I have my 433 Mhz transmitter and receiver placed less that 5 cm apart, yet nothing can be transmitted between them. I have followed a wiring guide and checked everything at least 5 times. Does anyone know why they aren't sending any data?
No, sorry .
My crystal ball and my oujia board are both out-of-order right now.
You have followed the wiring guide incorrectly.
You have the wrong power setup.
The code you are using is wrong.
Your transmitter and/or receiver are broken.
I can't see any of those things so you can pick the one you prefer.
BTW how do you know that nothing is being transmitted? Perhaps lots is being transmitted but none of it is being successfully received.
Steve
Hi,
Welcome to the forum.
Please read the first post in any forum entitled how to use this forum.
http://forum.arduino.cc/index.php/topic,148850.0.html then look down to item #7 about how to post your code.
It will be formatted in a scrolling window that makes it easier to read.
Can you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png?
Can you post a link to specs/data on the Tx and Rx?
It might also help if you place the Tx and Rx about 30cm apart.
Thanks.. Tom... 
Does anyone know why they aren't sending any data?
Are they each connected to Arduinos, with programs to transmit and receive data?
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You must use a program that actually sends a pattern of data, and on the receiving side, something that can pick that data out of the noise. Those modules (the ASK/OOK ones) use automatic gain control, that is, they adjust the sensitivity and threshold to get a ~50% duty cycle output. If there's no signal, it will amplify the noise until you get 50% duty cycle gibberish. Use a library unless you've got a severe case of NIHism and a lot of patience.
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The green receivers with that little plastic thing with a coil in it are trash. Any time you see that little plastic thing with the adjustment screw and coil visible, the receiver is garbage (not that a receiver that doesn't have that isn't garbage, just - none that use that are any good). When used at short range they can get into an undesirable state where you get no signal out no matter what you do, but powering them off and letting them sit for a while can fix it. Don't use those. Get the RXB12 (or RXB14) - they're really cheap, based on the synoxo SYN470, and when I tested all the receivers I could find a few years ago, they beat the stuffing out of the competition. Not just the $7 RXB6 that looks all pro with the little shield, but the $50 domestic made one that was supposed to be really fancy. And they worked to well below 3.3v (I was at one point simulating dying batteries)
The green transmitters are fine. The STX882 performed a little better though. Those lovely looking ones with the castelated pads, rectangular silvery SAW filter and SOT-23-6 IC, however are terribad. I tried to test the range of two receivers with that as the transmitter, using the park across from my GF's apartment, but by the time I got across the street, neither of them worked. With the STX882 and RXB12 back in the day, I had transmission range of IIRC over 1000 feet line of sight.