Amend what I said in private message.
Do not install preamp for Chicago initially. Instead, install distribution amp. The Channel Master CM3418 8-Port Distribution Amp is what you'll need.
http://www.amazon.com/dp/B002M1EPL0/...ter_B00C9UJLOU.
Also if WREX is mandatory. I suggest a two antenna system. In addition to the DB8 pointed to magnetic 120 as already suggested, purchase a
HBU11.
http://www.solidsignal.com/pview.asp?p=HBU11&ss=29222. Orientate to magnetic 262. The HBU11 will be a dedicated high-VHF antenna for WREX.
You will need a signal combiner. The
Antennas Direct EU385CF-1s is a quality unit.
http://www.solidsignal.com/pview.asp...CF-1S&ss=29223. Input DB8 coax into UHF input, then input HBU11 coax to VHF input. Run single lead of coax indoors to distribution amplifier.
This will give you Chicago and WREX.
An option if reception for Chicago if WTTW is unreliable may be the RCA TVPRAMP1R as mentioned privately installed AFTER the signal combiner, however, I'd prefer to suggest a system without it for starters. Adding double amplification can be a tricky game.
SS