After the antenna is installed, it must be configured at a minimum of the KSV value in the middle of the operating frequency portion or if it is assumed to work only at one frequency, according to the minimum value of the KSV at this frequency.
What is KSV? KSV - the coefficient of standing wave is a measure of coordination of the antenna-feeder path. It shows the percentage of power loss in the antenna. Power loss with different CWV values \u200b\u200bare shown in Table 1.

Table 1. Power loss with different QCV values

Figure 1. Connection diagram of the KSV meter

ATTENTION!!! PRAOP should allow your output power! That is, if the device is designed for the maximum power of 10W, and to supply 100W to the input, the result will be quite obvious in the form of smoke and quite touch the sense of smell. The switch must be put in the FWD position (direct inclusion). Turning on the transmission, you need to set the handle the pointer to the end of the scale. This makes calibration of the instrument readings. Calibrate the device is needed every time when the operating frequency changes. Next, when switching (when transmitted), the device is in the REF position, turn on the transmission and read the value of the KSV on the instrument scale.

Consider an example of an antenna setting on the average mesh frequency C (frequency 27,205 MHz) by changing the length of the pin. First, you need to measure the KSV value on 1 channel of the S. Mesh. Then on the last (40) Channel C. S. If the KSV value is greater than 3 in both cases, it means an antenna is incorrect, not designed to work in this range or has faults. If the KSV, measured on 1 channel, is greater than the CWV value on 40 channel, then the pin length should be shortened, if on the contrary, the pin must be lengthened (extend from the holder). We get up for 20 channels of the grid C, measure the CWS, remember its value. We unscrew the screws that lock the pin, move it by 7-10 mm in the desired side, tighten the screws that check the CWW again. If the pin is inserted to the limit, and the KSW is still high, it will have to shorten the pin physically. If the pin is put forward to the maximum, then you will have to increase the length of matching the coil. Install the pin in the middle of the mount. We bite 5-7 mm, measuring the CWS, we bite again. At the same time, you follow the value of the CWS decreased. As soon as it reaches a minimum and starts to increase, stop mocking over the pin and then adjust its length by changing the position in the antenna thus we find the minimum of the CWS.

Please note that the antenna needs to be configured only at the place of its final installation. This means that, transferred to the antenna to another place, it will need to be configured again.

If you received the CWS of about 1.1-1.3, this is an excellent result.

If you got the order of about 1,3-1.7, it is also good and nothing to worry about.

If KSV is 1.8 - 2, you should pay attention to the losses in the RF connectors (incorrect cutting of the cable, poor conversion of the central cable vein, etc.) for antenna such a level of matching will mean that it has problems with coordination, and She needs customization.

KSV 2,1 - 5 means a clear malfunction in an antenna or its incorrect installation. KSV more than 5 means breaking the central cable or in the antenna.

From another source

The length of the 50-ohm cable in the half-wave, the "half-wave repeater" mode (is true for cables with solid polyethylene insulation of the central core)

Number of half feet
Grid "C" Catch "D" Grid "C" & "D"

The average frequency MHz
27.5

Cable cut length
1 3.639m 3.580m 3.611m
2 7.278m 7.160m 7.222m
3 10.917m 10.739m 10.833m
4 14.560m 14.319m 14.444m
5 18.195m 17.899m 18.055m

Modern communications allow you to maintain contact at a distance, regardless of weather, cellular coating or type of terrain. This became possible due to radio waves of different frequencies. For correct operation of the device, you need to know how to adjust the radio. It is worth noting that the market presents a wide selection of devices focused on universal use or narrower specialization (automotive, hunting, railway radio stations).

general information

Any witch must be configured under a certain frequency. With incorrect configuration, amateur or professional apparatus will work with interference or incomplete power. The latest modifications of digital devices do not require special adjustments, as they have the function of automatic configuration. The remaining devices are divided into portable (portable) or stationary (automobile) ractions. The configuration of both modifications has its own nuances, although the general principle is largely similar.

