Introduction: Transmitting Stereo Digital Audio
This will show you how to transmit studio quality stereo digital audio around your house and beyond if you have a powerful enough transmitter.
Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.
Step 1: Things You Will Need
You will need:
A video transmitter and receiver. The lower the frequency the better. I am using one that transmits at 1080 MHz. I purchased the transmitter on its own as I already had a receiver from a wireless camera which burned out because I thought 30v would give more power.
Two coaxial cables to connect everything
Power supplies or batteries
An spdif to analogue converter I got one for £11
Earphones or an amplified speaker
A computer or other device with a digital audio out coaxial connection
Step 2: Connecting All the Devices
You will need to connect one of your coaxial cables to the digital audio output on your DVD player or whatever you are using. The other end is connected to the video input on the transmitter.
Plug a power supply into the transmitter. I use a 9v one because 12v makes it heat up too much.
Plug one end of your other coaxial cable into the coaxial input on the converter box and the other into the video output on the receiver. The converter box I have is 5v and the receiver is 9 to 12v.
Plug earphones or your speaker into the audio output on the converter box and then plug in the power for the box.
Plug in the power for all devices and play music on the stereo. If you are using a computer with digital output, you need to go into your playback devices and select your digital output. You also need software where you can select the playback device I have Realtek digital output. I have it set to 2 channel, 24 bit 44100Hx studio quality. This lets me get to the other end of our old farmhouse through thick walls before the signal starts to break up. If the signal breaks up, select a lower quality setting.
Step 3: Tuning In
Tune the transmitter very carefully. As it is a digital signal, the dial on the tuner needs to be exactly on the right frequency. Turn it very slowly until you hear music. You will notice if all goes well, that the quality is as if you were sat at your computer with headphones on. The transmitter that I am using had 800mw written on the box even though I had oredered a 500 mw one so chances are I am running at under 500 mw.
Although these little transmitter kits appear to be designed for video only, they are actually just very wideband radio equipment which can be used to transmit anything you like. The lower the frequency, the better as you will get better range through walls with lower power. Do not go for the 2.4 and 5.8 GHz rubbish as those are really only useful for FPV on model aircraft.
Another interesting use may be a high speed serial link if you were to connect a USB to TTL converter to the video input of the transmitter and on the receiver end, you would have an amplifier to bring the signal up to +5v so the other USB to TTL converter could decode the signals.