Antenna diamond f23 description. Antennas and their settings. Delivery through a transport company "to the warehouse"

In order to assemble this antenna you need 4.5m of aluminum wire with a diameter of 2.5mm, copper wire with a diameter of 1.2mm, 1.5mm and 4m of plastic pipe with a diameter of 25mm.

Dimensions are shown in the picture. The coils are made and fixed on flat textolite frames; the foil is left at the edges and the coils are welded to them. The matching coil is soldered to the connector body. The textolite plate is soldered on one side to the central terminal of the connector, and the other terminal of the coil is soldered to the opposite side. A capacitor with a capacity of 5.6 pf is located inside the coil.

The photo shows the coils that I use. The antenna elements are attached using electrical terminal blocks, which can be purchased at the store. Terminal blocks made of brass need to be soldered to the pads to which the coils are already soldered.

All elements, starting from the top, are assembled and fastened with screws, after which the entire antenna is carefully inserted into the plastic pipe. To get rid of the rattle effect, you can use paralon or pieces of fiberglass equal to the inner diameter of the plastic pipe.

Fastening to the mast is carried out using a glass 50mm high with a diameter of 25mm (for my case). At a distance of 20mm from the top edge of the glass, three holes for counterweights with a diameter of 5mm are drilled. The length of the counterweights is 51cm. The two washers in the figure are for the version of the collapsible camping antenna (2 x 2m).

I express my deep gratitude to Oleg RW4PJD for the opportunity to take measurements from his antenna. Please send questions to:

Victor Oleinik (UA4PJT), This email address is being protected from spambots. You must have JavaScript enabled to view it.

Modification of f-23:

A small tweak to the setup!
Today I set up another such antenna! Super! Here's the description.
1. The circuits are tuned to Resonance at medium frequencies of 144.8 MHz-146. MHz.
2. Input circuit L1 is set to 145 MHz. This is what the MFJ-269 showed. The only advice is to solder a small 3pf constant capacitor in parallel - a trimmer from 2-25 pf. It will help you in further setting up the input circuit!
3. First, solder the 1st wire with a reserve and adjust its length to resonance at 146 MHz (without Resonance Coils)!!! If the resonance is gone, then we bite off or add length to the wire. The second one is similar - (top piece of wire)!
4.Now let’s tune the Middle wire to resonance at 145 MHz.
5. To each of the pieces L2-L3 we solder boards with resonant coils.
6. Connect the cable and check what has escaped and where. If we go down in frequency (then we will wind several turns on an 8mm mandrel at the bottom) and thus adjust the frequency and resonance we need!
Using MFJ-269, this design was driven into resonance at 145.5 MHz at ksw=1.0 RX=0 R=52Ohm.
Good luck repeating: UA9JAI SURGUT SERGE-73!

The X-200 is a dual-band (144/430) colinear antenna with an omnidirectional pattern and high gain.

The first such antenna was made in the late 90s and even still works. X-200 in English. Below is the antenna diagram:

The antenna is made entirely (including all coils) of solid copper wire with a diameter of 2 mm without intermediate soldering. All reels are frameless. Capacitor C1 is made from a piece of SAT-703 coaxial cable 2 cm long - it is for the system to operate on the 70 cm range. Capacitor C2 is an air capacitor, a tuning capacitor - we use it to tune the antenna.

Well, everything is clear with the electrical part - let's move on to the technical implementation.

The power load was carried by the wooden handle of a shovel (only slightly more powerful than what is sold in stores).

A fiberglass fishing rod was attached to it with electrical tape (now the issue can be solved more beautifully, of course) lightly (so as not to pinch), inside which everything that was wound with back-breaking labor was placed, i.e. the antenna itself, lined with anti-bounce foam pads with all coils (except L4 and capacitors).

Two through holes were drilled in the handle 5 cm below the L4 coil, perpendicularly, but with a height difference of 5 mm, for future counterweights. Counterweights were inserted and soldered. Their fastening can be seen schematically below:

Now setup.

