how can I build a Wireless Display/Transmitter that don't need a receiver?

On my school's cafeteria there are 3 big HDTVs. What I wanna do is, at lunch time that everybody in in there, hijack the 3 tvs' signals and replace them with a funny video. (Also, later on I can use it on my own house)

I don't know if you've heard about those headphones that you put on and they catch the signal from the nearest TV so, at night when everyone else is sleeping you can listen to it without disturbing people. I was thinking about using something like that! Of course, doing the opposite. I don't know what's the 'official' name. Some people call it a 'low power transmitter' and other people call it 'Wireless Display (WiDi)'. Hopefully you'll know and if you do, please let me know.

I just want SOMETHING like the iTrip, you know? That the radio station IS the receiver so I won't have to build the actual receiver. I want to build/buy a transmitter that will adapt to my laptop or my iPhone so when I click play on a video, it will show on the nearest TV or TVs without the necessity of them having a receiver. That the actual TV, tv's signal, channel, whatever IS the receiver so I can carry it around without the necessity of putting something on the other end whenever I wanna watch something on a different TV.

I'm really hoping I made myself crystal clear and didn't confuse you. I'm also hoping you could give me your advice, or if you have a better method.

Your talking about the Load and Clear. It is a very sensitive microphone that is able to amplify the sound from the TV. It doesn't disturb the other person cause the TV audio is set low and the device amps the sound up so you can hear it.

The TVs in your cafeteria are CCTVs (closed circuit Television). Meaning they are wired to a computer or some video player. No signals are being transmitted to the TV over wireless and the TVs are not transmitting any signals out. Only way you can hack the TVs is to gain physical access to the player or the cable going into the TVs. Which could put you into allot of trouble.
madcap17 (author)  mpilchfamily4 years ago
thank you for the info. I appreciate it. the TVs on my cafeteria are actually normal TVs, they have cable so, the staff always put cnn on all day or other news channel. it's ok from time to time but they never change it. I thought it would be cool to prank the whole cafeteria and during lunch time hijack the signal. guess it's not really possible, huh? maybe not for CCTVs, but do you happen to know if I can do it with a normal TV. maybe not for the ones from my school, but the one from my home.
A cable is still a physical connection, there is no signal to "hijack". You would have to physically interrupt the cable. I assume that these TVs can be operated with universal remotes. You could build a little IR transmitter that turns the TVs off or changes the channels. The same thing goes for the TVs in your house unless they are wifi enabled but even then I'm sure there are precautions in place to prevent unwanted signals controlling the TV.
Be careful though because if you push any of these pranks to far they will just take the TVs away for good. When that happens your actions have negatively impacted every other student and if someone finds out both the staff and students will not be happy with you.