I really appreciate the quick response I am getting in this forum. Like I said I have been battling this for almost a year. Since I have had 2 5n1 sensors and now the second bridge and still have the same problem, I think it is time to relocate the sensor to my wife's flower garden and out of my vegetable garden. and try that first because I am more comfortable with moving it than I am with disassembling the bridge and making modifications--I'll save that as a last resort. As long as I can get 2 bars, I'll feel like my signal has some sort of cushion. I just wonder if anyone out there actually gets 4 bars without having the sensor in the same room as the bridge.
I assume some do. However, RSSI doesn't make a very good distance indicator in the real world as there are other factors involved.
As for the antenna, people think they can just add an external antenna and everything will be hunky-dory, ignoring the fact you might just be over-loading the front-end of the receiver with more noise.