First of all, you need to configure the parallel circuit C1/L4 to the average frequency of the 70cm range - it is this that allows you to power the entire structure at these frequencies. The location of the tap in L4 determines the transformation ratio. Well, if there is nothing to check, then leave it as it is. I have never checked this either, because... at that time there was nothing.

I made adjustments only according to the readings of the SWR meter right in the room, placing the antenna horizontally. High ceilings made this possible. The adjustment is made by rotating rotor C2. It should be noted that if it is not possible to “immediately” obtain the necessary indicators by agreement simultaneously in both ranges, you need to select a tap from the L4 coil.

As a result, I got very good results according to the agreement:

145MHz - SWR=1.03

435MHz - SWR=1.02

After adjustment, an empty Sprite bottle was placed on top of the matching unit, which protected all open parts from moisture. After 10 years, this bottle lost its green color.

Diamond F23 is an omnidirectional antenna for fixed stations of VHF radio communication systems. It is used by radio amateurs as a base station antenna, as well as by departmental organizations when building land mobile radio communication systems.

Setting up the Diamond F23 basic antenna is carried out by trimming the antenna sheet according to the attached instructions. This is not always easy to do, since the pin and each of the elements are protected by a fiberglass casing, which provides high resistance to wind loads. As an alternative to independently modifying the design, we suggest contacting antenna equipment setup specialists who will cope with this task competently and in a short time.

Measuring the characteristics of the Diamond Diamond F23 base antenna is carried out using special instruments - SWR meters, which allow you to analyze the nature of radio wave propagation in a coaxial cable or other waveguide.

Characteristics:

• Dimensions, m: 4.6
• Operating frequency range, MHz: 144
• Body material: fiberglass
• Antenna type: vertical omnidirectional
• Gain, dBi: 7.8
• Maximum input power, W: 200
• Impedance, Ohm: 50
• Connector: SO-259
• Weight, kg: 1.7
• Mounting method: on a pipe with a diameter of 30 to 62 mm

Characteristics

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Diamond F-23 antenna in one hour

In order to assemble this antenna you need 4.5m of aluminum wire with a diameter of 2.5mm, copper wire with a diameter of 1.2mm, 1.5mm and 4m of plastic pipe with a diameter of 25mm.

Dimensions are shown in the picture. The coils are made and fixed on flat textolite frames; the foil is left at the edges and the coils are welded to them. The matching coil is soldered to the connector body. The textolite plate is soldered on one side to the central terminal of the connector, and the other coil terminal is soldered to the opposite side. A capacitor with a capacity of 5.6 pf is located inside the coil.

The photo shows the coils that I use. The antenna elements are attached using electrical terminal blocks, which can be purchased at the store. Terminal blocks made of brass need to be soldered to the pads to which the coils are already soldered.

All elements, starting from the top, are assembled and fastened with screws, after which the entire antenna is carefully inserted into the plastic pipe. To get rid of the rattle effect, you can use paralon or pieces of fiberglass equal to the inner diameter of the plastic pipe.

Fastening to the mast is carried out using a glass 50mm high with a diameter of 25mm (for my case). At a distance of 20mm from the top edge of the glass, three holes for counterweights with a diameter of 5mm are drilled.

The length of the counterweights is 51cm. The two washers in the figure are for the version of the dismountable hiking antenna (2 x 2m). I express my deep gratitude to Oleg RW4PJD for the opportunity to take measurements from his antenna. Please send questions to:

[email protected]

Diamond F-23 - basic antenna range 144-174 MHz, 200 W, gain 7.8 dBi

Attention! We supply the original Diamond F23 antenna made in Japan supplied by Diamond!

