I've bought a CM-7777 titan2 antenna preamp and no channel goes to my tv set. If I bypass it, I can get around 16 HDTV channels.
I'tried the preamp near the antenna connectors(15 inches from the preamp). I did change cables for RJ-6, put a new 300/75 ohms transformator to my yagi Wineguard antenna.
I've measured voltage reading to the power to the preamp, it reads 21/22 volts dc so there is power there. I went to the dealer and he tried at his home and the preamp works in a similar situation.
Antenna without preamp, direct to the tv (42" plasma Panasonic) works but I know I could get 8/10 more channels.