (Fig. 5). At one end, the wire is flattened and a hole is drilled in it equal to the diameter of the center terminal of the connector. The wire is bent so that it, without touching the antenna, lies with its opposite end on element 9. With the help of a metal bracket (detail 10, Fig. 6) and an M5 screw on the bracket, the end of wire 12 is fixed on element 9. В at the same time, this contact is movable and is used when tuning the antenna. Moving within some limits the bracket 10 around the circumference of the ring 9, choose such a position in which the antenna SWR is minimal.
Before its installation, a metal ring 18 is put on the antenna mast, made according to Fig. 7. Three aluminum counterweights 19, 521 in length and 6 mm in diameter, are screwed into this ring. At one end of the counterweights, a 20 mm long M6 thread is cut. Before installing the counterweights in place, locknuts are screwed onto the threads.
An angle 13 is attached to part 18 with a screw by analogy with part 16. Only the connector is installed here through the passage. A cable with connectors at the ends and a total length of 1272 mm is produced separately.
A ring 18 is installed on the length of the tensioned attached cable and, screwing in the counterweights to the stop, rigidly fix it on the antenna mast. After that, the locknuts are tightened.
The lengths of the tubes given in this article correspond to the version of the antenna that allows you to tune its operating frequency over a wide range. For an antenna for a range of 2 meters, the radiators can be non-composite, which will significantly simplify the antenna design.
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