(not Chinese fakes - which are sold on various sites)Vertical antenna for base stationsDiamond F23

designed for use in the 2-meter frequency range (144-174 MHz). The use of fiberglass coating on the pin provides complete protection from bad weather conditions. The antenna comes with a durable aluminum mount for quick and secure installation on a mast. For convenient transportation, the fiberglass case is divided into three sections, and metal couplings ensure mechanical strength of the connections. Vertical antenna for base stations Professional vertical collinear VHF antenna

can be used to organize professional communication networks in the 144-180 MHz range, as well as as a base antenna for an amateur radio station or a repeater in the 144 MHz range. It is made of high-strength materials and can withstand wind gusts of up to 40 m/sec. Vertical antenna for base stations Antenna

can be used to organize professional communication networks in the 144-180 MHz range, as well as as a base antenna for an amateur radio station or a repeater in the 144 MHz range. It is made of high-strength materials and can withstand wind gusts of up to 40 m/sec. Vertical antenna for base stations It is supplied unassembled, the package length is 157 cm. When assembling the sections, tightness is ensured and it is impossible for precipitation to get inside the antenna. Tuning the antenna to different frequencies in the 144-180 MHz range will require trimming the collinear internal antenna elements according to the included trim chart. When using the antenna on the amateur band 144-146 MHz, no cutting of elements is required; the antenna will be ready for use immediately after assembly.

consists of three collinear elements of 5/8 wavelength with capacitive loads, providing high gain (7.8 dBi) with a wide bandwidth (SWR in the range 144-146 MHz no more than 1.45). The maximum power supplied to this antenna in FM mode can reach 200 Watts, the height of the antenna is 4.53 m. The antenna is designed to be powered by a coaxial cable with a characteristic impedance of 50 Ohms, a SO-239 type connector. Vertical antenna for base stations Basic vertical antenna

• Gain 7.8 dB
• Number of radiating elements --- 3*5/8
• Allowable power 200 W
• Weight 1.7 kg
• Assembled height 4.53 m
• Mounting on a mast --- diameter 30-62 mm
• SWR value<1.5:1
• Bandwidth --- 3 MHz
• Allowable wind speed 50m/sec
• Range trim map
• Russian instructions for assembly and configuration!

Many people do not understand the importance of good coordination of the Radio-Transmission Line-Antenna path. Or rather, they understand the importance, but are completely unable to really assess the state of affairs. Most often, they are content with readings of the built-in SWR meter close to unity. The most unpleasant thing about this is that if the situation is bad, the owner of the radio increases the power until they begin to answer. And how much power will be directed at the neighbor’s TV and used to heat up the atmosphere is the second question... Let’s try to figure it out.

The picture schematically shows a circuit of three devices and two transitions between them.

The secret is that the SWR meter shows what it “sees” on the transceiver connector. The remaining devices and impedances are “hiding behind” those in front, like one nesting doll inside another. And at every transition and device there are losses due to attenuation in the cable or transmission line and poor SWR. First, let's define the units of measurement. For specialists, for example in the field of agriculture, the term diBi is closer to the medical term than to the concept of “how many times”. Therefore, for starters, a table of losses in dB and a breakdown in percentages, which everyone understands well. And now a table of physical losses in lines and connections, depending on the range, calculated by a special program for modeling transmission lines, as well as losses in case of poor matching..

Looking at this picture, it’s easy to agree that in an unfavorable situation, nothing at all may get into the antenna :-).

And now closer to radio engineering. If the antenna has a real impedance equal to the resistance of the transmission line, be it a coaxial cable, a quarter-wave transformer or a tuned line, then the SWR meter at the transceiver connector will measure the real SWR of the antenna-feeder device (AFD). If not, the SWR meter will show a match with the cable rather than with the entire system. Due to the fact that it is very inconvenient to measure SWR directly on an antenna already raised above the ground, tuned lines and quarter-wave or half-wave sections of cable are often used to communicate with the antenna, which are also transformers that accurately “transmit” the SWR value of the antenna to the radio input (impedance). That is why, if the antenna resistance is unknown, or it is just being configured, it makes sense to use a coaxial cable of a certain length. The tables above will help you choose the lesser of two evils - either feeder losses or SWR losses :-). In any case, it is better to know what I described above than to remain in the dark... When choosing, installing or configuring a particular antenna, you need to know several of their basic properties, which can be described in the following concepts.

