I have an old small satellite dish (about 24 inches),and was wondering if I can remove the LNB and replace that with a hand made TV antenna.No Im not connecting that to the sat receiver.I would like to connect the dish to my digital converter box (over the air TV).Why would I want to do that you ask?Because the dish is basicalley a signal reflector and this should collect a better signal and reflect it to the hand made tv antenna,where the old LNB was.I know I cant point this thing up into the sky and is considered a directional antenna,so I would point it level twards San Diego,where all the TV stations are located.Would this work?Thoughts?Ideas?...........Thanks.

That basic concept is a pretty common mod to USB wi-fi adapters (using a colander or whatever). It should work, but dont expect miracles out of a home-cooked set-up. There are some pretty good (and inexpensive) amplified antennas commercially available that will do a much better job.

I have a friend that is an electonic engineer. I gave him an old satelite dish and he was able to use it to pick up a WiFi signal from a Starbucks that was about half a mile away. He had to mount it out his 2nd floor window and he had line of sight to the coffee shop.

Your idea should work as well but keep in mind that such a dish is only going to be good for signals from that specific direction. If you are recieving signals from several different directions, then a dish will be very limited.

I think that, with a 24" dish, you are going to have a hard time receiving anything that has a 1/4 wavelength of 12" or less. Probably anything under ~150 MHz is going to suffer. Probably will work okay for frequencies above that. (I'm guessing that channels 7 or 8 and above will work... okay.)
All based upon an educated SWAG.