We don't want another bill for a phone line when we don't really need it, so I had the idea to build a cell phone repeater. This handy little device has two antennas and a bi-directional amplifier. One antenna is outside the house, probably on the roof. This picks up cell signals and sends them down to the amplifier. This routes the signals to the internal antenna at a low wattage (enough to cover our 2400 square foot basement). The internal antenna picks up the signals from our phones and sends them, through the amplifier, to the external antenna and into the network.
First question: How would I go about making one of these? I would imagine I could pick up the materials for under $150 from Radio Shack, and I'm pretty confident I could solder one of these together. But I can't find any plans. I googled for them at work yesterday, but all I could find was people who wanted to sell me one... for at least $500. And I couldn't find personal ones, just commercial ones that cover 20,000 square feet. (I don't really need it outside, since we actually get pretty good reception in the backyard.)
Second question: Would I be breaking any laws doing this? I wouldn't think so, since I'm using very, very low wattages (maybe a 5-10X stronger than a cell phone on the external antenna, and about the same as a cell on the internal antenna). And I'm not providing a service, just amplifying a signal to provide myself with better service (which I'm pretty sure T-Mobile wouldn't mind, since everything else about them is perfect).
Third question: What about a passive repeater system? According to this page, they don't work because the signal strength from the tower is so low. But they're also the people who want me to give them $650 to get reception in the basement. This would be even cheaper than hacking together a BDA, since all I'd need would be two $20 antennas and $5 of low-loss cable.
Fourth Question: What about this thing? Could I add a transceiver to the phone connector to make a BDA? I really, really, really want to avoid having to plug my phone into something. The antenna connector on my phone (T610) is underneath a little button, and I have to turn off the phone, open the battery cover, remove the button, plug the antenna cable in, and put it all back together. And what's the point of this when I got a cell to not have cords?
If anybody could answer my questions, that would be great. Circuit diagrams or instructions would be excellent. The only ones I could find are for a wired 2.4GHz signal booster, not a repeater.