Today I bring you yet another review of a product DealExtreme, é um Transmitter and Receiver Kit Audio Video Wireless 2.4GHz (2.4GHz Digital Wireless Audio/Video AV Transmitter & Receiver Kit). This kit, manufactured by Gadmei, model VC-2400 allows you to transmit video and stereo audio wirelessly, from a DVD player and / or a satellite receiver (Sky, etc.) or any other source of audio / video you want to a TV located in another room without the need to run wires.
Can also be used in security systems are connected to a camera, The transmitter has two sets of RCA inputs (composite video + stereo audio), one directly on the device and another through a mini-din plug, já adapter cujo vem even. At receiver you can select between two input through a switch.
The kit operates in the frequency range of 2.4GHz ISM, with 4 channels to the user's choice, which is useful to try to find a band that is not being used on site and avoid interference with Wi-Fi, etc. The kit also includes a remote control extender, so that the remote control signal is transmitted from the receiver to the transmitter, allowing use of the remote satellite receiver, DVD player, etc. to control it despite being in another room. The infrared transmitter operates at 433MHz band, and is apparently independent of audio and video transmitter, including having a separate antenna.
All color system are compatible with the apparatus, including PAL-M Brazil, and NTSC, PAL europeu, etc. Neither the site nor the manufacturer's manual indicates that this device is digital, which would imply a chip to capture video at the transmitter, encode it to MPEG or something and transmit it digitally to the receiver, it would have a decoder. That would be ideal, to save bandwidth and introduce more robustness to noise. But this device definitely does not do that, and do not even know any device that does, certainly cost you dearly, so this digital title seems to be a journey of DX.
The only solution is hardware and plug-n-play, there is no software to be configured and adjustments are simple, at least with respect to the buttons in the apparatus, therefore the position of the antennas is laborious.
The kit comes with two sources bivolt, that accept input 100-240V 50/60Hz 60mA and, and so it works anywhere in the world without major problems, provided there is an outlet adapter plugs to connect the American standard (those of two blades, very common in Brazil along with redondinhos). The output of 5V adapter is like 1000m, But I doubt really as lightweight adapters can provide 1A, but this is no problem as both the transmitter and receiver need only 5V 200mA.
Also included in the kit two triple RCA cables, one for the transmitter and for the receiver, plus an adapter that lets you connect a second audio source / video transmitter, using an RCA cable more (não even). The manual that comes with the unit is in English, a great advantage for those, I like, can not read Chinese. And who can not read English also need not worry because the installation is trivial and anyone who has ever installed a VCR / DVD will be able to do it.
The challenge here would be to make the transmitter / receiver coexist amicably with other devices using the 2.4GHz ISM frequency band, mais especificamente um roteador 3Com OfficeConnect Wirelesss 108Mbps 11g Cable/DSL Router, 3CRWER200-75 model, padrão using or IEEE 802.11g, beyond the scope Super G, which increases the speed of the apparatus theoretical 54Mbps (limit do 802.11g) for theoretical 108Mbps, by a technique which uses two channels Wi-Fi while. For those unaware, the standard Wi-Fi 802.11g divides the 2.4GHz band in 11 channels (13 or 14 In some countries) 22MHz bandwidth with, But there is overlap between the channels, so that it is only possible to have 3 Wi-Fi networks without overlapping frequencies (channels 1, 6 and 11). In the particular case of Super-G, it is fixed in the channel 6, whose center frequency is 2,437 GHz, but the minimum and maximum frequency channel (2,426S 2.448 GHz GHz, respectively) certainly are not respected because of the channel bonding. The figure below (withdrawal hence) shows how the channels are divided Wi-Fi on the 2.4GHz frequency band:
In addition to Wi-Fi router Bluetooth devices also exist: cellular, dongle in the PC and printer, they are even more challenging because the Bluetooth divides the ISM band at 2.4GHz 80 channels, more uses all eles, jumping quickly from one to another to avoid interference from other devices, consequently causing interference also a beautiful. 2.4GHz cordless phones are also a problem, but I have no.
The distance to be bridged is about 4 or 5 meters only, but a brick wall, a closet and several objects to be implemented in the way. The result is good, interference with any, but it was quite laborious to find the optimal placement of equipment and their antennas.
The device has 4 channels, there is no information on the manufacturer's website or in the manual which is the frequency range that each channel uses, Similar devices but using 18MHz bandwidth channels with, with center 2413 Mhz, 2432 Mhz, 2452 E Mhz 2472 MHz for channels 1, 2, 3 and 4 respectively. Thus the channel 2 the kit is what suffers most from the interference of Wi-Fi channel in Super-G 6. Then the channel 3 the kit also receives a certain amount of interference. After a series of tests was still in doubt about the channels 1 and 4 do kit. O canal 4 is relatively free of interference from Wi-Fi, while still giving each pipocos when it is in full use, But it suffers from too much interference from microwave (they also use the 2.4GHz ISM band), when it is switched. Já o canal 1 Kit hardly suffers interference from microwave, but suffers some interference from Wi-Fi, but only when there is actually data transmission, in other words, the simple fact of the router is connected and making the SSID broadcast does not cause interference. Although some users have reported that their routers crash and require a reset if used along with these audio and video transmitters, this was not the case with my 3Com, not only continued working perfectly, as it seems not to have suffered any drop in speed or signal level with the transmitter on, but that I still have to look more closely.
O Bluetooth, as eu já mencionei, uses the entire 2.4GHz ISM band, therefore change the channel on the transmitter does nothing, but fortunately it only causes interference when actually transferring or looking devices, what is not so constant and so bearable.
