In another thread (do search) it was stated that you could use a Philip's RF Stereo Powered Modulator (PH61159) to feed a second TV in SD. Well mine came in today and it works great! Have HD on one TV and viewing SD on second TV at the same time. I ordered mine from Atlanta Network Technologies for less than $10! It is really a DVD converter to connect a DVD player to any TV. Go for it if you need to use coax for some reason. Good Luck!
I tried a RF converter from BB/ CC don't remember the brand,it worked but looked terrible, took it back and bought a 100 ft Conposite cable and ranit in thru the attic and hooked it up and looks great.