How to set a portable type war?

Amateur portable radio stations operate in the range of 433-434 MHz. They do not need to register the center of radio frequencies, so they are quite simple to set up. If you plan to increase the power of the device, before purchased, find out about the possibility of using a removable antenna. Another important point is the aggregation of racies among themselves. To do this, it is necessary to set the same numbers and subcodes on each device.

After the specified manipulations, the selected devices will work simply with each other. To communicate, you just need to press and hold the call activation key. After the button is released, the device switches to the signal from another radio. An important point in the setup of the portable apparatus is the selection of an individual signal for identification (called). In his role, any digital or letter code, which has a unique origin for the selected communication system.

Antenna Setup

Consider general recommendations, how to adjust the portable type waters in the antenna. For accurate element correction, a special analyzer will be required. Alternatively, you can use the KSV-meter device. It will allow you to adjust the antenna to the minimum coefficient of a stable wave. Most often it is customary to be the optimal coefficient of 1.5 or less.

It should be borne in mind that the higher the CWV value, the greater the indicator of the transmission power loss indicator. Ideally, this parameter should approach one, but in practice it is almost impossible to achieve such a result. In case of exceeding the FCs of three units, it is quite realistic to deal with the transmitter cascade. From this we can conclude that the non-configured portable radios can quickly break.

Automotive modification

How to set up (fixed) type? It is first necessary to perform a number of mandatory procedures that will increase the efficiency of further configuration and will minimize the probability of a transceiver breakage during operation. The device under consideration is a stationary unit fixed in the vehicle cabin, and a remote antenna. It is the last element that plays a meaningful role when receiving and transmitting the signal. Therefore, it is necessary to know the basic rules for mounting the receiving remote device.

Installation of automotive antenna

It is not allowed to install an element for carrier parts, the best option will be the body. This will allow to protect the ether from possible losses to receive and transform the signal.

In addition, the following points are important:

• Try to install an antenna for the highest point of the body. This will increase the quality of reception.
• The operating part of the antenna is set at a distance of at least 500 millimeters from any parallel metal surfaces. This will make it possible to avoid the absorption and reflection of the incoming signal.
• Placing on the roof of the car has a definite effect on the coefficient of a stable wave. Therefore, fix this element after removing in the same position.

After carrying out the correct installation of the antenna, switch to its configuration.

Configuring antenna for stationary radio

To configure the stationary type channel, first conduct an antenna configuration. To do this, it is best to use a professional analyzer. If such is not available, the CSW meter is used. Works are carried out on a clean and smooth surface, far from metal or concrete interference, as well as other analogues of the 27 MHz range.

First connect the KSW meter. Then make measurements on channels and grids to display an extensive picture. Perform a CSW-meter calibration by setting a toggle on the front panel to FWD mode. On the radio, the Channel No. 20 of Modulation AM is exhibited. Then activate and hold the conversation key, while when the CAL regulator is clockwise by setting the instrument pointer to the extreme right position set.

Not the releasing button on the tangent, switch the KSV meter toggle switch to the REF position. Remove the data issued by the device. After finding a minimum of the CWS, adjust the antenna for the required frequency. If the limit is lower or higher than the required frequency, the antenna is shortened or extended, respectively. Measurements are repeated until the CWW coefficient reaches 1.5 or less.

How about the wave of truckers?

Consider this procedure on the example of the Sirio T3 MAG antenna (range of action within 5 km):

1. The antenna is mounted on the central part of the roof, after which the protective cap is removed, the adjusting screw is tightened until it stops.
2. Between the radio station and the antenna is set to the CSW meter.
3. The radio includes, exhibit the "long-range" mode (channel No. 15 per AM).
4. After pressing the tangents, the KSW adjustment handle adjust the arrow to the Set position.
5. Holding the tangent, translate the KSW lever to the REF position, the current value of the instrument is observed over the top scale. If the coefficient is above 1.5, with the help of the adjusting screw, the testimony is adjusted within 1-1.5.
6. The adjusting screw is fixed with the help of a lock nut, the cap is put on and re-check the testimony of the KSW.

