COFDM bežični video odašiljač i prijemnik
Sadržaj
COFDM Wireless video transmitter and receiver Dimension
2-watt PA COFDM Wireless Video Transmitter
Veličina: 90x65x22 mm
The most recent advancements in COFDM (Kodirano ortogonalno frekvencijsko multipleksiranje) wireless video transmitter and receiver technology have transformed how video is transmitted and received. COFDM is a modulation technique that allows digital data to be transmitted over a wide range of frequencies, resulting in a more reliable signal and improved data transmission.
We use COFDM technology in numerous applications, such as digital television, bežični video prijenos, i digitalni radio. It’s also found in military and aerospace applications like satellite communications and unmanned aerial vehicles.
Konačno, recent advancements in COFDM wireless video transmitter and receiver technology have transformed the way video is transmitted and received. This technology has enabled high-definition video transmission over wireless networks, as well as video transmission over a variety of networks and devices. The use of advanced coding techniques, such as forward error correction (FEC) and adaptive modulation, has enabled this.
5-watt PA COFDM Wireless Video Transmitter
5-Watt PA COFDM-912T Weight
Package for one full set of the COFDM Wireless Video Transmitter
FAQ of the COFDM Wireless Video Transmitter and Receiver
bok, I am looking for a long-range hd video transmitter with hdmi input and a receiver with hdmi output.
Would you like a jedan način ili dvosmjerna sistem? As long as you need to send the video, do you still need to send the control operation of the drone?
Only transmit and receive in a surveillance center. The idea is to use the HDMI output of the remote control and retransmit it to the central. The drone has a system to transmit over the internet, but there is no internet in the desert, so we need to retransmit but not with the internet.
u redu, our one-way long-range wireless video transmission solution is the base of COFDM technology (similar to DVB-T digital TV broadcasting). It is not on the base of the Internet.
Does this COFDM wireless video transmitter and receiver have AES 256 ili 128 šifriranje? the output format is full hd?
Da, COFDM-912T supports AES 128 šifriranje. Please notify us to plus a Parameter Configuration board for setting the AES128 password when you are placing the order. It is optional to buy.
The COFDM-912T transmitter only supports SD720P Video input. So even if the receiver has HDMI output, it cannot output real 1080P high-definition video, only 720P.
If you have very high requirements on the definition of picture output, I suggest you choose a model that both the transmitter and receiver support 1080P, COFDM-908T
Can it reach 30 km around?
In the introduction of the wireless video transmission system, all the transmission distances mentioned are based on the visible range (THE). The 2WPA power amplifier supports 30 kilometers and is usually used on drones. The altitude is very high and the receiver is on the ground, so there is an obvious height difference between the transmitter and the receiver, and the wireless signal is transmitted in accordance with the waveform. The signal loss is small and other interference is very little clutter.
You mentioned that your usage scenario is that both the transmitter and receiver are on the ground, especially in desert areas, and there may be rolling sand dunes. Stoga, the signal transmitted wirelessly is easily interfered with. So here are the suggestions:
1. Try to use a high-power transmitter, kao što su 10 Watts ili 20 Watts. Many of our ship customers use 20W transmitters.
2. Try to use a higher antenna or put the antenna on the roof or a nearby hill, and you can also increase the antenna tripod. Our clients always choose some 1.8-meter FRP omnidirectional fiberglass antennaa.
3. If conditions permit, a repetitor can also be added to enhance the signal strength and increase the transmission distance. The repeater can be fixed at a high place or on the roof of a moving car.
How to assemble the wireless video transmitter, fotoaparat, and battery?
Molimo provjerite donju sliku. 
There are two power connectors at the transmitter, the red connector is 12V output for the camera, and the black connector is 12V input.
What is the lag or delay in milliseconds of your COFDM-912T?
200-300ms with a regular camera and monitor.
Normal camera and screen have a delay of 200 milisekundi, pravo?
With our 100 milisekundi, it’s about 300 do 400.
We also have one with 30 milisekundi, but the price is 6 times that
300 milliseconds is acceptable if your plane has an automatic obstacle avoidance function.
I noted your transmitter can support up to 30 kilometers in LOS. How far will it support in the NLOS environment?
