Table of Contents
COFDM Wireless video transmitter and receiver Dimension
2-watt PA COFDM Wireless Video Transmitter
サイズ: 90×65×22mm
The most recent advancements in COFDM (コード化された直交周波数分割多重化) 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, ワイヤレスビデオ伝送, and digital radio. It’s also found in military and aerospace applications like satellite communications and unmanned aerial vehicles.
ついに, 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
Hi, I am looking for a long-range hd video transmitter with hdmi input and a receiver with hdmi output.
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.
わかりました, 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 または 128 暗号化? the output format is full hd?
Yes, COFDM-912T supports AES 128 暗号化. Please notify us to plus a パラメータ設定ボード 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 (ロス). 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. したがって, the signal transmitted wirelessly is easily interfered with. So here are the suggestions:
1. Try to use a high-power transmitter, のような 10 ワットまたは 20 ワット. 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 antennas.
3. If conditions permit, ある リピータ 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, カメラ, and battery?
下の写真をご確認ください. 
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 ミリ秒, 右?
私たちの 100 ミリ秒, it’s about 300 に 400.
We also have one with 30 ミリ秒, 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.
買い手: 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?
Yes, COFDM-912T supports transferring the serial data for you. 下の写真をご確認ください. 
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.
答え: 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 メーター – 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?
Hi! We did extensive testing before ordering a bigger batch. And faced issues if combining the COFDM-912T transmitter with GPS.
答え:
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?”, 答え: 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, 送信機と受信機, 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周波数.
The customer requires that the transmitter have an HDMI output so that he can transmit the received video to other devices. 同時に, 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, ご連絡ください.
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




よくある質問
- Yes, 周波数範囲は170Mhzから変更可能 (より良い 220Mhzから) 860MHzまで. したがって、260Mhz帯域でもうまく動作します.
- 送信機と受信機の周波数を同じに変更する必要があります。. 当然のこと, パワーアンプとアンテナ周波数は同じ周波数を変更する必要があります. (変更した周波数に合わせて、送信機と受信機のパワーアンプとアンテナを購入する必要があります。).
- 送受信の感度を上げるため, 周波数帯域幅は一般的に非常に狭く作られています (中心周波数 ±15Mhz, したがって、帯域幅は30Mhzである必要があります). 送信機のパワーアンプとアンテナの周波数は、必要な周波数に応じて特別にカスタマイズされます。.
- ご注文の際がお得です, please tell me what kind of working frequency you need. Our engineers will modify the frequency of the transmitter and receiver, and also modify the PA and custom antenna according to this frequency range to ensure the best sensitivity and support the longest transmission distance.
- The default frequency is 590Mhz, With 30Mhz (+/-15Mhz), you can change it without modifying the Power Amplifier and antenna. 例えば, 578Mhz, 584Mhz, 590Mhz, 596Mhz, and 602Mhz.
- If you need to modify the transmitter frequency and bandwidth, you need a special tool of the parameter configure board, please see the below picture, it is not a default accessory, please buy it at an extra cost or contact us before ordering.

Yes, it supports to send the video and UART data 送信機と受信機から.
一方通行なので, そのため、受信機から送信機に制御コマンドを送信できません。.
送信機でカメラやドローンなどの他のデバイスを制御するために、受信機から制御コマンドまたはその他のデータを送信する必要がある場合, 安価なデジタル伝送機器一式を追加できます, お問い合わせ, あなたに合わせてカスタマイズできます.

以下のリンクでトランスミッターとレシーバーの UART 定義を確認してください。. リードケーブルをご希望の場合はお知らせください。. (デフォルトはいいえです)


送信機のデフォルトのパワーアンプは次のとおりです。 2 ワット, それでサポートできる 30 視線上のKM.
下の写真は、山から海辺までのテストされた距離です。.
より長距離を送信したい場合, パワーアンプを増やすことができます. 1ワットと2ワットに加えて, 私たちも作ることができます 5 ワット, 10 ワット, and 20 あなたの選択のためのワット. より大型のアンプには、より大型のバッテリーと電流サポートも必要です.

20WPA用, 電源は24〜28Vである必要があります. でのみ 28 パワーアンプは最高の作業性を実現できるでしょうか.
当社のエンジニアは周波数をデフォルトの 590Mhz から 300Mhz に変更できます。, アンテナ, と倉庫内のPAは590Mhz, 300Mhz のカスタマイズには 2 週間かかります, そのため、納期はデフォルトの 590Mhz よりも長くなります。.