Resonance frequency

An antenna emits or receives electromagnetic waves most efficiently only when the frequency of the exciting wave matches the resonant frequency of the antenna. It follows from this that its active element, vibrator or frame has such a physical size that resonance is observed at the desired frequency.

By changing the linear dimensions of the active element - the emitter, the antenna is tuned to resonance. As a rule (based on the best efficiency/labor ratio and matching with the transmission line), the antenna length is equal to half or a quarter of the wavelength at the center operating frequency. However, due to capacitive and tip effects, the electrical length of the antenna is greater than its physical length.

The resonant frequency of the antenna is affected by: the proximity of the antenna above the ground or some conductive object. If this is a multi-element antenna, then the resonant frequency of the active element may also change in one direction or another depending on the distance of the active element in relation to the reflector or director. Antenna reference books provide graphs or formulas for finding the shortening coefficient of a vibrator in free space depending on the ratio of the wavelength to the diameter of the vibrator.

In reality, it is quite difficult to determine the shortening coefficient more precisely, because The height of the antenna, surrounding objects, soil conductivity, etc. have a significant impact. In this regard, during the manufacture of the antenna, additional adjustment elements are used, which allow the linear dimensions of the elements to be changed within small limits. In a word, it is better to “bring” the antenna to working condition at its permanent location. Typically, if the antenna is a wire dipole or Inverted V type, shorten (or lengthen) the wire connected to the central core of the feeder. So with smaller changes you can achieve a greater effect. In this way, the antenna is tuned to the operating frequency. In addition, by changing the inclination of the beams in Inverted V, the SWR is adjusted to a minimum. But this may not be enough.

Impedance or input resistance (or radiation resistance)

The smart word Impedance means the complex (total) resistance of the antenna and it varies along its length. The point of maximum current and minimum voltage corresponds to the lowest impedance and is called the excitation point. The impedance at this point is called the input impedance. The reactive component of the input impedance at the resonant frequency is theoretically zero. At frequencies above resonant, the impedance is inductive, and at frequencies below resonant, it is capacitive. In practice, the reactive component in most cases varies from 0 to +/-100 Ohms.

The antenna impedance may depend on other factors, for example, the proximity of the location to the Earth's surface or any conductive surfaces. In the ideal case, a symmetrical half-wave vibrator has a radiation resistance of 73 Ohms, and a quarter-wave asymmetrical vibrator (read pin) - 35 Ohms. In reality, the influence of the Earth or conductive surfaces can change these resistances from 50 to 100 ohms for a half-wave antenna and from 20 to 50 ohms for a quarter-wave antenna.

It is known that the Inverted V antenna, due to the influence of the earth and other objects, never turns out to be strictly symmetrical. And most often the radiation resistance of 50 Ohms is shifted from the middle. (One arm should be shortened and the other increased by the same amount.) So, for example, three counterweights slightly shorter than a quarter wave, located at an angle of 120 degrees in the horizontal and vertical planes, turn the GP resistance into a very convenient 50 Ohms for us. In general, the antenna resistance is more often “adjusted” to the transmission line resistance than vice versa, although such options are also known. This parameter is very important when designing the antenna power unit.

Non-specialists and not very experienced radio amateurs, I, for example, don’t even realize that not all active elements in multi-band antennas can be physically connected! For example, a very common design is when only two, or even one, element is connected directly to the feeder, and the rest are excited by re-radiation. There is even a slang word for this – “cross-pollination”. Of course, this is no better than direct excitation of vibrators, but it is very economical and greatly simplifies the design and weight. An example is numerous designs of tri-band antennas such as Uda-Yagi and Russian Yagi, including designs of the XL222, XL335 and XL347 line.

Active nutrition of all elements is a classic, so to speak. Everything according to science, maximum bandwidth without blockages, much better than the radiation pattern and the Front/Back ratio. But everything good is always more expensive. And heavier 🙂 Therefore, behind this is a more powerful mast, the same turn, area for guy wires, etc. and so on. For us, consumers, cost is not the last argument.