It’s hard to say the range of non-line-of-sight use, it depends on how many obstacles are in the middle. It is difficult to transmit if fully surrounded metal or mountains block it.
The test environment is unique, and the distance obtained from the test is also different. We can’t make any guarantees or promises about this.
We are a company that offers a solution to some rural areas here in the Philippines to monitor their rivers. If we purchased a 2W(30km) in the NLOS location, it could be reduced to 20km or more?
It is hard to say, it should depend on the obstacles between the transmitter and receiver. We don’t test it in your use environment, So I can’t tell you.
The same product will be interfered with differently in different environments, and the transmission distance is hard to say. Only the actual test will know.
Buyer: Actually, we have installed a radio transceiver that gathers a data sensor and transmits its data to an 18km distance center command. The operation is smooth and ok.
The same place we’re going to put up the device that we will buy from you.
As you have said, only an actual test will answer all of my questions.
Can the COFDM-912T TX device output separate serial data?
Data can only be transmitted in one direction from the transmitter to the receiver.
If you need to transmit data in both directions, you need to add a digital radio telemetry. (wireless data transceiver).
I would like to know if the transmitter can also output serial data on what the camera is capturing. Other than RF does it have a separate rs232 output for the transmitter?
Da, COFDM-912T supports transferring the serial data for you. Molimo provjerite donju sliku. 
In this module where I can put up the camera? What type of camera is suited for this device?
The black one on the left shows a little bit of the above picture, which is connected to the camera.
It supports a 720p CVBS composite AV camera. or any HDMI camera by HDMI to AV converter box.
How can I let the transmission still work well if I remove the menu and panel board from the receiver?
Is there any way to disable the control panel so that the receiver can see the video from the transmitter?
If I remove the control panel on the receiver, the receiver does not see the signal from the transmitter.
Odgovor: Please check the FAQ in the below link.
https://ivcan.com/p/cofdm-video-transmitter-receiver-av-in-hdmi-out/#accordion-item-6._i_have_changed_the_parameter_on_the_configure_board_tool,_why_it_is_not_saving_when_i_restart?
I guess that you did not save the frequency, after you remove the menu on the receiver, the system will be back to the default frequency of 340Mhz. So you can not get the signal.
If GPS and TX are separated less than 1 metar – GPS is jammed. COFDM-912T has significant noise in GPS l1 and l2 freq. Do you have any low-pass filters to solve this problem?
bok! We did extensive testing before ordering a bigger batch. And faced issues if combining the COFDM-912T transmitter with GPS.
Odgovor:
1. If you buy it again, I can add a low pass filter in the transmitter inside free. I can also provide an external low-pass filter for you for free.
2. “Do you know what insertion loss is in non-filtered frequency?”, Odgovor: max 0.6db
3. “Do you know what dBm loss is pass frequency?” 0.4dBm
COFDM-912T Customize Development
2 Watts default 595Mhz with 1.8-meter transmitter and receiver antenna
The client told us that his application details, the transmitter and receiver, are both used on the ground. In order to enhance the wireless transmission distance and avoid other signal interference, I recommend that both the transmitter and receiver antennas use 1.8-meter fiberglass antennas.
It was the first time the customer took the sample for testing, so he used the default two-watt amplifier and 595 MHz frequency.
The customer requires that the transmitter have an HDMI output so that he can transmit the received video to other devices. U isto vrijeme, in order to support HDMI input, I also matched an HDMI to CVBS RCA AV converter box.
The customer has added an optional parameter adjustment tool, the main function of which is to modify the transmitter’s transmission frequency and impedance. You can also add a password to the wirelessly transmitted video to encrypt the video of the transmitter. We must enter the same password on the receiver to decode the video to improve the security of the video.
Change COFDM Transmitter to 200 mW PA, with a power switch of the cooling fan for body wear
Customize a video on-off switch on the COFDM Transmitter for audio-only wireless transfer.
Here is the test video for this client’s requirement, added a video on-off switch at the 10-watt PA wireless video transmitter to transfer the audio only.
Here is a video to show you that we can add one video on-off switch on the COFDM wireless video audio transmitter.
