I'm interested in EME/moonbounce, and I'm looking at using 2m SSB or CW for it. I don't really understand the issue of polarity though. As I understand, the polarity 'can change'. VE2ZAZ has a nifty presentation online. But I don't seem to get this idea of polarity. I see antennas that have polarity switch kits. M2 makes one. And M2 has circular, dual, and some other polarity (it doesn't say) that I'm guessing is horizontal, since it is a yagi. IF I get a circular polarized antenna, do I eliminate this 'not in the right' polarity issue? Such as, does the circular polarity essentially prevent the need to switch back and forth? I'm not sure if it is dual polarity if I have to 'know to switch it' and have to do it manually, or using a circular polarity one does both without the guesswork.