Knowing how to adjust the dodaughter's warfare, it is necessary to take into account that these elements are narrowband. Therefore, the settings are better to perform on the main work channel.

"Megazet"

First, the radiation is translated into 240 channels using the AM / FM-ON combination. You can switch to the Russian grid by typing DW / M2-ON. Domestic frequencies end 0, European waves - by 5.

How to set up a war "Meg's"? You can do it yourself, having studied the instructions. In short, the following points can be noted:

• First include a radio station using the VOL / OFF handle and set the required volume of the sound.
• Through the SQ regulator, the noise suppression threshold corrected.
• Using the UP / DN switch buttons, select the desired channel.
• To configure the transmission mode, the PTT regulator is retained, they speak the microphone at a distance of 50 mm.
• To receive the tangent and listen to the received message, adjusting the volume and level of noise cancellation.

"Baofeng"

Next, consider how to configure Baofeng's walking. By default, the operating frequency of the device is 2.5 kHz. General settings are identical for portable radio stations. Below are the device programming methods.

Simplex channels:

• Transition to VFO A.
• By pressing the BAND button, select VHF mode.
• The menu pick up '27' and press MENU.
• Then use a free memory cell, which is searched for using the UP / DOWN buttons.
• The selected frequency is confirmed by repeatedly pressing the menu key.
• For exit - Exit.

Channels with a repeater shift:

• Transition to VFO A. Mode
• Select UHF or VHF using the Band key.
• Select the receiving frequency.
• The menu find '27', then back in the menu.
• Looking for a free memory cell, as in the previous case.
• The "Menu" button confirm the selection.
• Press EXIT.
• Then they enter the menu again, select '27', double-click "Menu".

Finally

The above is considered how to adjust the radio. The wave should be chosen, depending on the type of device, as well as the country where the device is used. Antenna plays an important role in the configuration of portable and stationary radios. Therefore, its installation and configuration should be paid to special attention. If the device is adjusted correctly, you can unhindered to communicate with the respondent at a distance specified in the instructions for the device.

There are many portable and automotive radio transmitters in the modern market. Among them, you can easily choose the option that best suits your requests. It is worth noting that the digital modern models are configured automatically, but also the price of them is an order of magnitude higher than the analogues considered.

Often the client, especially if he buys a warden for the first time, begging at the mention that the antenna needs to be configured to use the radio, namely, setting up KSV antenna. What is KSV? This term man, far from technical subtleties, is low and sometimes scares. In fact, everything is simple.

What is KSV? The antenna setting is performed using a special device - the KSW meter. It measures the standing wave coefficient and shows the power loss in the antenna. The smaller this value (CWS), the better. The perfect value is 1, but in practice it is unattainable due to the loss of the signal in the cable and connectors, the working is considered to be 1.1 - 1.5, permissible - values \u200b\u200bfrom 2 to 3. Why are valid? Because with too much the value of the KSW, your antenna begins not so much to emit a signal on the air, how much to "drive" it back into the radio. And what does this mean and what it is bad, you ask? First, you lose in the range of communication, since the effectiveness of your "Warning-Antenna" system is reduced. Secondly, the weekend cascades of the radio station are overheated, up to a possible failure. That is why it is important setting up an antenna CWV after installation. One of the inexpensive KSW meters is the SWR-420 or SWR-430 manufactured by Optim. It can be used with the radio stations of the 27 MHz range having the output power of the transmitter to 100 W. Measurement error is no more than 5%. Using this device, you can achieve the values \u200b\u200bof the CSW \u003d 1.1 - 1.3, depending on the type of the selected antenna (mortise or magnetic) and its location. But it is not necessary to dwell on it. 1.5 - quite working and safe meaning.

