COFDM video transmitter-receiver FAQ

COFDM video transmitter receiver AV in HDMI out FPV, Wireless 10km-15km-30km long-range cheaper and longer

AES 128 Video Encryption

Strong video encryption function to ensure the video security.

Longer Distance

2 Watts Power Amplifier, support 30KM transmission distance

Frequency Modifiable

Transmission frequency is modifiable by the parameter configuration board.

Signal Strength

Receiver screen can shows the signal strength of the transmitter, users can move better reception place.

Video + Data

Except video, it also support download data via the UART from the transmitter to the receiver. One-Way, Simplex.

Lower Latency

The lower latency delay is less than 200~300 millisecond.

LOS and NLOS

Support LOS (Line-Of-Sight) 30km and NLOS (Non-Line-Of-Sight) 1.5km Test Video

Full set in the package

The package is including transmitter, receiver, both side antenna and accessories cable.

Selling Points

Support Encryption

Powerful PA RF output (1 Watts or 2 Watts)

720P composite CVBS AV in on the transmitter, AV + HDMI output on the receiver

Support NLOS LOS long-range transmission

Optional parameter configures board for current parameter showing and adjustable

Recommended to use the fiberglass antenna to support strong signal and long-range

H.264/MPEG-2 encoder

Delay latency <300 Millisecond;

What is the COFDM Video Transmitter?

1. COFDM-912T adopts advanced COFDM (multi-carrier modulation technology), which integrates transmitting antenna, digital modulation, and audio and video digital compression.
2. COFDM wireless video transmitter has a small size and a long transmission distance. Modular combined design can be used with secret shooting clothes and small cameras and can realize hidden on-site high-definition image collection and transmission.
3. COFDM wireless video transmitter is a highly integrated mobile non-line-of-sight digital mobile video wireless image transmission equipment that can transmit real-time and stable audio and video in high-speed movement and under the condition of urban buildings.
4. The COFDM Wireless Video transmitter-receiver transmission system can reach a transmission distance of more than 500 meters and a line of sight of more than 10 kilometers under general blocking conditions.
5. COFDM Wireless video transmitters using high-gain directional antennas or omnidirectional antennas can further increase the transmission distance.
6. If you need a longer transmission distance, you can use the existing wired network, mobile communication (satellite), and use our company’s portable relay transmission equipment or vehicle-mounted wireless video transmission system for relay transmission. The transmission distance of the system can reach more than 20 kilometers.
7. There are 3 different powers for the secret shot type equipment (0.5W, 1W and 2W@average power PA). The greater the power, the stronger the signal penetration and the longer the transmission distance.
8. Transmission distance: visual environment ≥ 10km. Blocking environment: ≥500m (different depending on the environment)

(if you need long-range, we also have 5W, 10W, 20W PA products, see here)

Feature

1. Highly integrated, modular design
2. Adopt COFDM modulation technology, MPEG-2 image compression technology
3. All-round communication, not afraid of building walls
4. High-speed inter-line communication, real-time, stable DVD image quality for audio/video transmission
5. Heat sink aluminum housing, shockproof and shock-resistant
6. High-fidelity digital stereo transmission
7. Non-line-of-sight (NLOS) mobile transmission for longer distance

Applications

This product is mainly used for technical reconnaissance and forensics in the military and security inspection departments. Radio and television broadcast, radio and television live broadcast: broadcasting field, sports broadcast, social news, aerial live, studio, mountain adventure, and so on. It is suitable for real-time mobile transmission of high-quality images in many complex environments such as urban, marine, and mountainous.

For drones ( recommend adding extra wave filters, need extra cost )
For CCTV

Specification

Receiver:

1. Can I change the transmitter and receiver frequency?

Yes, the frequency can be changed from 170Mhz to 860Mhz.
The frequency should be modified to the same on the transmitter and receiver. Of cause, the Power Amplifier and antenna frequency should modify the same frequency. (You need to buy a power amplifier and antenna for the transmitter and receiver to meet your changed frequency).

The default frequency is 590Mhz, With 30Mhz (+/-15Mhz), you can change it without modifying the Power Amplifier and antenna. For example, 578Mhz, 584Mhz, 590Mhz, 596Mhz, and 602Mhz.

2. Does this transmitter can send video and data (uart) to the receiver?

Yes, it supports to send the video and UART data from the transmitter and receiver.
As it is one-way transmission, so it can not send the control command from the receiver to the transmitter.

If you need to send control commands or other data from the receiver to control other devices such as cameras or drones at the transmitter, you can add a set of cheap digital transmission equipment, contact us, and we can customize it for you.