I decided to do a test with a much larger distance, near 15 meters and 3 or 4 walls to be traversed, inclusive tranversalmente. Already counted including only receive noise, but I was surprised with the result, that without much effort showed an image slightly drizzled, but colored and a sound with a little noise, perhaps with some optimization channel / position / antenna was able to use it perfectly, but do not waste time with it because it was just a test. Apparently my current setup does not suffer with distance, but because the receiver is in a place very ungrateful, unless 1 metro do PC, do roteador Wi-Fi e de dongles bluetooth, and with a microwave oven also less than 1 metro, separated only by a wall (which also prevents me from using CRT monitors with the oven on because of interference, LCD in there this problem).
The receiver (white) should be positioned so that the window is visible red translucent to receive infrared signals from the remote control. At the top there are three buttons, one for changing the AV source connected to the transmitter (between the two available), the second to turn on and off, and the third to toggle between 4 channels. Back have RCA outputs composite video and stereo audio, to antenna, input source and a small antenna wire that serves as the remote control extender.
The transmitter device (black) has three infrared-emitting LEDs, two on the translucent red, pointing down, and one at the rear, beside the antenna infrared. According to the manual, position preference is to put it in front of the unit source A / V, for the LED rear transmits the signal. Alternatively you can put it on the source device A / V, leaving the red translucent out, so that the LEDs inside able to send its signal to the receiver of the apparatus, that will give front na. This is the configuration I'm using and it works perfectly without any lag and transmits all remote control commands from Sky without major problems. At the top of the transmitter have the same buttons receptor (change the A / V source, on / off and change the transmission channel). Behind also have the 3 RCA inputs, and a mini-DIN input which provides an adapter for connecting (even) whose output more 3 RCA inputs for a second A / V source. The antenna transmission / V (2.4GHz) and the transmission antenna of the remote (433MHz) are also present.
In short, the unit is doing its job, that is transmitting the signal to another TV Sky (Slave Point), noise may appear on behalf of other devices on the same frequency, but there is a constant. Somehow I'm studying to improve his antenna, maybe something to make it more directional, solutions as popular as Bombril the antenna work well in some positions and eliminate the interference quite. Basically I can say that those who have no other devices on the 2.4GHz band can use it without problems, while people with devices in these bands may have a little work to find the optimal channel and optimal positioning of equipment and antennas, does not seem, but the variety of combinations of positions of the antennas is quite large. If tranmissor and receiver are not near Wi-Fi router (as in my case) it may be easy to find the ideal position. Who wants to give up channel bonding and other extensions of 802.11g (and perhaps the 802.11n) you can safely use the channel 4 do kit e o 1 do Wi-Fi, ou o 11 do Wi-Fi e o 1 do kit, so both are well spaced spectrum in the 2.4GHz.
Currently there are several of these kits transmitter / receiver in DX, of various brands, some even power up 3In, like that of Bada, but I do not think he really gets to both, and if chegar serious ilegal, since the limit in many countries (I believe that Brazil also) tranmissão limit the ISM band at 2.4 GHz 1W. Nor is it good to use power beyond what is necessary to overcome interference, since this easily harm other equipment. Besides that Bada has no remote control transmitter, um major drawback. Currently, the single device in DX also has remote control extender that is here.
And now I will talk about the purchase itself: She was held on 19/01/2009, but account of Chinese New Year was a DX without the kit in stock (the factory was on vacation) and thus sending only been done even in 11/02/2009. It arrived in Brazil in 16/02/2009. In 19/02/2009 came the dreaded “CTE INTERNATIONAL ORDERS – SAO JOSE DOS PINHAIS / PR” no rastreamento, indicating that the product was doubtless taxed, or that is happening with almost all packets sent to the interior of São Paulo. See the trace output:
|26/02/2009 11:56||AC [REMOVED]||Delivered|
|Recebido by [REMOVED]|
|21/02/2009 10:13||AC [REMOVED]||Waiting withdrawal|
|20/02/2009 16:21||CTE CAMPINAS – VALINHOS / SP||Routed|
|In transit to AC [REMOVED]|
|19/02/2009 15:43||CTE INTERNATIONAL ORDERS – SAO JOSE DOS PINHAIS / PR||Routed|
|CTE transit Em CAMPINAS – VALINHOS / SP|
|16/02/2009 20:38||BRAZIL – BRAZIL / XX||Awarded|
|Received / Brazil|
The notice of Correios just came 1 day after I have fetched the package, and the notice of withdrawal Waiting for the day 21 actually only appeared in the system today, day 26. The value declared on the package was 40 Hong Kong dollars, and the description “AV Equipments”. The supervisor did not believe in declared value and put 30 value dollars as tributável, or equivalent to R 68,16, By raising and imposed serious or R $ 40,90, aliquot under absurd 60% (Brazil could only be). As the real value of the unit is just over 50 tax dollars ended up leaving about 30% do valor, so no use complaining. The tax this time there was the famous Paulão, but such an Orlando, actually someone did it for him, since it has a “p/” before his name. The package was not opened, and the description in the NTS came as “part”, I've never seen anything as specific :). I conclude that the values are arbitrated only by “face” packet (size, weight, etc.) and the description that puts DX. And there really is no standard, already refereed taxable value as 100 Hong Kong dollars, and then 150 HKD, and now abandoned and placed HKD 30 USD. Unfortunately these values are rising arbitrated only and there is no indication that the SP will return packets to pass through more lenient Federal Revenue Inspectorate of São Paulo, it was far more tolerant and rarely taxed these small packages.
And I close my review here, concluding that this Transmitter and Receiver Kit Audio Video Wireless 2.4GHz Gadmei's was a good buy and is fulfilling its role. O valor, even with tribute, is still lower than it would cost a similar device here. If you also want to shop in DealExtreme, directly from Hong Kong, click here and good shopping.
Update (25/02/2010): added Instruction Manual in English from Gadmei GM2400.