How do satellite dishes for tv (Direct TV for example) communicate with satellites when there so small and pointed at a small area in the sky?
In: Technology
Used to work for Dish Network.
So, the dish *generally* doesn’t talk back up to the satellite. It’s possible, but it requires a different dish and setup, and it’s only used for satellite internet, which isn’t what you were asking about.
It helps to think of the radio signals as a flashlight beam in a dark field. The little white lens part at the tip of the dish is called the low-noise block feed, or LNBF. *That* is the actual “antenna” and the rest of the dish is just a reflector to better focus the “light” of the signal.
It doesn’t need to be pointed *directly* at the satellite, but it’s got to be pretty damn accurate by human eyeball and hand tool standards. “Accurate” in terms of what your home garage tools can do and “accurate” in terms of spacecraft 22 thousand miles up are two *vastly* different things. The reflective dish makes that accuracy requirement a lot more flexible, and also affords a stronger signal to compensate for things like rain and clouds.
But all your receiver really needs to do is look at the equivalent of a flashlight in the sky, and determine the code from its blinking. Regular computer magic turns that really fast blinking into a data stream into video for your TV.
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