If you don't need to use a separate VHF antenna, consider the 10G201 or RCA TVPRAMP1R.
http://www.amazon.com/RCA-TVPRAMP1R-...=cm_cr_pr_pb_t
Be sure you've got the antenna aimed correctly... You may not need an amplifier at all.
Tivo tuners seem to have a reputation for being poor at over the air reception... that might be helped with a preamp.
Some surge protectors are also trouble makers, I don't use them as a 'first line of defense' when grounding my antenna system. I do the grounding outside...
http://forum.tvfool.com/showthread.php?t=901