Tired of the blocky, JPEG-like resolution of digital television? Do you long for the days of RF modulation and regulated-yet-unregulated content? Do you simply have the desire to toss your converter box out the window and make use of those rabbit ear antennae that are just lying around? If so, then you might be interested in becoming a savior of analog television! This Instructable will show you how to create your own fully-fledged low-power analog television channel, with any video source(including your computer) as a source of content.
We created one that went live the minute analog tv went dead. We're still the only analog station in NYC, but please join us in making more!! Long live analog tv.
Step 1: Find a Free Channel.
The first step is to find a TV channel that isn't being used in your general vicinity. Although after the 2009 DTV transition in June a lot of "whitespace"(i.e. unused television bandwidth) became available, most of this whitespace is still legally dubious and many of these channels are still tied to the original owners via legal identity and copyright. However, because of this legal ambiguity a lot of free space is still up for the taking.
The best option for finding free space is the FCC's own search engine for these things:
Simply type in the channel (try a range of 14 to 35) and your state, along with the type of broadcasts available. Try to avoid channels that correspond to channels in your area (i.e. CBS 2 in New York). While they might be free because of the DTV transition and broadcasting in a higher channel range, they are still virtually broadcasting through that channel and might also have dibs on it for visual identity's sake.
Step 2: Find a TV Transmitter.
The next step is to find a good transmitter. There are a myriad of ways to go about this, but these are the three best ways we've come across:
1. buying multiple short-range consumer transmitters
2. commissioning a transmitter from Free Radio Berkeley Http://freeradio.org
3. building your own
The first is relatively cheap-yet-clumsy, the second relatively expensive-yet-simple and the third a bit less expensive but a (rewarding) challenge, but all three result in a rather robust analog broadcast.
Step 3: Step 2, Method 1: Multiple Short-range Transmitters
This method is essentially an ad-hoc broadcaster made up of lots of tiny, low-power wireless UHF audio/video transmitters. These can be bought fairly cheaply on eBay, and have a range of about 500 feet:
Most of these transmitters require an RCA composite or Coaxial input, so any video source would work. To get composite video from a computer one simply needs to buy some kind of VGA/DVI to Composite converter or a PC TV converter, which usually range from 35 to 200 dollars, depending on the quality.
The channels that these transmitters broadcast on are also adjustable; see the transmitter's instruction manual for details on that.
Networking the transmitters can be achieved by daisy-chaining the antennae with the Coaxial In/Out ports on each transmitter using long, 500-foot cables.
Step 4: Step 2, Method 2: a Commissioned Free Radio Berkeley Transmitter
The second method involves purchasing an used transmitter on ebay ( everyone is dumping them now that the digital transition has happened) or getting a custom-built transmitter from Free Radio Berkeley ( www.freeradio.org). Their site has instructions for purchasing a pre-built NTSC or PAL TV transmitter, amplifier and antenna. While more expensive than the first method, the final transmitter is more powerful and dependable than the makeshift transmitter network.
Like with the previous ad-hoc broadcast method, any analog video source will work. However, if you plan on using composite video you will probably need some RCA-to-coaxial converters for the video and audio, which are really just a few bucks at radio shack.
Stephan Dunifer, the founder of Free Radio Berkeley, has been building these transmitters for the past thirty years and is very helpful if you have any questions.
Step 5: Step 2, Method 3: Building Your Own Transmitter
This method is pretty intense, but doable for the electronics folks .
In 2008 the media collective !Mediangruppe Bitnik created a freely-downloadable pocket zine that contains detailed instructions for creating your own short-range television transmitter:
This transmitter also accepts any analog video source you can throw at it.
Step 6: Install Transmitter
It's important to find a good place to setup your antenna. You want to find a high location that can transmit waves relatively unobstructed. Chimneys work great.
Long runs of cable between your antenna and the transmitter will degrade your broadcast range, so the shorter the distance the better. We decided to put our transmitter up on the roof and run the A/V cable up from our broadcast room.
In order to protect our transmitter from weather and rain, we bought a huge tupperware container and retrofitted it with holes for ventilation and cable runs to house and protect the delicate electrical components.
Step 7: Step 3: Content!
Content is key! Once you have your transmitter set, there are infinite possibilities for your new TV channel. You can use anything analog--old home video tapes, video cameras, character generators, etc.
If you're using a computer as a video source, your possibilities are potentially more infinite. However, if you still feel scraped for content there are various webscraping tools at your disposal, including Yahoo Pipes, Google Mashup Editor or Youtube's own API. Enclosed is a flow chart that explains our approach.
We create our own custom web scrapper at http://OMGimon.TV. We're happy to share our code if you're interested in building something similar or building a webscraper.
Step 8: Now Stare Into Your Tv Screen....
Nows the fun part. Sit back and relax and watch your tv station, without flipping through youtube's endless options or 1000's of mediocre cable channels.
Darzen made it!