Automotive C-Bi MegaJet antennas. MegaJet Car CB Antennas Which Antenna is Best for MegaJet 300

Introduction

1.Brief specifications and distinctive features

2. Main features and functions

3. Controls and displays

4. Main modes

5. Small-sized LCD display

6. Installation of the radio station in the car

7. Installation and configuration of the car antenna

8. Rules for using the radio station

INTRODUCTION

Thank you for purchasing the MegaJet MJ-300 car radio. The MegaJet MJ-300 radio station is easy to use and will provide you with safe, efficient and reliable communication. Please read these instructions carefully before using. The information presented here will help you get the most out of your walkie-talkie.

The Megajet MJ-300 radio station belongs to the class of equipment available for civilian radio communication of the range.

1. SAFETY INFORMATION

The following precautions must be observed when operating, servicing, and repairing this device.

Repair and maintenance of the MegaJet MJ-300 radio should be carried out by qualified personnel in a specialized service.
Do not modify the design of the radio station!
Turn off the radio before entering an area where explosive or flammable substances are located.
Do not use walkie-talkies with a damaged antenna. There is a high risk of burns if a damaged antenna touches body parts.
To avoid creating electromagnetic interference or compatibility issues, turn off the radio in areas where it is required, especially where there are information signs reminding you to do so.
Turn off radio before entering blasting area.
For vehicles with airbags: Do not place the radio in the deployment area of ​​airbags or directly on their covers.

Functionality of the radio station MegaJet MJ-300

Compact design
Microprocessor SAMSUNG 3P9228AZZ-QZR8
Separate frequency synthesizer on the LC7152N microcircuit
Front panel with small LCD display
Speaker with increased power (8 Ohm, 3 W, square 76x76 mm)
Robust PTT with electret microphone
Scan mode (SCAN)
Emergency tuning to channel 9 (CH9)
External loudspeaker connectivity

1. BRIEF TECHNICAL CHARACTERISTICS OF RADIO STATION MEGADZHET 300

2. KEY FEATURES AND FUNCTIONS

FUNCTIONS

• Two kinds
• SC scan button
• Emergency call channel 9 (changeover)
• UP / DN pushbutton control
• Non-volatile memory of settings
• Adjustable automatic system noise reduction
• Built-in input attenuator

CONTROL

• Volume control with power switch
• Squelch threshold adjuster
• Channel up / down buttons
• Channel 9 emergency call button
• Channel scan button

LCD DISPLAY

• CHANNEL / GRID / SCAN display
• TX / SC / / L / H mode indication

3. CONTROLS AND DISPLAYS

Description of controls

1. 4-pin connector for push-to-talk (headset)
2. Power on / VOL / OFF volume control.
3. Adjuster for the threshold level.
4. LCD display LCD. All current operating modes of the radio are displayed.
5. Button for selecting the type of modulation AM / FM (AM / FM).
6. SC scan button. This button can be used to search for a channel with heavy traffic. After pressing this button, the channels are scanned upward. When a signal is detected, scanning will be paused. When the reception is stopped, scanning resumes after 10 seconds. When you click on the transmission, scanning will be stopped.
7. Button to quickly switch to the emergency channel CH9 / switch. This button is designed to quickly switch to the 9th channel when a emergency... If the radio is in multigrid mode, this button switches the grids. A long press (more than 1 sec) turns on the built-in attenuator to attenuate the received signal. In this case, the symbols "Lo" will be displayed on the screen. When the CH9 button is held down again, the mode is turned off, and the symbols "Lf" will be displayed on the screen.
8. Channel up button UP
9. Channel down button DN

Description of the connectors on the rear panel of the radio

SC - Scan. When “SC” is displayed, the receiver is in auto scan mode. To use this function, turn on the power of the radio and set the required volume. Adjust noise reduction. Press the “SC” button and scanning will start. The LCD will show “SC”. When a channel is detected, the signal in which exceeds the squelch level, scanning stops and resumes again after the signal disappears, until the PTT or the “SC” button is pressed.

M, L, H - in multigrid mode indicates grids C, B, D, respectively.

