User manual for wireless video transmitter HD

Disclaimer

• Please read the user’s manual carefully before use. Be sure to pay attention to the warnings and understand all points completely.
• Please strictly abide by the local radio frequency management regulations.
• Please follow the installation steps in the manual to use this product. Our company and agent will not take legal responsibility for the damage of equipment or personnel caused by the installation and modification of users.
• This copyright of this manual belongs to Great Mainlink Tech Co., LTD. No one may make copies without written consent.

Caution                

Attention to installation                    

1. Before power on, make sure the antenna connection is reliably . Otherwise, it will cause damage to the device.

2. Make sure that the voltage is within the range of use.

3. Please pay attention to the EMC of all the electronic equipments on your drone.

4. It is recommended that the antenna should be installed downward and keep the antenna away from the metal on the drone.

5. Make sure to use the matching antenna.

Before use                                        

1. Make sure that all cables are connected correctly and firmly.

2. No foreign objects (e.g. liquids, sand, etc.) can be entered inside the device.

3. It takes 15 seconds for the device to start. Video and data cannot be transferred until the device has finished booting.

4. Please ensure that the environment in which the equipment is used is free of other electromagnetic interference.

5. When the signal weakens, you can improve the effect by changing the heading direction of the antenna.

Packing list

Device X 2

Overview

Industry drone market is developing very fast in recent years. The fight time and distance of drones are getting longer and longer. MK22/MK55, a long-range wireless transmission system, is designed for VTOL fixed wing and other long-range drones. The system can transmit video, fight control data, gimbal control data, and RC data simultaneously. With the advantage of high level intergration and powerful function, MK22/MK55 is a typical good product to meet long-range transmission requirements.

There are two frequency bands——800MHz、1.4GHz and 2.4GHz. Users can choose according to their needs. Please choose the suitable frequency band according to local regulations.

MK22 can transmit data and video to 22km, MK55 can transmit data and video to 55km, making it very suitable for long range drone.

If you use our recommend ground station, you only need one cable with connector to connect the device and your ground station.

^*1Test under LOS and no interference conditions。

Features

Long distance Modulation

-MK22  Up to 22km @ LOS          – OFDM

-MK55  Up to 55km @ LOS

Video interface Data interface

– Ethernet *1            – UART（TTL/RS232）/SBUS，

Hopping/Fixed Frequency Frequency Band

-Fixed: user defined   – 800MHz/1.4GHz/2.4GHz

-Hopping:  automatic   Working mode

BW – Air unit can be ：Point to point mode

-5/10/20 MHz   Repeater mode

Work temperature Power range

– 40℃～+70℃ – DC  9~28V  Battery 3S~6S

M52 Interface Description

Air unit  

side view

Ethernet

Number	Character	Description	Input/Output
1	T+	TX+	O
2	T-	TX-	O
3	R+	RX+	I
4	R-	RX-	I

2. UART1

Number	Character	Description	Input/Output
1	G	GND	I/O
2	R	RS232 RX	I
3	T	RS232 TX	O

3. UART2

Number	Character	Description	Input/Output
1	G	GND	O
2	R	TTL RX	I
3	T	TTL TX	O

4. Power

Number	Character	Description	Input/Output
1	G	GND	I/O
2	V	+Vcc（9v~28v）	I

5. SBUS1

Number	Character	Description	Input/Output
1	S	SBUS OUT	O
2	V	+5v（I max 1A）	O
3	G	GND	I/O

6. SBUS2

Number	Character	Description	Input/Output
1	S	SBUS OUT	O
2	V	+5v（I max 1A）	O
3	G	GND	I/O

7. Power indicator

This indicator is solid green when air unit is booting.

