Can anyone tell me the differences between the flat box antennas by RCA: model 1400, model 1450 which has an amplifier, the 1500 "superior" box, and the 1550 "superior" box with amplifier. They also make a model 2000. What is the difference between all these; I would think the 1450 or 1550 with the amplifiers would make it "superior." Right now I have an old box tv with a connection to an indoor rabbit ears antenna and a converter box, and the setup works pretty well, but I don't get Channel 13 (PBS). So was wondering if any of these flat box antennas would give me more channels. I can't seem to find the information from RCA at their website.