How to produce configuring the CWS of the Range Sat Antenna? The antenna is installed on the car body, it is desirable to the highest point. The installation site should be chosen carefully, since the antenna will be in it constantly. When installing a mortise antenna, a normal contact of the antenna (or bracket) with mass and carefully monitor so that there are no short circuits in the cable and the cable connection points to the antenna and the radio. It is important to understand that the body of your car is also an antenna element, so it is impossible to refer to the place of installation and the quality of contact with the mass.

The KSW meter should be connected to the radio station through tX connector, connect the antenna to connector Ant. And choose the passage of the passing power level. To calibrate the device, you must set the switch to the position FWD., enable the transfer radio station on the desired channel and set the indicator arrow SWR. to extreme division SET. Red scale. After that, the device is ready for measurements. To check the CWS on the current channel we translate the switch to the position Ref. (The radio station continues to work on the transmission) and look at the indicator of the indicator on the top scale, this will be the actual value of the CWW. If it lies in the 1-1.5 interval - the setting can be considered complete and successful. If it comes out of this value, you begin to select the optimal value. To do this, first find the minimum CWW value on different channels or even grids. We are guided by a simple rule: if the KSV increases with increasing frequency, the antenna must be shortened if it decreases, then lengthen. By reloading the locking pin screws, move it to the desired side, tighten the screws and check the instrument readings again. If the pin is inserted to the limit, and the KSW is still high, then you will have to shock the pin physically by biting. If the pin is put forward to the maximum, then you will have to increase the length of matching the coil (in practice, in this case the antenna is easier to change).

In Beloyarsky, Beloretsk, Upper Salda, Glazov, Gubkinsky, Kamensk-Uralsky, Kachkanar, Korobalovo, Krasnouralsk, Kungur, Kushva, Langepas, Nevyansk, Priobye, Raduzhny, Salavat, Strezhevoy, Tuymazy, Urai, Mezhdurechensky, Nadym, Ozersk, Pioneer , Purovsk, Buzuluk, Pelos, Shock, Prokopyevsk, Purpe, Yugorsk, Seversk, Serov, Sibay, Solikamsk, Dry Log, Tchaikovsky, Chusovoy, Oktyabrsky, Simferopol, Tobolsk, Ishim, Kogalym, Sadrinsk, Nyagan, Sarapul, Yuzhnouralsk - KIT .

Delivery of the KSW meter is possible to any settlements of Russian Post by cash on delivery or EMS by mail, for example: Alapaevsk, Artyomovsky, Asbesto, Astana, Aktobe, Akasi, Atyrau, Aksai, Almaty, Balkhash, Baikonur, Balakovo, Berezovsky, Bogdanovich, Top Pyshma, Zarechny, Ivdel, Irbit, Kamyshlov, Karpinsk, Karaganda, Kirovgrad, Kostanay, Kokshetau, Kyzylorda, Semey, Krasnoturinsk, Krasnoufimsk, Forest, Lower Salda, Lower tour, Novouralsk, Pervouralsk, Polevskoy, Revda, Severouralsk, Syver, Nutcan, Taut Vereshchagino, Nytva, Lysva, Krasnokamsk, Spirit, Poland, Chernokamsk, Gornosavodsk, Dobryanka, Gremyachinsk, Kudymkar, Gubakha, Yaiva, Vikulovo, Bright, Lower Tavda, Yalutorovsk, Kaskar, Kazan, Borovsky, Petropavlosk, Romashevo, Golyzhamnovo , Pavlodar, Tarmann, Taldykorgan, Zhezkazgan, Vinzili, Great Sorokino, Bogandinsky, Uporovo, Uralsk, Ust-Kamenogorsk, Shymkent, Taraz, Otutinskoye, Berdyuzhye, Abat, Antipino, Issue, Turrtas, Norilsk, Salekhard, Rkut, Votkinsk, Ekibastuz.

Company Realradio Makes up novelties in the field of radio and glad to offer the most modern means of communication to perform any tasks. Professional radio communication - our specialization!