We should not forget about such a technique as symmetry. It is necessary to eliminate the “skew” when feeding a symmetrical antenna with an asymmetrical power line (in our case, a coaxial cable) and makes significant changes to the reactive component of the resistance, bringing it closer to a purely active one.
In practice, this is either a special transformer called a balun (balance-unbalance) or simply a number of ferrite rings placed on the cable near the antenna connection point.

Please note that when we say “balun-transformer”, we mean that in this case the impedance is actually transformed, and if it is just a balun, then it is more likely a choke included in the cable braid circuit.

Usually, even for a range of 80 meters, a dozen rings are enough (cable size, permeability something from 1000NN and less). On higher ranges it is even less. If the cable is thin and there are one or more rings of large diameter, you can do the opposite: wind several turns of cable around the ring(s).
Important: of all the turns that fit, half must be wound in the other direction.

On my 80-meter dipole I have 10 turns of cable on a 1000NN ring, and on my tri-band hexabim (spider) there are 20 rings put on the cable. Their total resistance (as inductance) at the operating frequency must be more than 1 kiloOhm. This will prevent the flow of current through the cable braid, thereby achieving symmetrical excitation at the connection point.

The most practical solution, which is used everywhere due to its simplicity and efficiency, is 6-10 turns of the power cable into a coil with a diameter of 20 centimeters (the turns should be secured either to the frame or with plastic guides so that the result is inductance and not a coil of cable :-). You can clearly see this in the photo. This trick will work great on your regular dipole too. Try it and you will immediately notice the difference in TVI levels.

Gain

If an antenna radiates the same power in absolutely all directions, it is called isotropic, i.e. directional pattern – sphere, ball. In reality, such an antenna does not exist, so it can also be called virtual. She has only one element - she has no enhancement.

The concept of “gain” can only be applied to multi-element antennas; it is formed due to the re-emission of in-phase electromagnetic waves and the addition of signals on the active element. Are we all familiar with the situation with poor mobile phone connections in rural areas? And how do we solve it? We find a long conductive object and bring the “mobile” to it as close as possible. The quality of communication increases. Of course, due to the re-emission of base station signals by the conductive object we found. Those who are older may remember a similar situation with transistor radios in the 60s while listening to the Beatles. Same situation. This was especially noticeable on magnetic antennas: due to the large number of turns of the magnetic antenna, the summed re-radiated voltage was greater. A special case, sometimes the word “gain” is used in relation to a single pin to determine how much the vertical component of the radiation is less than the radiation in the horizontal plane. A priori, this is not a gain - it is rather a transformation coefficient :) Do not confuse with phased or collinear verticals: they have two or more elements, and they have a real gain. The gain can be obtained by concentrating the radiation energy in one direction. The amplification is formed by adding and subtracting radio waves excited in the vibrator and re-emitted by the director. In the animated drawing, the resulting wave is shown in green.

Directional coefficient (DA) is a measure of the increase in power flow due to compression of the radiation pattern in one direction. An antenna can have a high efficiency, but a low gain, if the ohmic losses in it are large and “eat up” the useful voltage obtained due to re-radiation. Gain is calculated by comparing the voltage across the antenna being measured with the voltage across a reference half-wave dipole operating at the same frequency as the antenna being measured and at the same distance from the transmitter. Typically, gain is expressed in decibels relative to a reference dipole - dB. More precisely it will be called dBd. But if we compare it with a virtual, isotropic antenna, then the value will be expressed in dBi and the number itself will be slightly larger, because the dipole still has some directional properties - maximums in the direction perpendicular to the canvas, if you remember, but an isotropic antenna does not. The denominator has a smaller number, so the ratio is larger. But you won’t be fooled by them, we are practitioners, we always look at dBd.

Directional pattern

They try to design antennas in such a way that they have a maximum gain (receive and transmit) in a pre-selected direction. This property is called directivity. The animation shows a dynamic drawing of the addition and subtraction of radio waves excited in the vibrator and re-emitted by the reflector and director. The resulting radio wave is indicated in green.

