Scruit 0 Posted March 2, 2009 I would like to broadcast a video image to a portable handheld TV that I have. Are there any devices that will take a composite video/audio in, and broadcast them short-range so a TV can pick it up with it's antenna - no special receiver? I only need to broadcast the signal about ten feet. This idea is that rather than install an LCD screen in the car to display the dashcam output, or install a small screen using a GPS mount, I'd rather have a handheld TV that I can put in my glovebox. if I need to review the dashcam then I take out the tv from the glove box, turn it on to the right frequency and... Basically I need the TV equivalent of an FM modulator. Share this post Link to post Share on other sites
scorpion 0 Posted March 2, 2009 We have 434MHz transmitters, or channel 59 UHF "modulators". Be very careful choosing these devices! Imagine the difficulties with wireless analog cameras, and you can imagine the diificulties playing with these devices. Most of the devices will come with a 9 volt battery clip. If you power the device with your power then be very, very careful with reverse polarity. They will blow faster then you can blink your eye! Use a diode to protect from reverse polarity. The T-59 version are not weather proof, and you have to be carefull how you package them as you do not want to trap any "ANY" heat at all. The 80mW version is just a heat shrink wrapped pc board. There is a version in a metal case. If you are using a TV set then do not use the "Rabbit Ears". You need to use the antenna that is shaped like a bow tie. You older folks know what I am talking about! http://www.radioshack.com/product/index.jsp?productId=2062017 For those of you who are testing these with your home TV then disconnect your TV from any cable box, or sat box as you will not receive the transmitter video signal as it does not pass through the box. Most will have about a 80mW transmitter, and if they brag about a mile distance then do not believe it. Anything close to one watt is going to need an FCC license. Be advised that most TV sets of today will have weak UHF reception. The tuners are not built with any regards for UHF. If you can find "granddad's" old tv with a rotating UHF knob then the better! You can use any camera that you wish, and you can plug the camera video out in to the transmitter. You can wire the "bumper" camera in to your trunk, and then connect to the transmitter. You do not have to worry about how to package the transmitter, and you can reduce the auto 12 volt down to 9 volts. Having the transmitter inside the vehicle will help with the reception as you do not have to penetrate the signal from outside the car through the metal in to the inside of the vehicle. Most modern day cars tend to have the fold down seats between the trunk, and passenger compartment. Video Comm is one of the recommended brands. NOTE : UHF transmitters operate in the Amateur Radio Service (ARS) frequencies, and according to FCC regulations, requires licensing for legal operation. There are no restrictions on the sale of this equipment, however ScorpionTheater urges the user to become familiar with and observe all laws and regulations governing ARS licensing and the operation of ARS equipment. Please note that the ARS frequencies are not for commercial use. ARRL http://www.arrl.org/FandES/field/regulations/bandplan.html FCC http://www.arrl.org/fcc/uls101.html http://scorpiontheater.com/uhf.aspx Share this post Link to post Share on other sites
