We had many, many email exchanges in the past about your reception problems. I am sorry, that so far, we were not able to resolve it. We had no reception complaints from other viewers from the same or near-by locations. My latest correspondence to you was on 10/29/09. I didn't receive a response, instead you choose to write to others. Your latest email was forwarded to me again as always, for reply. As I mentioned it before, we are broadcasting with 100% authorized power from our 1350' tower at the intersection of State Road 7 and Lantana Road. Our field strength measurements at the various locations, including in Saint Lucie County consistently indicated sufficient reception signals and always at a considerably higher level than that of WPEC-TV. It seems, that with all those stations available at your location and with some of the signal levels extremely high, because of the transmitters being near-by and high powered, such as WPBF among others, the front-end of your system might be overloaded. The overload can affect various channels differently depending on the relationships of their frequencies. There might be problems with your antenna also, if it can pick up CH28 in Tampa and stations in Orlando (as you previously noted) way off from the main lobe of the antenna, when I assume, it is aimed at WPTV. Fog, humidity, rain, temperature, etc. can cause considerably different receptions on the different channels also.
For your information again, during one of our field tests, reception of our signal in Palm City at the Saint Lucie County line was excellent and much better than that of WPEC's. We used inexpensive rabbit ears, only four feet off the ground and there were obstacles such as trees and houses in the signal path. I am sorry, that I am unable to offer solutions to your problem at this time. It has to be unique to your particular location, equipment, system. You may contact me at your convenience if you wish.
John Falvi, B.S.E.E.