8. Link indicator

LED Pattern                       Description

solid green                     Wireless link is established

light off                         Wireless link is lost

9. Status Indicator

LED Pattern（Blink only in booting）       Description

Blink 2 times                  Initialization OK, Frequency is 1.4GBlink 1 time                   Initialization OK, Frequency is 800M

Blink 3 times                  Switch mode (Swith from air to ground, vice verse)

Blink slow all the time          Enter configuration mode

Blink fast all the time           Device abnormal

10. SMA antenna connector.

1. Fiber glass antenna.
2. OLED display.
3. Battery
4. Connector.

Number	Description	Input/Output
1	Rx+	I
2	Rx-	I
3	Tx+	O
4	Tx-	O
5	UART1 TX (RS232)	O
6	UART1 RX (RS232)	I
7	UART2 TX (RS232)	O
8	UART2 RX (RS232)	I
9	NC
10	RC1_IN	I
11	RC2_IN	I
12	+5v	O
13	GND	I/O
14	GND	I/O
15	GND	I/O
16	GND	I/O
17	GND	I/O
18	GND	I/O
19	Vcc (9v~28v)	I
20	Vcc (9v~28v)	I

Specification            

Category	Item	Detail
WirelessPerformance	Frequency band	800MHz/1.4GHz
	Frequency range	800MHz：806MHz～825MHz1.4GHz：1427MHz～1447MHz2.4GHz:  2400~2480MHz
	Band width	5MHz/10MHz/20MHz
	Modulation	OFDM
	EIRP	MK22: 30dBm±1dBMK55: 33dBm±1dB
	Sensitivity	≤-95dBm
	Range	MK22: 22kmMK55:55km*1
	Bit rate	30Mbps@20MHz
Power Range	DC 9~28V
Power consumption	≤8.5W
Interface	Antenna	SMA *2
	Power	XT30
	UART	TTL 3.3V，1 start bit, 8 data bit, 1 stop bit, no parity., Baud rate 115200（default），57600, 38400, 19200, 9600
		UART1 and UART2
	SBUS	SBUS_IN
		SBUS_OUT
	Ethernet	4 Pin
	Button	1
	Switch	For air and ground switch
Antenna	Interface	SMA
	Type	Air：Glue stick antenna  20cmGround：Fiber glass antenna, penal antenna
	Polarization type	Vertical
	Gain	Air：2.5dBiGround：12dBi
	SWR	≤2.0
Environment	Work temperature	-40℃～+70℃
	Storage temperature	-40℃～+85℃
	Humidity	5~95%，non-condensing
Appearance	Size	112 X 63.5 X 19 mm
	weight	143g

---

Overview

The drone industry has grown rapidly in recent years, with significant improvements in endurance, flight range, and payload capacity. As drones are increasingly used in fields such as aerial surveying, mapping, environmental monitoring, logistics, and security, the need for reliable long-range communication systems has become a critical requirement. The MK22 and MK55 Long-Range Wireless Transmission Systems are designed specifically to meet these demands.

Built for VTOL (Vertical Take-Off and Landing) fixed-wing aircraft, multi-rotor UAVs, and other long-range drone platforms, the MK22/MK55 systems provide robust and secure wireless transmission of real-time video, flight control data, gimbal control signals, and RC (remote control) data simultaneously. With their high integration level, stable performance, and versatile frequency band options, these systems are ideal solutions for both professional and industrial UAV applications where dependable communication is essential.

The MK22 system supports data and video transmission over 22 kilometers, while the MK55 is capable of reaching 55 kilometers under line-of-sight (LOS) and low-interference conditions. These distances make them highly suitable for applications where beyond visual line of sight (BVLOS) operations are required.

Both models support three selectable frequency bands—800 MHz, 1.4 GHz, and 2.4 GHz. Users can select the appropriate band depending on local regulatory requirements and operational needs. This flexibility ensures compliance across regions and allows optimization for different environmental conditions.

When paired with the recommended ground station, the system can be connected easily using a single cable with a dedicated connector, simplifying integration and setup.