Please check the UART define on the transmitter and receiver at the below link. Please tell me if you want to have a lead cable. (default is no)

3. What the maximum distance does it support? Can I use 5W or 10W PA (power amplifier)?

The transmitter default Power Amplifier is 2 Watts, so it can support 30 KM at line-of-sight.

The below picture is our tested distance from the mountain to the seaside.

If you want to transmit a longer range, you can increase the power amplifier. In addition to one watt and two watts, we can also make 5 watts, 10 watts, and 20 watts for your choice. Larger amplifiers also require larger batteries and current support.

4. Will the COFDM-912T perform as well at 300MHz as it does at 600MHz?

Our engineer can change frequency to 300Mhz from default 590Mhz, The antenna and PA in the warehouse are 590Mhz, 300Mhz need two weeks for customize, so the delivery time needs longer than our default 590Mhz.

5. It is cheapest and longest video transmission, but it has CVBS input only, how to connect my HDMI camera?

Yes, it support 720P CVBS video input on the transmitter and 1080P HDMI video ouput on the receiver.

If your camera is HDMI connector, you can use one HDMI to CVBS video convertor box, it will be much cheaper than you used one wireless video transmitter.

If you still need HDMI input on the transmitter, then the below model is recommended.

6. I have changed the parameter on the configure board tool, why it is not saving when I restart?

Step 1: Please press OK and the right button at the same time, a menu of whether to save appears on the screen.

Step 2: Please press OK to choose Yes to save.

7. Can I change the frequency to 300 Mhz when I received your cargo?

Yes, you can change the frequency to 300Mhz, but this is not recommended.

Why?

1. Our wireless video transmitter and receiver both support AES128 encryption and decryption. The password can be changed on the configuration board at any time. It is safe for your video.

2. If you change the frequency on the transmitter and receiver to 300Mhz, the antenna and Power Amplifier frequency should be changed to 300Mhz also.

For a small number of special frequency antennas, maybe the antenna factory will not agree to special produce.

3. Maybe the antenna problem is solved. The power amplifier in the transmitter is preset, and we also send you the test video before the delivery. If the end-user modifies the power amplifier frequency, it is easy to be burned. Without a power amplifier, then this system can not be working well the long distance. The buyer has to send it back to the China factory for repair, Although our repair is free, but the buyer has to pay all the shipping costs.

4. Please tell us what frequency the buyer wants to have, we will modify and test its quality in the factory. after QC passed, we will send you.

8. I see that the 912T device has a UART pin. Is it for config or communication?

COFDM-912T is a one-way wireless transmission system.

That means it only downloads the video or data from the transmitter to the receiver, but it can not upload the UART data from the receiver to the transmitter, for example, it can not control the transmitter's camera or drone.

Is it suitable for your project?

Or check the below link, we will understand clearly your project.

https://ivcan.com/request-a-quote-of-wireless-video-transmission/

9. How smallest the wireless video transmitter antenna can you offer?

Now we can offer you the smallest transmitter antenna is 13 cm in length.
Remind, please use the bigger or longer antenna if your project allows, it can get better reception performance in the larger range.

10. What is the default of the full set COFDM-912T you recommended? How about the package for the shipment?

The default full set

1. SD Transmitter ( PA 0.5W, 1W, 2W, 5W optional according to your order demand)
2. SD Transmitter antenna
3. HDMI CVBS output receiver with parameter control menu and small screen
4. 0.8-meter Receiver antenna 1 pcs. (There are two types of installing or fixing the antenna: 1. magnetic base metal antenna, 2. U-type fiberglass antenna )
5. Optional, parameter configuration board for the wireless video transmitter.

The default full set package dimension

1. 126*30*12CM
2. Gross Weight 7.5KG
3. Some freight forwarders will charge extra fees, such as extra long fees and extra fees for strong magnetic items

11. Can I use the parameter configure board on the receiver to work on the transmitter, I want to adjust the signal attenuation on the transmitter.

The transmitter parameter configures board can adjust the signal attenuation on the transmitter.

The transmitter parameter configures board is different from the one on the receiver.

The firmware on the parameter configure board was different from the transmitter and receiver, they cannot be used interchangeably.

Gallery

Warning

1. As this transmitter has built-in 1W or 2W PA inside, please connect the transmitter antenna first then give it the power to protect the transmitter PA Power Amplifier.
2. In order to ensure the stability of the sending and receiving signals of the image transmission and the smooth transmission of the picture, please do not block the antenna as much as possible, and try to place it in a high place, such as on the roof or on a tripod.
3. Please keep the antenna vertical.
4. Please make sure that there is a certain height difference between the transmitting antenna and the receiving antenna.

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