Nowadays, the CB BB (CB - Citizen Band) radio communications acquires increasing popularity in the environment. It is especially relevant for those who are often moving over long distances. These are truck drivers on trucks, travelers, and other people whose activities or rest are associated with frequent roads.

Modern radio stations of the 27 MHz range are very diverse in their dimensions, specifications and layout. The devices with a remote front panel are also common. In some designs, all controls and indications are located on the tangent. In other words, the industry produces products capable of satisfying the most picky buyer.

We will talk about how to install and connect a radio station in a car, as well as affect the theme of the antenna settings.

Table of contents:

Install antenna

Installation Tools in the car is customary to start an antenna mounting. Curling antennas require good contact with the metal (body) metal metal. This is necessary for the correct radiation chart. The location of the bracket additionally needs to be protected from corrosion by any preservative. The usual Movil is suitable. If possible, the antenna pin should be placed as close to the roof center. This applies to the antennas with a magnetic base.

Please note: accommodation on the trunk lid or the rear bumper will lead to an infallible work and distortion of petals of the radiation pattern. This means that the maximum strengthen will be incorrect, and the antenna will effectively work only in certain directions. For example, if an antenna with a magnetic base is on the back of the roof of the car, then the maximum efficiency (both acceptance and transmission) will be directed towards the front of the car.

Antenna cable placement

The laying of an antenna cable should be started from its roof laying. In order not to spoil the paintwork, it is better to purchase special self-adhesive sites. The cable will lie on them without touching the roof surface. At the same time, it should not be strongly stretched.

Inside the passenger car lounge, the cable is advisable to start through the lid of the trunk (or the fifth door of the hatchback), and not through the side doors. Inside the cabin, the cable should be stretching under the trim, while it is undesirable to secure it to the footage of the standard electrical wiring. It is better to have it separately. Mounting cable should be fixed using nylon screeds.

Important: It is impossible to allow strong bends, twisting and deformation of the cable.

The length of the cable supplied with the antenna is usually 3.5-5 meters, so take care to have enough it. It is not recommended to extend or trim the cable - this can lead to a violation of its coordination with an antenna and worsen its technical characteristics.

Placing and connecting the radio station

Placing the device should be subject to the fact that it will not prevent access to the controls, limit the visibility and distract the driver. This should ensure the ease of control of the device. If you find a suitable place to install it is difficult, then preference should be given to the apparatus with a remote front panel. Place small sizes The panel is always easier, but the block can be fixed in any convenient location. The only requirement is - you can not put it in places where it will be heated from various sources.

All radio stations are designed to power a voltage of 12-13.8 V. Power wires, it is advisable to vote from the battery. Moreover, both positive and negative. It will save from the occurrence of unwanted interference, which the range of 27 MHz and so scored, especially in the conditions of the city. The feed cable, which is included in the kit already contains a filter of interference and fuses. If there is a need to lengthen the wires, it is most preferable to use a soldering and insulation of a shrink tube. It will not be superfluous to hide them into a plastic corrugation.

The power cable gasket is made neatly, without twisting and deformations using nylon screeds for fixing.

Please note: Do not feed the radio station from the standard cigarette lighter, and especially from lighting plaffers, because Their wiring may not withstand the current consumed by the transmitter. It is impossible to treat it frivolous, as there are many cases of car fire.

Also installed in the cabin an additional power switch. It is easy to implement using a relay and buttons, or purchase a ready-made switch. The latter should be designed for current at least 20 A. Put such a switch anywhere, but remember - it must necessarily be fixed, and not hang on the wires.

Antenna Setup

The antenna setting is a very important procedure, and it is not necessary to bypass it. This will depend on the efficiency of work and quality of radio communications. Best of all, if this is done by a specialist, but if there are minimal equipment, some types of antennas can be configured on your own.

The antenna setting is to bring it into the resonance with the frequency of work. The frequency on which drivers work, 27.135 MHz (channel №15).