The nature of the antenna radiation in space is described by the radiation pattern. In addition to radiation in the main (main) direction, there are side radiations - back and side lobes.

The radiation pattern of a transmitting antenna can be constructed by rotating it and measuring the field strength at a fixed distance without changing the transmitting frequency. These measurements, converted into graphical form, give an idea in which direction the antenna has maximum gain, i.e. The polar diagram shows the direction in which the energy emitted by the antenna is concentrated in the horizontal and vertical planes. In amateur radio practice, this is the most difficult type of measurement. When carrying out measurements in the near zone, it is necessary to take into account a number of factors affecting the reliability of measurements. Any antenna, in addition to the main lobe, also has a number of side lobes; in the short wave range, we cannot raise the antenna to a greater height. When measuring the radiation pattern in the HF range, the side lobe reflected from the ground or from a nearby building can hit the measuring probe, both in phase and in antiphase, which will lead to an error in the measurements.

Simple wire antennas also have a radiation pattern. For example, a dipole has a figure eight with deep dips in the diagram, which is not good. The same goes for the popular Inverted V antenna.

If everyone remembers textbooks on radio engineering or Rothhammel well, then an inverted vee (dipole) has a figure-of-eight diagram. Those. there are deep gaps. And if you change the position of the blades, swap one pair (move the blades of one antenna, for example, at an angle of 90 degrees), then the diagram begins to approach, so to speak, a thick sausage. But the most important thing is that the dips disappear, and the diagram is “rounded up”. With a dipole, it is enough to change the angle between the halves. And if we make this angle at the wave dipole equal to 90°, then with some stretch the radiation diagram can be called circular.

Bandwidth

As a rule, there are two classes of antennas: narrowband and broadband. It is very important that good matching and a given gain are maintained in the operating frequency range. The antenna bandwidth should not change when the transmitter or receiver changes frequency. Narrowband antennas include all simple resonant antennas, as well as directional ones such as “wave channel” and “square”. As an avid telegraph operator, I am quite satisfied with antennas with a bandwidth of 100 kHz, but there are generalists who love SSB, so antenna manufacturers are trying to provide a bandwidth equal to the width of amateur radio sections. For example, a “wave channel” antenna for the amateur radio range of 14 MHz must have a bandwidth of at least 300 kHz (14000 - 14300 kHz) and, moreover, good matching in this frequency band. Broadband antennas are distinguished by a large frequency range, in which the operating properties of the antenna are preserved, many times superior to resonant systems in this regard. These include log-periodic and helical antennas.

Efficiency factor (efficiency)

Part of the power supplied to the antenna is radiated into space, and the other part is converted into heat in the antenna conductors. Therefore, the antenna can be represented as an equivalent load resistance consisting of two parallel components: radiation resistance and loss resistance. The efficiency of an antenna is characterized by its efficiency or the ratio of the useful (radiated) power to the total power supplied to the antenna. The greater the radiation resistance in relation to the loss resistance, the greater the KGID of the antenna. It is quite obvious that good electrical contacts and small ohmic resistances (thickness of the elements) are good.

As you can see, this parameter interests us last and is not the main one. (God forbid you think that you don’t have to worry about its bad value. If the SWR is more than two, this is bad). If the antenna is tuned to resonance and during the setup we compensated for its reactivity and matched it with the power feeder in terms of resistance, then the SWR will be equal to unity. Just do not use the device built into the transceiver as an SWR meter. It's more of an indicator. Plus, the autotuner does not always turn off. But we want to know the truth. 🙂 And don’t forget about symmetry (see above). It is known that it is possible to power antennas with a coaxial cable of any length, which is why it is an asymmetrical coaxial cable, but in the case when two antennas are powered via one cable, it is better to make sure that for both calculated frequencies the cable length is a multiple of a half-wave.

For example, for a frequency of 14.100, the cable length should be:
100 / 14.1 x 1; 2; 3; 4, etc. = 7.09m; 14.18m; 21.27m; 28.36m, etc.