---

Key Features

1. Long-Distance Transmission
   • MK22: Supports up to 22 km transmission range (LOS).
   • MK55: Supports up to 55 km transmission range (LOS).
   • Both systems use advanced OFDM modulation, ensuring efficient bandwidth use and robust signal stability.
2. High Data Rate & Low Latency
   • Data throughput up to 30 Mbps @ 20 MHz bandwidth.
   • Capable of transmitting HD video, telemetry, and control signals with minimal delay.
3. Multi-Interface Design
   • Ethernet for video/data transmission.
   • UART (TTL/RS232) for telemetry and control data.
   • SBUS input and output for RC control integration.
   • HDMI input/output support on air and ground units for high-definition video.
4. Flexible Frequency Selection
   • Fixed or automatic hopping modes.
   • Frequency bands: 800 MHz, 1.4 GHz, and 2.4 GHz.
   • User-defined fixed channel configuration supported.
5. Operating Modes
   • Point-to-point mode for direct link communication.
   • Repeater mode for extended coverage or relay-based communication.
6. Rugged & Reliable Performance
   • Operating temperature: -40℃ to +70℃.
   • Power input: DC 9~28V, compatible with 3S–6S LiPo batteries.
   • Power consumption: ≤8.5W, optimized for UAV onboard use.
7. Indicators & Status Feedback
   • Power indicator: Solid green during boot.
   • Link indicator: Shows wireless connection status.
   • Status indicator: Provides initialization, configuration, and error signals via LED blinking patterns.
8. Antenna System
   • Air unit: Glue-stick antenna, 20 cm, lightweight for drones.
   • Ground unit: High-gain fiberglass or panel antenna, designed for long-range reception.
   • Polarization: Vertical, with gain of 2.5 dBi (air) and 12 dBi (ground).

---

Technical Specifications

Wireless Performance

• Frequency Bands: 800 MHz / 1.4 GHz / 2.4 GHz
• Frequency Range:
  • 800 MHz: 806–825 MHz
  • 1.4 GHz: 1427–1447 MHz
  • 2.4 GHz: 2400–2480 MHz
• Bandwidth Options: 5 MHz / 10 MHz / 20 MHz
• Modulation: OFDM
• Output Power (EIRP):
  • MK22: 30 dBm ±1 dB
  • MK55: 33 dBm ±1 dB
• Sensitivity: ≤ -95 dBm
• Maximum Data Rate: 30 Mbps @ 20 MHz

Power & Interface

• Input Voltage: DC 9~28V
• Battery Support: 3S–6S LiPo
• Power Consumption: ≤8.5W
• Interfaces:
  • SMA antenna connectors × 2
  • Ethernet (4-pin)
  • UART1 (RS232) / UART2 (TTL)
  • SBUS IN / OUT
  • Power via XT30 connector
• Control Switch: Air/Ground mode switch

Antenna

• Air Unit: Lightweight glue-stick antenna, 20 cm, 2.5 dBi gain
• Ground Unit: Fiberglass or panel antenna, 12 dBi gain
• SWR: ≤ 2.0

Environmental

• Operating Temperature: -40℃ ~ +70℃
• Storage Temperature: -40℃ ~ +85℃
• Humidity: 5% ~ 95%, non-condensing

Physical

• Dimensions: 112 × 63.5 × 19 mm
• Weight: 143 g

Note: Range tests were conducted under line-of-sight (LOS) and no-interference conditions.

---

Applications

The MK22/MK55 long-range transmission systems are designed for a wide range of industrial and professional UAV applications where reliability, distance, and stability are critical. Typical use cases include:

• Aerial Surveying & Mapping: High-resolution video and telemetry data transfer over extended distances.
• Agricultural Monitoring: Real-time crop health analysis and environmental monitoring in wide fields.
• Security & Surveillance: Law enforcement, border patrol, and infrastructure monitoring.
• Search & Rescue (SAR): Long-range communication support in disaster zones.
• Logistics & Delivery Drones: Stable transmission of control and monitoring signals for BVLOS operations.
• Military & Reconnaissance: Secure and reliable wireless data/video transmission for tactical UAVs.

---

Optional Configurations

• Frequency Band Options: Select between 800 MHz, 1.4 GHz, or 2.4 GHz based on local regulations.
• Antenna Options: Ground station antennas available in panel, fiberglass, or high-gain directional configurations for maximum range.
• Video Output Options: HDMI output for HD display or Ethernet-based data streaming.
• System Integration: Customization available for different UAV platforms and control systems.