ステップ 1: OKと右ボタンを同時に押してください, 画面に保存するかどうかのメニューが表示されます.

ステップ 2: Please press OK to choose Yes to save.

思い出させる, プロジェクトで許可されている場合は、より大きなアンテナまたはより長いアンテナを使用してください。, より広い範囲でより良い受信パフォーマンスを得ることができます.

デフォルトのフルセット
- SDトランスミッター ( PA0.5W, 1W, 2W, 5W, 10W, 20W, 50W ご注文の需要に応じてオプション)
- SD送信アンテナ
- パラメータ制御メニューと小さな画面を備えた HDMI CVBS 出力レシーバー
- 0.8-メーター 受信アンテナ 1 個. (アンテナの設置・固定には2種類あります: 1. 磁気吸盤ベースアンテナ, 2. デフォルト U型クランプFRPグラスファイバーアンテナ )
- オプション, ワイヤレスビデオトランスミッター用パラメータ設定ボード.
(磁気吸盤ベースアンテナが必要な場合, 急行または運送業者が磁気製品が飛行機の安全を妨げると考えている, そのため、U型クランプアンテナよりも送料が高くなります。. )
デフォルトのフルセットパッケージの寸法
- 84*21*12CM
- 総重量 4.5KG
- 100cm以上のアンテナと磁気吸盤ベースアンテナを選択した場合, 一部の運送業者は追加料金を請求します, 延長料金や強力な磁気を帯びた商品の追加料金など.
- ボードを構成する送信機のパラメータが受信機のパラメータと異なります. パラメータ設定ボード上のファームウェアが送信機および受信機とは異なっていました, それらは同じ意味で使用することはできません.
- トランスミッタパラメータはボードを構成し、トランスミッタの信号減衰を調整できます. 0.3dbごとに0.5W PAが減少します。.


質問: 出力電力を変更することはできますか (内部PA 0,5 w, 1 w, 2 w) 構成ボード経由?

- 上で答えたように, 送信機のパラメータ設定ボードツールを介してATTENのパラメータを設定することで、出力パワーを調整できます。. (このツールにはデフォルトのパッケージが含まれていません, 注文時にこのツールが必要であることを通知する必要があります)
- 2W PAを買うなら, 0.5Wに設定できます, 1W, ただし5Wには変更できません.
- 5Wにも対応可能です, 10W, 20W, 長距離をサポートする必要がある場合は 50W.
No.
このワイヤレス ビデオ トランスミッターは CVBS カメラまたはビデオ入力のみをサポートします, 他のタイプのビデオカメラには追加のコンバータボックスが必要です.
No. COFDMです (DVB-T) テクノロジー.
したがって、COFDM 周波数範囲は 170 ~ 860Mhz です。. サポートできる 477, 610, 675, 724, 816Mhz, しかしサポートはできません 970, 1180, 1230 Mhz.
当社の特別モデル送信機は上記のすべての範囲をサポートできます, ただし、受信機はダウンコンバータブロックを使用する必要があります.
当社のワイヤレス送信システムがより広い範囲とより優れた信号強度をサポートできるようにするため, 通常、動作周波数を特定のポイントに設定します。 (170~860MHz), サポートされる範囲はプラスまたはマイナス 15Mhz のみです. 例えば, 中心周波数は590Mhzです, 最大サポート周波数範囲は575Mhz〜605Mhzである必要があります, PAとアンテナはこの中心周波数に従って特別にカスタマイズされています.
- COFDMビデオトランスミッター用, 追加のウェーブパスフィルターをインストールする必要はありません.
- 使用環境が非常に複雑な場合, 受信感度を向上させ、クラッター干渉を軽減するため, ワイヤレス COFDM ビデオ受信機に追加のバンドパス フィルターを追加して、他のデバイスの周波数によって受信信号に引き起こされる干渉をシールドできます。.
- ダイヤルスルーフィルターを追加する必要がある場合, 当社ウェブサイトの次のリンクを参照して一緒に購入できます。. 2 つの製品がうまく機能し、感度の低下が起こらないことを確認するために、これらを一緒にテストできます。.
- 周波数バンドパスフィルター
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.












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