Here are my suggestions to enhance its functionality:
1). I'd recommend http://www.tvfool.com
as the source for data instead of AntennaWeb which suffers from severely outdated station facility data. This would require a change to the color codes, of course.
2). I question the validity of this statement on the page: "NOTE: 98% of all television markets will have both UHF and VHF stations available.' Since the transition of 12 JUN 2009, a number of markets have seen total migration from V to U to become exclusively UHF such as Boston and Greensboro. A number were already totally UHF such as St. Louis, Kansas City, Omaha and quite a few other.
3). Adding a parameters (radio button perhaps?) to specify attic vs. outdoor mount would be useful in lieu of the "50%" message.
4). A selection widget to allow the user to specify a height other than the 30 ft. default would be nice.
Finally, the SQL query appears on the results page -- which I doubt you want to expose to the end user. Ti wit:
SELECT * from antenna_select where blue = 'X' && uhf = 'X' && hvhf = 'X' && lvhf != 'X' && mileage > 40 order by mileage asc
You might want to make the query ANSI compliant (in case you change the database backend) by change "&&" to "AND" as well as "!=" to "<>".