To configure, you will need:

• The KSW meter is a device for measuring the coefficient of standing wave. Simply put, this parameter indicates the quality of the antenna and radio stations.
• cable segment with "UHF-MALE" connectors at both ends (manufactured independently) no more than 0.5 m. Next, we will call it "adapter".

We carry out the measurement according to the following algorithm:

1. we connect the antenna connector into the Nest "Ant" of the CSW meter;
2. we connect the adapter to the antenna jack of the radio station, and the second end - to the "TX" jack of the KSV meter;
3. turn on the radio station and set the frequency of 27.135 (or channel No. 15);
4. press the "PTT" button on the tangent and see the testimony of the arrow of the KSW meter

Important: Never turn on the transfer radio station with a disabled antenna!

Normal significance lies in the range of 1-2, the closer it is to one, the better. If the value is normal, disconnect the KSW meter, connect the antenna to the radio and use on health.

If the value is above 2, the actions are as follows:

1. write down the obtained value of the KSW;
2. exhibit frequency 27.405 (or channel number 40)
3. press "PTT" and look at the instrument readings.

If KSV has become less, this suggests that your antenna has a resonance at higher frequencies and the pin must be done a little longer. To do this weaken the pin mount to the base (usually 2 screw under the hexagon) and push the pin slightly. It must be remembered that in this case the possibility of adjusting is small.

If the KSV became greater, then this means that the antenna resonance lies below the frequency 27.135. In this case, you need to shorten the pin for about 1 cm and measure the KSW again. If it has become less than the value that was obtained during the first dimension, then you are on the right track. So a gradual decrease in pin length can be achieved excellent readings.

Before starting the radio station, carefully examine the attached instructions.

The article is written for beginners, those who are first time to set up an antenna to work on the channel you need (frequency). Who has repeatedly engaged in the antennas setting, are unlikely to find something useful for themselves in the article.
The article describes the main points of the adjustment of simple single-band antennas - automotive mortar, on a magnetic base, base 1/4 GP, 1/2 (half-gun), 5/8 (five eighth).

What you need to configure antenna

KSV-meter
The device that shows the ratio of the straight line (coming from the radio station to the antenna) and the reverse (reflected from the antenna) waves in the cable.
Indirectly, this device shows that the outlet wave resistance of the radio station is equal to the resistance of the cable, and it is equal to the antenna resistance. The fact that such wave resistance is and how it differs from the one that shows the usual tester, you can read in the article :.
The KSW meter (KSW meter) can be purchased (the price of the question is about 1000 rubles) or for a while to ask for anyone from acquaintances, who has it.

Radio station
The CSW meter does not work without a radio station.
The more "grids" is in the radio station than the broader frequency range can be rebuilt the radio station, the easier it will be to configure the antenna to the desired frequency (channel).
Having a radio station with 40 channels for 27 MHz, you can adjust the antenna, but it is very difficult, with a radio station that has 400 or 600 channels, it is much easier to do.

Roulette or ruler
It will be necessary to measure the antenna web and determine how many centimeters to shorten or extend.
In principle, you can do without a roulette or ruler and performs the setting just step by step, by slightly shortening or extending the antenna canvas.