Video on, then the transmitter will transfer the video and audio at the same time.
Video off, then the transmitter will transfer the audio only.
If you have any project or need to customize the function of the wireless video transmitter and receiver, molimo kontaktirajte nas.
The default power amplifier is 2-watt, we also make a 10-watt PA inside, to support long-range and transfer more extended distances.
2 Watts default 595Mhz with Yagi Directional Antenna and Omnidirectional antenna
300 Watts power amplifier modified 230Mhz COFDM wireless video transmitter and receiver
FAQ
- Da, frekvencijski raspon se može mijenjati od 170Mhz (bolje od 220Mhz) na 860MHz. Tako da može dobro raditi na frekvenciji od 260 Mhz.
- Frekvenciju treba promijeniti na istu na odašiljaču i prijemniku. S razlogom, frekvencija pojačala snage i antene treba mijenjati istu frekvenciju. (Morate kupiti pojačalo snage i antenu za odašiljač i prijemnik kako biste zadovoljili svoju promijenjenu frekvenciju).
- Kako bi se poboljšala osjetljivost odašiljanja i primanja, širina frekvencijskog pojasa općenito je vrlo uska (središnja frekvencija ±15MHz, tako da bi širina pojasa trebala biti 30MHz). Pojačalo snage odašiljača i frekvencija antene posebno su prilagođeni prema frekvenciji koja vam je potrebna.
- Najbolje je kada naručite, molim vas recite mi kakvu radnu frekvenciju trebate. Naši inženjeri će modificirati frekvenciju odašiljača i prijemnika, i također modificirajte PA i prilagođenu antenu prema ovom frekvencijskom rasponu kako bi se osigurala najbolja osjetljivost i podržala najveća udaljenost prijenosa.
- Zadana frekvencija je 590MHz, Sa 30Mhz (+/-15MHz), možete ga promijeniti bez modificiranja pojačala snage i antene. Na primjer, 578MHz, 584MHz, 590MHz, 596MHz, i 602MHz.
- Ako trebate promijeniti frekvenciju i propusnost odašiljača, potreban vam je poseban alat ploče za konfiguriranje parametara, pogledajte sliku ispod, nije zadana dodatna oprema, kupite ga uz dodatnu cijenu ili nas kontaktirajte prije naručivanja.
Da, podržava slanje video i UART podataka od odašiljača i prijemnika.
Budući da je to jednosmjerni prijenos, tako da ne može poslati upravljačku naredbu od prijamnika do odašiljača.
Ako trebate poslati upravljačke naredbe ili druge podatke s prijemnika za upravljanje drugim uređajima poput kamera ili dronova na odašiljaču, možete dodati skup jeftine opreme za digitalni prijenos, Kontaktirajte nas, i možemo ga prilagoditi vama.
Molimo provjerite UART definiciju na odašiljaču i prijemniku na donjoj poveznici. Recite mi, molim vas, želite li imati vodeći kabel. (zadano je ne)
Zadano pojačalo snage odašiljača je 2 Watts, tako da može podržati 30 KM na liniji vidljivosti.
Donja slika je naša testirana udaljenost od planine do mora.
Ako želite odašiljati veći domet, možete povećati snagu pojačala. Osim jednog vata i dva vata, također možemo napraviti 5 vata, 10 vata, i 20 vata po vašem izboru. Veća pojačala također zahtijevaju veće baterije i strujnu podršku.
Za 20W PA, napajanje bi trebalo biti 24~28V. Samo kod 28 volta može li pojačalo snage postići najbolju radnu sposobnost.
Naš inženjer može promijeniti frekvenciju na 300 Mhz sa zadanih 590 Mhz, Antena, i PA u skladištu su 590Mhz, 300Mhz treba dva tjedna za prilagodbu, tako da vrijeme isporuke treba dulje od naših zadanih 590Mhz.
Korak 1: Pritisnite istovremeno OK i desnu tipku, na zaslonu se pojavljuje izbornik želite li spremiti.
Korak 2: Pritisnite U redu za odabir Da za spremanje.
Podsjetiti, koristite veću ili dužu antenu ako to vaš projekt dopušta, može postići bolje performanse prijema u većem rasponu.