5 - displays the activation of the frequency shift mode by -5 kHz (Russian standard)

6.INSTALLATION OF THE RADIO STATION IN THE VEHICLE

The MegaJet MJ-300 radio station is intended for use in vehicles with a 12-volt battery and a negative grounded. should be sufficient both for powering the radio station and for the needs of automotive electricians.
Before installing the radio, check that your car complies with this requirement.
A mounting bracket and a microphone holder are used to mount the radio in a car.

PLACE OF INSTALLATION OF THE SI BI RADIO STATION

The radio station is installed in the car in such a place that its use does not create inconvenience and does not distract the driver from driving. The best place for this is under the dashboard of the car.

Attention: Make sure that when choosing a location for the radio station, it does not interfere with the driver and does not impair access to vehicle controls. Observe safety requirements when laying the connecting cables. If the radio or connecting cables are not conveniently located, you may lose control of your vehicle.

MECHANICAL WORKS DURING INSTALLATION.

Step 1. Using caution, use the mounting bracket as a template to mark the mounting holes under the dashboard. Use an awl or other sharp metal marking tool to mark the drilling sites.

Step 2. Drill two 3mm holes for each mounting plate screw. Fasten the bracket under the dashboard with the supplied self-tapping screws (see Fig. 1). Drill holes with particular care to avoid damaging the connecting harnesses and electronic devices located under the panel.

Fig. 1. Mounting the radio with a mounting bracket.

INSTALLATION OF THE RADIO STATION.

Step 1. Insert the radio into the mounting bracket until it aligns with the latches (see Figure 2). Adjust the tilt angle of the radio housing to the optimal angle for easy access.

Step 2. Fasten the clips of the radio, while providing a place for connection external cables to the back of the radio.

MICROPHONE HOLDER INSTALLATION.

Near the radio station on dashboard drill two holes to install the microphone holder arm. Fasten the holder with the two supplied 10mm self-tapping screws to the radio.

EXTERNAL SPEAKER CONNECTION (not included in delivery).

The rear of the radio has a jack for an external speaker "EXT-SP". Plug in the plug from an external speaker, this will disable the built-in speaker.

POWER SUPPLY CONNECTION.

Since the MegaJet MJ-300 radio station is equipped with a power filter to exclude interference from the engine ignition system, it can be connected to the vehicle board at any point. It is best to use a twisted pair wire to reduce interference.

Step 1. Disconnect the power cables from the battery terminals to avoid short circuits that may occur when connecting power to the radio.

Step 2. Securely connect the black “negative” wire from the radio directly to the vehicle body. For the best performance, the radio requires reliable contact with the metal of the body.

Step 3. Connect the red “positive” wire from the radio with built-in fuse holder to the fuse box (“cigarette lighter” or directly to the positive terminal of the battery). Usually the most convenient point for connecting a radio is the fuse box. You can connect the power cable to the ignition switch contacts, in which case the radio will turn off automatically when the ignition is turned off, which will prevent accidental battery discharge.

Step 4. Reconnect the power cables to the battery terminals. Connect the power cord plug to the radio cable connector.

7. INSTALLATION AND CONFIGURATION OF CAR ANTENNA

In general, there are two types of antennas for mobile CB radios - a full-length 1/4 wavelength rod (2.75 m) and a shortened matched rod antenna (0.5 to 1.9 m). Due to the long length of full-size antennas on cars, shortened antennas are mainly used in various designs with attachment through a hole in the roof, on a bracket for a flange of a gutter or on a magnetic base (see Fig. 3).

Rice. 3. Typical locations for car antennas.

Antennas on a magnetic base have the advantage of being easy to retract into the car when parked, and the strength of the magnet ensures that it is securely held in place when bumping and moving at high speeds.

The antenna's directional pattern depends on the location of the antenna. When the antenna is installed in the middle of the roof, the radiation pattern approaches a circular one. If the antenna is installed on the right edge of the roof, then its maximum gain will be directed to the left of the vehicle axis. Placing the antenna on the rear rack will point the antenna diagram forward.

In fig. Figure 3 shows five typical vehicle antenna locations: (1) rear bumper, (2) back cover trunk, (3) flange for water drain, (4) hood, (5) roof.
For qualified advice regarding the choice of the type of antenna and the place of its installation, contact your seller.

The installed car antenna should be tuned to resonance at the center frequency. For tuning and periodic monitoring of the antenna and antenna cable, a meter is used, which is included in the circuit between the radio station and antenna cable with a separate adapter cable, minimum length. Various types antennas are tuned different ways, therefore it is necessary to read the instructions. As a rule, the tuning of the antenna, which at the point of location has a reliable galvanic (or capacitive - through the entire area of ​​the magnet) contact with the conductive underlying surface (the area of ​​the roof of the cabin), is carried out by decreasing or increasing the length of the pin. Try to keep the SWR as low as possible (one ideally) in the middle of your chosen frequency range (for example, between the two most frequently used channels). And if at the same time at the edges of the "working" range it is possible to obtain a VSWR of no more than 1.5, then your choice of channels is correct and the antenna is tuned perfectly.

Carefully follow the manufacturer's antenna installation instructions.

Attention! Never switch on the radio station for transmission, even for a short time, with an un-tuned antenna or “detuned” antenna, when reliable electrical contact between the cable sheath and the antenna “ground” with the conductive underlying surface at the antenna location is lost. This can lead to damage to the radio station and the electrical equipment of your car!

8. RULES FOR USE OF THE RADIO STATION

• Turn on the radio by turning the “VOL / OFF” knob clockwise. Set the required audio volume.
• Adjust the squelch threshold with the “SQ” knob as instructed in this manual.
• Select the desired channel with the UP / DN buttons.

Note: If channel re-tuning is not performed, note that emergency channel mode may be enabled. This mode is canceled by pressing the emergency button CH9 “Channel 9”.

TRANSMISSION MODE.

Press and hold the “PTT” switch on the microphone body. Hold the microphone body 5 cm from your mouth and speak in a normal, clear voice.

RECEPTION MODE.

Just let go of the PTT and listen to your correspondent using the volume and squelch controls for the best sound quality.

Description and Overview

MegaJet MJ-300T- continuation of the once popular model with increased power transmitter. FREE check of work upon purchase and FREE setup when purchased with an antenna.

Description of the radio station:

1.The appearance of the radio station

Car radio station MegaJet MJ-300 Turbo differs from the previous model MJ-300 by increased transmitter power AM-8 W, FM-16 W). The MJ-300 Turbo has a compact size (138x40x125) and a low weight - 1 kg assembly. The front panel conveniently located controls, thanks to which you can tune the megajet MJ300 turbo autoradio station for optimal operation. Thanks to the bright and comfortable backlighting of the front panel, as well as the LCD display, which displays the channel number and the level indicator of the RX / TX signals, it is convenient to work with the MegaJet MJ-300 Turbo CW radio station even in the dark.

The stamping quality of the plastic parts is very good. The front panel is simple, has a minimum of buttons and knobs, the indicator is small, but the MegaJet MJ-300 Turbo radio has some differences appearance from MegaJet MJ-100. The radio station is made on the technological platform “600” (modern multifunctional radio stations MJ-600 and MJ-600plus are produced on this platform). The longitudinal size of the body is only 125 mm, which allows you to place the radio in the limited space of any car dashboard. The radio station's tangenta is equipped with a high-quality electret microphone, a powerful 3 W speaker is responsible for the sound quality, and an external loudspeaker can be connected.

2. EquipmentMegajet MJ-300 Turbo

• Transceiver
• Tangenta with microphone
• Fuse power cable
• Mounting bracket
• User guide

3. The main declared functions.

• 135 frequency channels, including "holes"
• Ability to work in the Russian frequency grid (shift -5 kHz)
• Built-in input attenuator
• Channel indication
• RX / TX signal level indicator
• Adjustable spectral squelch
• Scan mode
• Emergency tuning to channel 9

Review of radio station Megajet MJ-300 Turbo

Megajet MJ-300 Turbo is designed taking into account the climatic conditions of operation in central Russia, which guarantees a long service life and stability of operation. MEGAJET MJ300 Turbo has good receiver sensitivity due to modern circuitry, and this is achieved by using a separate frequency synthesizer mounted on an LC7152N microcircuit with external digital control. This made it possible to expand the frequency range, improve the spectral purity of the signal and improve the stability of the operating parameters.

The design of the Megadget 300 Turbo radio station uses a liquid crystal display (LCD) of the Black Matrix type with memorization of the current mode and with additional illumination. Especially convenient when using the LCD display are the 10 mm channel number indicator, black numbers on an amber background. The information panel of the LCD displays the main functional parameters of the operating modes of the C-Bi radio station.

MegaJet MJ-300 Turbo is assembled on the basis of SAMSUNG processor 3P9228AZZ-QZR8 and uses frequency (FM) and amplitude (AM) modulation. The station is capable of operating on 135 channels in the Russian and European frequency grids and has a transmitter power of up to 8/16 W (AM / FM). The transceiver provides a channel scan mode and the possibility of emergency tuning to the 9th channel. Megadget 300 Turbo has a compact size and informative high-contrast liquid crystal display with backlight. In addition, the built-in attenuator of the input signal, the ability to work in "holes" and the non-volatile memory of settings should be noted among the distinctive features.

C-Bi radio station Megadget MZh-300 Turbo combines excellent functionality, good transmitter power and not a high price. You can safely call this model the best choice for out-of-town weekend trips. Compact size, low power consumption and ease of use, combined with a magnetic antenna * makes this model a good choice for everyone. The Megajet 300 Turbo radio is better adapted to the conditions big city, where high level interference and a large number of stations.

ATTENTION! It is forbidden to use the radio station without an antenna connected to it!

Among a wide selection of antennas, you can buy the one you need in the stores of the RADIOSILA company!

Radio station MEGADZHET MZH-300 TURBOcan be bought in our departments in Moscow , St. Petersburg , Yekaterinburg , Tyumen , Perm, Chelyabinsk, Ufa, Samara or order delivery to any locality in Russia: Kazan,Novosibirsk , Nizhny Novgorod , Omsk , Rostov-on-Don , Volgograd , Krasnoyarsk , Saratov , Voronezh , Krasnodar , Izhevsk , Ulyanovsk , Barnaul , Irkutsk , Novokuznetsk , Orenburg , Kemerovo and other cities.

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Compact and inexpensive Car radios cb range. This is the simplest, budget model in the line of walkie-talkies made on the basis of the megadget 600 platform.

The features of both this model and the entire line include: a frequency synthesizer on the Motorola LC7152N microcircuit (characterized by high stability, accuracy and purity of the generated subcarriers) and a digital microprocessor SAMSUNG control 3P9228AZZ-QZR8. As a result, a more stable and high-quality communication in conditions of high industrial interference.

This station differs from other models based on the "platform 600" by its low output power, small LCD screen and compact dimensions are quite typical features budget solution... The walkie-talkie can be recommended as an inexpensive and reliable solution for a taxi or delivery service with a short range

There is a version of the Megajet MJ-300 Turbo transceiver, which is distinguished by an increased output power of the transmitter to 18 W and the presence of an automatic spectrum squelch.

Megadget 300 radio stations are produced by several enterprises in Southeast Asia. The main external difference walkie-talkies made in China - blue display backlight.

Manual for MEGAJET MJ-300 (in Russian).

FEATURES OF MEGAJET MJ-300:

• Compact design
• TX / SC / FM / AM / L / H mode indication
• Speaker with increased power up to 3 W (size 76x76 mm)
• Adjustable automatic squelch
• Scan mode (SCAN)
• Emergency tuning to emergency channel 9
• External speaker connectivity
• Switching between AM / FM modes
• Button control of channels Up / Dn
• Display of channels, grid, scanning
• External speaker jack 3.5mm

Production - Republic of Korea (RKK company). Certified in Russia, 6 months warranty.

Equipment : radio station MEGAJET MJ-300, PTT with microphone, power cable, bracket, instructions.

Mode - "45 channels": press and hold the A / F button for a couple of seconds - the message SP will be displayed on the screen and the radio will switch to 45 channel mode, when pressed / held again, it will go back to 40 channel mode, and SF will be displayed on the screen.

Switching the Russian / European frequency grid in the MEGAJET MJ-300: while holding down the A / F and CH9 buttons, turn on the radio with the VOL / OFF knob. The screen will display "5". To return to normal mode, you need to repeat the specified operation.

Turning on the attenuator: press and hold the CH9 button for 2-3 seconds, the symbols "Lo" will be displayed on the screen. Pressing and holding the CH9 button again deactivates this mode and displays an "L" on the screen. An attenuator is used to stabilize the received signal to improve speech intelligibility.

