Greenfield Antenna Recommendations?

[Scott Zsori]

I just purchased a new house close to 27th and College and was curious about people's experience with different antenna types down here.  I'm currently getting my HD from TWC, and would like to save a few bucks each month since we only get the local channels and just dropped Road Runner .

I looked on http://www.hdtvpub.com/local/viewOTAReports.cfm/group_plasma-hdtv/zipcode_53201/dma_617/ and found some info, but I'm curious what signal strengths are acceptable for OTA.  When do you notice loss of picture and sound?

I also looked up my address on AntennaWeb, and it recommended a medium range omnidirectional.  I'm looking to get the ABC, CBS, and NBC HD channels.  I'd also like the SD Fox, WB, and UPN channels (since Fox HD content is garbage now, and I know the tower is being worked on).

My house is a 1.5 story (finished attic), and I'd prefer not putting up a mast antenna.  My 48" mitsubishi is in my basement, so it'd be a good 40' from the antenna down to the receiver.  Don't have a receiver now, but the commander (my wife:))  will approve me getting one if we're saving on our monthly cable costs.

Can anyone down in this area recommend a setup?  Any possibility of picking up WB HD from Chicago without a mast antenna?  Thanks in advance!