Basic provisions when setting up antenna

Antenna must be configured at the place where it will then stand.
That is, an antenna must be configured in those conditions in which it will further be operated, especially if at a distance closer than 2-3 wavelengths (wavelength \u003d 300 / frequency in MHz (for 27 MHz wavelength of approximately 11 meters)) there are some Conductive items parallel to the antenna canvas.
If it is a basic antenna, then it is already necessary to prepare a mast for it, which allows you to shoot and install an antenna, raise and lower it all for configuring and maintenance.
If it is a car antenna, then the car should be phased so that there is exactly the situation that there is exactly the situation that will be when driving on it at the time of the radio station, that is, at a distance of the order of meters 5-10 stood other cars, but on the other hand there should be no There are walls of reinforced concrete houses, garages, you can not stand inside the iron garage or hangar. At the time of measurements, the doors must be closed when setting up the car. It is not necessary to stand next to the car, the human body absorbs radio waves and thus makes losses, affects the operation of the antenna.
At a distance of 2-3 wavelengths from the antenna should not be moving conductive objects.
All device connections must be reliable.
You should not keep everything "on the weight", pressing the contacts to contact somehow, as the stripped pieces of the cable, which are about to fall out of the connector or closed.
Reliable connections are needed that the testimony of the device does not change as they do, they did not swam and were repeated. If the testimony is not repeatable, it is no longer an instrument reading, but the weather on Mars at the time of eating Snickers and focus on such indications is impossible.

How to use the KSV meter

We connect the cable to the antenna, the other end of the cable to the KSW meter, to the "Ant" connector, connect the "TRANS" KSV meter connector to the antenna connector of the radio station.
Turn on the radio station and set the frequency on which we will perform the measurement of the CWS.
If there is a Switch switch SWR / PWR to translate to the SWR position.
Switch on the "FWD / REF" XV meter to the FWD position.
Click on the transfer on the radio stations and install the arrow to the end of the scale protruding from the CWW meter. We release the transfer.
Install the "FWD / REF" switch to the REF position.
Press the transmission and count on the indicator the testimony of the KSW. On most of the KSW meters, the less the arrow to deviate the shorter the shorter, if it does not deviate at all, then the KSW \u003d 1 or the device is dead. If at all frequencies, in the reference position, the arrow is not deviated, then either you instead of the antenna connected a good equivalent of the load, or the device died, but we will not be about sad.

Antenna Setup - step by step

We connect everything to measure the KSW, as mentioned above, the antenna in the working position.
- We set the highest frequency on the radio station, which is capable of issuing a radio station, for example, the G channel 40 (more precisely, see the instructions for the radio station).
- Measure the CWW, moving down the frequencies of approximately 20 channels (200 kHz), remember, at what frequency (channel, grid) was a minimum of CWS and which CWS was in a minimum.

Now there are several options:
KSW everywhere large, device "scale".
Or you do not use the KSV meter or you have a break in the cable or antenna.

KSW smoothly, as the frequency decreases, falls, but we did not reach the minimum.
Your antenna is too long. Need to shorten. In short, it is worth remembering the Gold Rule: "Some seven times, a rejection once." Shortening to join back in the history of cases is impossible, so we shorten on a little bit, for antenna Si-bi range of 27 MHz a little bit, it is about 1 centimeter, for LPD or PMR antennas of the range of 433-446MHz a little bit it is 2 millimeters.

KSV as the frequency decreases increases.
Your antenna is too short. Antenna needs to be lengthened. As far as exactly - better than 20 percent, and then crushing.

The KSW as the frequency decreases fell, at some frequency it became minimal, and then, as the frequency decreases further, it began to increase again.
This is the most frequent occasion.
It means such a behavior that everything is fine, the antenna works in the desired range, it remains only to adjust it to the desired frequency (channel).
If you have this case, it is advisable to find exactly on what channel is the minimum of CWS.

If the frequency on which was at least the CWS lower than you, then the antenna should be a little bit to shorten, literally 5 millimeters, if we are talking about the range of 27 MHz, after each shorting to watch where the minimum of the CWS is now, and shortening so far as long as the minimum CWS will not be in the required frequency.

If the frequency on which was the minimum of the KSW higher, the antenna needs to be lengthened.

What to do if the minimum CWW is in the desired frequency, but this is the minimum value is still big

This suggests that the antenna works not entirely as they conceived by the manufacturer or the rubbish antenna, however, you do not need to immediately about sad.
If this is a car mortise antenna, then maybe it "lacks the masses", that is, contact with a lot of bad.
If it is a car antenna on a magnet, then it can also be "missing mass", for example, the paint layer is too thick.
Or your car antenna is located where you should not put - next to the elements of the metal trunk on the roof, next to the extra light that you hung on the trunk, you generally lived on a hood or trunk, bumper or wheels disk.
Maybe you secured the mortise antenna on the aluminum trunk's aluminum clamps, which you have on the roof, but the trunk was not aluminum and plastic or does not have reliable contact with the mass of the car, or not long and widely, which would perform the role of the mass for the antenna.