For 21,100 MHz respectively:
100 / 21.1 x 1; 2; 3; 4, etc. = 4.74m; 9.48m; 14.22m; 18.96m; 23.70; 28.44, etc.

Usually people consider the minimum feeder length to be a priority, and if we calculate slightly longer lengths, we will see that for the 15 and 20 meter ranges the first “multiplicity” will occur with a cable length of 14.18 and 14.22 meters, the second, respectively, 28.44 meters and 28.36 meters. Those. the difference is 4 centimeters, the length of the PL259 connector. 🙂 We neglect this value and have one feeder for two antennas. Calculating the “multiple length” of the feeder for the 80 and 40 meter ranges will now not be difficult for you. If we have not forgotten about balancing, we can now tune the antenna with confidence that the feeder does not introduce any interference into the purity of the experiment. A very good option is two double Inverted Vs on two masts: 40 and 80 + 20 and 15 meters. With this option (well, also GP at 28 MHz in case there is a passage), the EN5R goes on almost all expeditions.

Well, now we are armed with theoretical knowledge about the properties of antennas and can adequately perceive advice on their implementation and configuration. Of course, everything is theoretical, because you know better on the spot. The most popular antenna among radio amateurs is the dipole. So, the initial conditions: we can raise and lower the dipole within half an hour and many times a day. Then, most likely, there is no point in wasting time on pre-setting it on the ground: this will not be difficult to do for it to work at gimbal height. From preliminary theoretical knowledge, you only need information that the operating frequency of a dipole near the ground will “go up” by 5-7 percent as it rises. For example, for the 20-meter range this is 200-300 kHz.

To tune into resonance with the operating frequency of a conventional dipole, you can use (in addition to the lower-cut-raise system) either a sweep generator (many know this device under the name GKCh), or a GIR, or, at worst, a GSS and an oscilloscope. It is clear that if there are no such devices, then you will have to adjust the dipole blade to resonance using an ordinary field indicator, or as it is also called - a probe. This is an ordinary dipole with a length of blades no less than ten times less than the estimated length of the antenna itself, connected to a rectifier bridge (better on germanium diodes - it will respond to lower voltage), loaded on a regular pointer instrument - a microammeter with a maximum scale size (for better it was visible). It would be better if the probe has a circuit (filter) for the operating frequency, so as not to tune in to your neighbor’s mobile phone, and with an amplifier. For example this one. It is clear that we adjust the length of the dipole to the maximum of its radiation at the operating frequency. The minimum SWR in this case should be formed automatically. If not, remember about symmetry. If it doesn’t help and the SWR value is still high, you’ll have to think about matching methods. Although this happens very rarely.

The next most complex composition is several dipoles over one cable. Well, read about the cable above, but about the canvases you should know the following: to minimize the influence of one on the other, they should be stretched at an angle of 90 degrees. If this is not possible, then after correcting the length of one, you will most likely have to adjust the other as well. Several inv V. on one cable - the option described above and differs only in that you can “trim” the SWR to the minimum value by adjusting the angle of inclination of the blades in the vertical (towards the mast), which, of course, is simpler than making a matching device and even simpler than another adjusting the length of the fabric.

So, it turns out that a sequence of actions must be performed - first the antenna is tuned to resonance, and then the minimum SWR is achieved in the required frequency band. All this is true for simple dipole antennas. And it becomes very complicated if the antenna is multi-element. In this option, you cannot do without special devices, since it is necessary to set up not only a system with several unknowns, but also to achieve well-defined directional properties.

Tuning includes measuring the main parameters of the antenna and correcting them by adjusting the linear dimensions of the antenna elements, the distances between the elements, and adjusting matching and balun devices. Advice: trust the experts. As the famous Belarusian shortwave operator Vladimir Prikhodko EW8AU said, “by tuning the antenna only by SWR, you can make a good matched load from the antenna for the output stage of the transmitter. It will work well in normal mode, only the antenna may have a poor radiation pattern, low efficiency, part of the power will be spent on heating the antenna elements and the antenna-feeder path, and the most unpleasant thing that can happen to a radio amateur is television interference.” .