Zadani puni skup
- SD odašiljač ( PA 0,5W, 1W, 2W, 5W, 10W, 20W, 50W izborno prema zahtjevu vaše narudžbe)
- Antena SD odašiljača
- HDMI CVBS izlazni prijemnik s izbornikom za kontrolu parametara i malim zaslonom
- 0.8-metar Prijemna antena 1 kom. (Postoje dvije vrste postavljanja ili fiksiranja antene: 1. magnetic sucker base antena, 2. Zadano U-tip stezaljke FRP antena od stakloplastike )
- neobavezan, ploča za konfiguraciju parametara za bežični video odašiljač.
(Ako vam je potrebna magnetska bazna antena, ekspres ili prijevoznik misli da će magnetski proizvodi ometati njihovu sigurnost u zrakoplovu, tako da je trošak dostave veći od U-tipa stezne antene. )
Zadana dimenzija kompletnog paketa
- 84*21*12CM
- Bruto težina 4,5 kg
- Ako odaberete više od 100 cm antene i antene s magnetskom bazom, Neki će špediteri naplatiti dodatne naknade, kao što su ekstra duge naknade i dodatne naknade za jake magnetske predmete.
- Parametar odašiljača koji konfigurira ploču razlikuje se od onog na prijemniku. Firmware na ploči za konfiguriranje parametara razlikovao se od odašiljača i prijamnika, ne mogu se koristiti naizmjenično.
- Parametar odašiljača konfigurira ploču koja može prilagoditi prigušenje signala na odašiljaču. Za 0,3 db će se smanjiti 0,5 W PA.
Pitanje: Je li moguće promijeniti izlaznu snagu (unutarnji PA 0,5 w, 1 w, 2 w) putem konfiguracijske ploče?
- Kao što je gore odgovoreno, možete podesiti izlaznu snagu postavljanjem parametara ATTEN putem alata ploče za konfiguraciju parametara na odašiljaču. (Ovaj alat ne uključuje zadani paket, trebate obavijestiti da želite imati ovaj alat kada naručite)
- Ako kupite 2W PA, tada možete postaviti 0,5 W, 1W, ali ne mogu ga promijeniti na 5W.
- Također možemo napraviti do 5W, 10W, 20W, i 50 W ako trebate podržati dugo domet.
Ne.
Ovaj bežični video odašiljač podržava samo CVBS kameru ili video ulaz, druga vrsta video kamere treba dodatnu kutiju pretvarača.
Ne. To je COFDM (DVB-T) tehnologija.
Dakle COFDM frekvencijski raspon je 170-860Mhz. Može podržati 477, 610, 675, 724, 816MHz, ali ne može podržati 970, 1180, 1230 MHz.
Naš poseban model odašiljača može podržati sve gore navedene raspone, ali prijamnik treba koristiti blok pretvarača prema dolje.
Kako bismo omogućili našem sustavu bežičnog prijenosa da podržava širi raspon i bolju snagu signala, radnu frekvenciju općenito postavljamo na određenu točku (170~860MHz), a njegov podržani raspon je samo plus ili minus 15Mhz. Na primjer, središnja frekvencija je 590Mhz, maksimalni frekvencijski raspon podrške trebao bi biti 575Mhz~605Mhz, PA i antena su posebno prilagođeni prema ovoj središnjoj frekvenciji.
How to add a low-pass filter chip to the transmitter?
Some customers reported that when the distance between our transmitter and the GPS antenna is less than one meter, the transmitter will interfere with the work of the GPS through the transmitting antenna.
GPS satellite signals are divided into L1 and L2, with frequencies of 1575.42MHZ and 1228MHZ respectively. Our transmitter frequency is 595Mhz by default. If we encounter this situation, we can consider adding a low-pass filter, which means frequencies below 600Mhz. Frequencies above 600 MHz can be suppressed to avoid interference with other emitting electronic products.
There are two ways to add a filter. One is to add a filter IC to the COFDM-912T transmitter board, and the other is to add a filter box outside the transmitter. The down-pass filter can suppress frequencies below a certain frequency point, and the wave-pass filter can suppress the frequencies below a certain frequency point by allowing them to pass through.