If an antenna is on a magnetic base, try searching for another place where it will "make it", try with the roof corner, in the center of the roof, from another corner.
Radio frequency currents flow not quite as a constant current, where the tester will show excellent contact, for radio frequency it may be a "bottleneck".

If the rowing antenna, look, whether you read the place from the paint, where the contact of the mass of the antenna is attached.
If the mortise antenna you fastened on the trunk or some fasteners on the drain, try to improve contact with the mass. There were cases when the author of the article took 2 pieces of the wire 0.5mm thick without isolation, wound on the bracket on which the mortise antenna hung on the drain or trunk was fixed, threw them into different angles of the roof of the car on the waterproof and CWS with 3 decreased to 1, then There is an antenna started to work perfectly (naturally the signal on the air was also improved).
Throw extra wires, tear paint and then pour the sealant or search for other ways to improve the mass or installation point - to solve you, this is your antenna and your car.

If you do not have a car, but the basic version of the antenna, then the treatment here is actually exactly the case, namely: it may need more "masses", and maybe you need to climb an antenna design with a soldering iron.
To begin with, we are convinced that there is enough mass - the bottom of the base, it is the main opposition, the mass for the 5/8 antenna (five eighth) and 1/2 (half the wave) should be at least 1/4 of the wavelength, that is, for 27 MHz it is About 2 meters 75 centimeters. More - better; Less - it will have to lengthen the wire thrown on the roof.
Although sometimes it happens that everything is done well, and the antenna is not configured, so it was a familiar author of the article, 1/2 did not want to tune. It seems in the frequency, and the KSV is not 1 and not even 1.2 and not 1.5 - it turned out someone "climbed into the antenna" to it and cut off the coil of the coil installed inside the antenna.
It is also likely to prevent your basic antenna near the stretched optics of your provider or a collective antenna mast.

How much to cut and what is the ruler?
The dimensions of the antennas depend on the frequency linearly.
In case the antenna is full-size, then how much it needs to shorten or lengthen, to get into the desired frequency, directly depends on the ratio of the current frequency, where it resonates and the desired frequency, where we would like an antenna to resonate.
I will explain on the example:
We have a quarter, then let it be 267 centimeters, it resonates (CWS minimally) was at a frequency of 27.0 MHz (4 channel sect c), we want an antenna to earn at 27.275 MHz.
We consider the difference in frequencies:
27.0 / 27.275 = 0.9899175068744271
We multiply to this to the current length of the antenna:
267 * 0.9899175068744271 = 264.3
And we get the length that an antenna should have to earn at 27.275.
Calculate how much cut:
267 - 264 \u003d 3 cm.
But!
It is not necessary to cut at once on 3 cm. Do not forget, the antenna is not only a pin, it is also a counterweight. It affects everything.
So you can reflect the order of the first cutting - if 3 cm, or 5 mm.
Next, act step by step.
For the example above, you can cut off 1.5 cm, it is again to find the resonance, and on the basis of the result obtained, you move further.

Lastly, although it was probably necessary to write the first:
Basic rules for installing antennas
The antenna must be put not closer to one wavelength to other conductive subjects, especially those that will be parallel to the antenna.
The higher the antenna is installed, the better.
It is clear that for automotive antennas at 27 MHz, these rules are simply impossible to observe, according to this, automotive antennas are compromise, for this not to demand wonders from them.

If you still have no time, there is no desire to understand the wisdom of measurement of the CWS, search for a CSW meter, customize the antenna yourself and you are in Novosibirsk, you can contact for example here: