Antenna for the radio megadget 300. Description of the connectors on the rear panel of the radio station

Compact and inexpensive Car radios cb range. This is the simplest one 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 SAMSUNG 3P9228AZZ-QZR8 digital control microprocessor. 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 of a 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 spectral squelch.

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

Manual for MEGAJET MJ-300 (in Russian).

FEATURES 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 AM / FM modes
• Button control of channels Up / Dn
• Display of channels, grid, scanning
• External speaker jack 3.5mm

MEGAJET MJ-300 SPECIFICATIONS
frequency range	26.965 - 27.405 MHz (AM) 26.965 - 27.855 MHz (FM)
Number of channels	120 (3 grids - B, C, E)
Supply voltage	13.6V
Dimensions (WxDxH)	138x125x40 mm
The weight	600 g
TRANSMITTER
output power	4 watts 18W (Turbo)
Modulation type	AM (level> 90%) FM (deviation 1.5 kHz)
Frequency stability	0.0005% (5 ppm)
Consumption in transmission mode	up to 0.9 A
RECEIVER
Type of	Superheterodyne with two IF (first - 10.695 MHz, second - 455 kHz)
Sensitivity	0.3 μV (FM, S / N 12 dB) 0.5 μV (AM, S / N 10 dB)
Signal to noise ratio	> 45 dB
Squelch threshold	0.5 μV
LF output power

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

Complete set: MEGAJET MJ-300 radio station, PTT with microphone, power cable, mounting 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.
Zone confident reception with a wire at the antenna input (ordinary wire) 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. (If, 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) at the top 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 a 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 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 walkie-talkie and indulge in the noise control.
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.

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

MegaJet MJ-300 Turbo car radio station differs from previous model MJ-300 with 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 shows 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, a small indicator, 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 station in a limited space of any dashboard car. 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"
• Opportunity to work in Russian frequency grid(offset -5 kHz)
• Built-in input attenuator
• Channel indication
• RX / TX signal level indicator
• Adjustable spectral squelch
• Scan mode
• Emergency tuning to channel 9

Overview Megajet radio stations 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 backlighting. Especially convenient when using the LCD display are the 10 mm channel numbers, 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 weekend trips out of town. Compact dimensions, low power consumption and ease of use in combination with the magnetic antenna * makes this model good choice for all. Walkie Talkie Megajet 300 Turbo 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 Russia: Kazan,Novosibirsk , Nizhny Novgorod , Omsk , Rostov-on-Don , Volgograd , Krasnoyarsk , Saratov , Voronezh , Krasnodar , Izhevsk , Ulyanovsk , Barnaul , Irkutsk , Novokuznetsk , Orenburg , Kemerovo and other cities.

MegaJet MJ-300 Turbo, megajet mj-300 turbo, MEGAJET MJ-300 TURBO, MJ-300 T, mj-300 t, Megajet 300 Turbo, megajet 300 turbo, MEGAJET 300TURBO, MJ300 Turbo, mj300 turbo, Megajet300 T, megajet300t, Megboet, MZh-300 megadget MZH-300 turbo, MEGADZHET MZH-300TURBO, MZH-300T, MZH-300t, MZH300T, MZH300t, Megadget300T, megadget300t, MEGADZHET300T, Megadget 300 Turbo, megadget 300turbo, MEGADZHET 300 TURBO, 300t.

Specifications

Transmitter power (AM / FM)	12/20 Watt
Guarantee	6 months
Operating temperature range	-20 "C + 55" C
Consumption current, maximum	2 A
Shumodav type	Spectral
Antenna connector	SO 239
Power cable length	1.1 m
FREQUENCIES
Working range	CB 27 MHz
Number of channels	120
Modulation	frequency (FM) and amplitude (AM)
Number of subcodes (analog)	No
Selecting a communication channel	manual
OPERATING MODE
Push-to-talk PTT	Yes
Voice activation	No
Busy Channel Scan	Yes
FUNCTIONS
Tone call	No
Automatic squelch	Yes
Adjusting noise canceling	Yes
Keypad lock	No
Disabling noise canceling	Yes
Sound. keystroke signal	No
Volume control	Yes
DISPLAY
Display	Yes
Display type	LCD
Display backlight	Yes
INDICATION
Operating mode indication	Yes
Power on indication	Yes
Ind. selected channel	Yes
Ind. broadcast signal	Yes
Ind. signal reception	Yes
POWER SUPPLY
Mains powered	12V (13.8V)
Antenna type	External
INTERFACES
Headset jack	standard 4 pin
Programming	No
RECEIVER
Sensitivity	0.3 μV s / n 12 dB FM / 0.5 μV s / n 10 dB AM.
Adjustable noise reduction with max. threshold	1 mV
Frequency Response Range	300 - 3000 Hz +/- 3dB
Built-in loudspeaker	6 ohm
Intermediate frequency 1 IF:	10.695 MHz, II IF: 455 kHz
Nonlinear distortion	at a frequency of 1 kHz 5%
TRANSMITTER
Output power in AM mode	Up to 12 W
FM output power	Up to 20 W
Suppression of spurious radiation	within normal limits
Output Impedance	50 ohm
EQUIPMENT
Radios included	1
Antenna	not included
COLOR / SIZE / WEIGHT
Colour	black
Overall dimensions (H * W * D)	40x125x138 mm
The weight	690 BC
Country Manufacturer	Korea MegaJet

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 has shown itself to be the best. It is extremely simple and reliable. Now, let's take a closer look at it.

The station is supplied 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, on high volume this 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 radio stations civilian range... 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, do the same 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 activated 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 harmoniously divide the market 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 used.