Rating: 5 out of 5

Advantages:

Price quality reception stability

Disadvantages:

A comment:

I purchased this copy quite recently, I took it from my hands for a penny.
Tested as a hospital, with the simplest antenna.
The zone of confident reception with a wire at the antenna input (with an ordinary wire) is 7 kilometers.
It is a pity that there is no normal antenna, but from experience I am sure that it will confidently hold 20-25 kilometers. It is powered from 9 to 15 volts, it is very convenient with drops and not high-quality power supplies. (Unless, of course, you use it as a hospital)

In general, I am satisfied, I think the time will come in handy.

Rating: 5 out of 5

Advantages:

Convenient PTT, the walkie-talkie is easy to operate

Disadvantages:

Not found

A comment:

Working in a taxi as a dispatcher, I worked on Megadgetka. Excellent signal, transition to - / + from the main channel. Magnetic antenna. On New Year's holidays, drivers wound tinsel on the antenna, which greatly interfered with signal reception.

Rating: 4 out of 5

Advantages:

Simplicity in settings and work. The transmission / reception audibility is good. Clarity of speech transmission. PRICE!

Disadvantages:

Noise reduction in automatic mode the reception is very rude.

A comment:

I was going on a trip on the X-trail Vladivostok-Krasnodar and back. I read reviews, forums. I chose Megajet MJ-300 + Alan 145 cm on a magnet. I set it myself using a SWR meter. I figured out the controls very quickly. The trip was always included. I contacted subscribers to check the range of reception / transmission. On the plain, reception in normal weather conditions in summer is up to 10 km, transmission is up to 7 km., Hilly terrain and hills - in different ways, reception from 20 to 50 km (record) above and up to 3 km below, transmission is also from 700 m to 7 km. There is no more transmission range and no need! And the reception is also quite sufficient to slow down in front of an accident, traffic police, camera, etc. It is better to choose manual noise reduction, on the border of interference, since the automatic one greatly coarsens the reception. Easy to operate and reliable. The second flight across the country with her. Only a positive impression. Maybe there is better, but it's enough for me. Advice: fasten the antenna on the magnet in addition to the rails with clamps so that it does not move at all, otherwise the magnet (even through an elastic band) rubs the paint. I wanted to increase the power of the PRD - I disassembled and determined that the assembly was Chinese. Doesn't scare - works fine.

Rating: 5 out of 5

Advantages:

Price, quality, great welcome

Disadvantages:

it is desirable to modify

A comment:

I got myself the MJ-300 Megadgetka about six months ago.
Attracted by the following things:
1. Ease of management
2. Cost in stores and availability
3. Convenient PTT.
4. Inexpensive upgradeability

I have long wanted to install an SVshka in my car in order to be aware of traffic jams, traffic situations, repairs, etc., and just kill time on a civil wave. I read it, I thought - I bought 300ku. The price is quite reasonable.

Alanovskaya bought an antenna for it on a magnet.
I connected it to the cigarette lighter without any problems: so, it seemed to me more convenient.
I screwed the antenna to the radio, pulled the cable into the trunk, put it on the magnet.
Then I screwed on the tangent, stuck it in the cigarette lighter and Hurray! The radio works.
I went directly to the long-range channel to test the radio and indulge in the noise reduction.
Accordingly: the less the noise is strangled, the farther it takes, but the more interference on the air.
In numbers:
1. Reception: with a completely switched off noise mode up to 10 km (provided, of course, that the transmitter has a good antenna). On average 4-6 in urban conditions. When turned on for full reception, about 800-1400 m, but without a single hindrance.
2. Transmission: from Alanovskaya 145 antenna sharashit for 2-3 km in the city without problems.

This station is designed to solve completely different problems. Apparently, in this way, RKK decided to divide the market and make even more money.

And I dare say they did it. The station is quite interesting, it is not intended to work in AM, although it can work in this modulation. Her path is frequency modulation, or FM.
So, if you are a Bishnik taxi driver, or just use the band, mainly in FM, and do not want to spend a lot of money on a walkie-talkie, this station is for you. In the harsh operating conditions of taxi companies, and it is there that the MegaJet MJ-300 is most often used, the station showed itself from the best side. It is extremely simple and reliable. Now, let's take a closer look at it.

The station is delivered in a glossy silver cardboard box. Like the MegaJet, the cardboard is thin but durable.

