Make:

You don't.

Are you thinking of a waveguide antenna?

I think you're thinking of a "cantenna", as super_J mentions above. Lots of instructions online: <a href="http://www.google.com/search?q=cantenna">a search should turn up lots of results</a>.

Hi!

Thanks for the info but i actually want to make a real satellite dish which receives satellite tv signals. Personally, i know what a "cantenna" is and i use it for my wireless network.Is it possible to make a satellite dish out of the cover of a pedestal fan. I have added a link to the type fan i am going to use :

http://www.kdk.com.sg/product/image/200/ef/A40W-G_l.jpg

Basically, i am planning to use the fan cover as a satellite dish. Is it possible?
Also, if i want to receive free legal satellite channels using a satellite dish, do i need a satellite receiver or can i connect the dish directly to the television set?
I heard that in afghanistan, people use satellite dishes made from recycled aerosol or soda cans!

Well it's certainly an intriguing possibility but this may be going about it the really hard way. You definitely need the receiver and with the absolute surplus of dishes out there (Primestar, DirectTv, etc) you could probably pick up one fairly cheap if you have to pay anything at all.

The best posting I have seen about this very issue was in the blog back on March 26. <A HREF="http://www.makezine.com/blog/archive/2006/03/freetoair_fta_free_tv.html">It gives you all the details.</A>

sherab

Keep in mind also that there is very little traditional sattellite tv available anymore. Virtually all the signals are now transmitted digitally, so any sort of homebrewed antenna would not accomplish you a lot. There are still a few signals out there, so it's not completely useless, but don't expect to get free HBO. You might be able to get free Home Shopping Network, though.

You can get more info on available channels at <a href="http://www.lyngsat.com/">LyngSat</a>. And, yes, you will need a decoder box.

FTA satellite is basically just unencrypted MPEG 2 streams of programming that isn't worthwhile for the network to encode. Many of these channels u can't get on US cable anyway like CNN International which is a WAY different animal than normal CNN.

The problem isn't lack of programming, there's plenty of that, a bigger problem is that once u get the dish up and pointed you are limited to that bird. You really need a dish rotor as well for full benefit to swicth between the satellites.

sherab

Well, I think that's the point. Yes you can receive very little using FTA. But imagine if you could make something that could receive something without buying anything.
A hurricane wipes out your state and you need news. Cable is down, but you have power because your prepared. No satellite dishes in the area that are undamaged.

Hmmmm. I was thinking, could you make a MPEG2 decrypter using a DVD player....

I'm sure it's possible to make a homemade dish. I know that some people have made cantenna dishes out of various parabolic cookware:
http://www.google.com/search?hl=en&q=%2Bparabolic+%2Bcookware&btnG=Google+Search

So it's not a stretch to make a dish to receive FTA. Let's see, I think that the hard part would be the feedhorn and LNB

I think you are refering to the Microwave Distribution System (MMDS).
a 1 lb coffee can is a great tuned cavity for 2ghz tv. the circuit is a local oscilator mixing with the incoming RF and outputing a downconverted TV chanel.
Your antenna will be line of site to the transmitter, and above the trees, kind of tough to point but it is rumored that HBO and premiun chanels are out there.... ;)
(We had "Chanel Z" many years ago in Houston off Greenway Plaza that WAS HBO. NASA TV was broadcast (probably still is) from the Johnson Space Center)

In the US MMDS is not viable: http://en.wikipedia.org/wiki/MMDS

"Starting in 2006, MMDS frequencies in the 2110-2155 MHz range are being re-allocated for the Advanced Wireless Services"

So what about getting Microwave signals from satellites?

To throw my own 2c in, check out some of the specs for amature radio and satellites <for example http://www.amsat.org/amsat-new/index.php> and antenna's. The amature radio community has a lot of information about antenna design, etc. Try checking them out.

As weak as this thread starts, it would not be complete without mentioning SDR: software defined radio, the most exciting this to come out of computing in the last 7-10 years I'd say:

http://en.wikipedia.org/wiki/Universal_Software_Radio_Peripheral

The USRP is a box that can record entire radio spectrums to a hard disk. You can play them back and retune through them. You can get any frequency, from any source, satellite, 'radio', digital broadcasts.

Any transmission.

sounds amazing.