The station is packed well. Inside the box is a shock-absorbing plastic insert designed to divide the space for transportation.

The set includes the radio station itself, instructions for English language, headset, bracket for fastening and fasteners.

Appearance
The station is very similar in appearance to MegaJet, the general pedigree can be traced well. The dimensions of the case remained the same.


The front panel is made of plastic. In appearance, plastic looks cheaper than that. It is more slippery and glossy.


The case consists of a chassis to which all the internal electronics are attached, two metal covers, an upper and a lower one. Each cover is attached separately with 4 self-tapping screws. As I already wrote in, this is not very good, because, at high volume, such a design will rattle.


The ergonomics have changed. Now it is more convenient to use the station. The knobs for volume control and squelch control are still nearby, but they are now located vertically, which, in my opinion, is more convenient. The handles rotate with little effort, but gently and without jamming. On the front panel there are buttons for switching channels, a button for changing modulation, a button for enabling channel scanning, this mode has been added here. The CH9 button has many functions, which are described below.
The display, like the one, has a pleasant amber backlight. The indication completely repeats the indication of the younger brother. The channel number, grid letter, modulation and mode 0/5 are displayed here.


The display has the same disadvantages. It is clearly visible only from the front and from above. From below, nothing is visible at all.


The headset connector is modern 4-pin, looks reliable.


The headset itself is very simple, like the one, it has only a microphone and a PTT.


The headset wire is also very soft and should not grow stiff in the cold.

The back of the station has a connector for an antenna, a jack for an external speaker and a power cord.


There is no connector for quick disconnection on the wire.

The speaker is located on the bottom cover, like almost all civilian radio stations. There is also a serial number plate.

Functions
In general, the station repeats the functions of its younger brother, but there are some peculiarities. The station has 40 channels in normal mode, and 120 channels in extended mode. AM / FM modulation, work in zeros and fives (0/5), in addition, there is a channel scan function, which can be useful in unfamiliar areas, the function is displayed on a separate SC button. The main distinguishing feature is the presence of an automatic noise suppressor with manual adjustment. If sellers in the market will tell you that the station has a threshold squelch, do not believe it! A real specter, but with the ability to adjust, which is a plus.

To put a station in multigrid mode, you need to turn off the station, hold down the A / F button and turn on the station. After a couple of seconds, you need to release the button and the EP will appear on the display, which means that we have switched to multigrid mode. The grids are switched with the CH9 button. The correspondence of the grids is as follows M - C, H - D, L - B. Total 120 channels. The station has a built-in attenuator that can be turned on by holding down the CH9 button. The letters Lo (local on) will appear on the screen, which means the attenuator is on. To turn it off, we do the same thing and LF (local off) should appear on the screen. This function can be useful in noisy broadcasting. To switch between fives and zeros, you need to turn off the station, hold down the A / F and CH9 keys and turn on the radio. The buttons must be released after a couple of seconds. The display will show the number 5 indicating that the station has switched to zeros. The scan function is turned on with the SC button. Scanning will continue until the squelch opens.

Inside
The station is made on a printed circuit board made of green textolite. The installation is neat, no soldering flaws were noticed. Not washed flux either.


And the one in the photographs was left by your humble servant during the revision. I am using no-clean flux gel. The components on the board are not signed, which may make it difficult to find the desired item.


Some of the parts are not sealed, which suggests that this printed circuit board used for the production of other radio stations. The output stage is made according to the classical scheme, based on 2SC2314 and 2SC2078.


The overall impression of the filling is positive.

Declared characteristics

Frequency range: 26.965 ... 27.855 MHz
Number of channels: 120 AM / FM
Transmitter power: 10W
Power: 13.8V
Dimensions: 138 (w) x 40 (h) x 125 (d)
Weight: 600 gr

Modifications
About the modifications to the MJ-300.

Outcome
The MJ-300, as well, is not suitable for all tasks. They divide the market harmoniously and should be used in the niches intended for them. Due to the fact that only one automatic noise suppressor is implemented in the station, its use in the truckers' channel (15AM) is not advisable, since it will simply annoy you with its constant off-case alarms. If you will be offered it for Channel 15, do not take it! For these purposes, a threshold squelch is most suitable, as, for example, in the MJ-100. The path of the MJ-300 is either working in a taxi, or using for other tasks where frequency modulation is applied.