interference does sound like the most likely suspect.
That is a good question for which I also need to find a good answer.
We do not currently have a S-A that will go to 2.4ghz or 5.8ghz. But could also use one. I’d probably start by searching here:
http://www.dslreports.com/forum/wisp
Over the years we've seen lots of once usable links deteriorate into being unusable. And while SkyPilot looks great on paper, I'm not very enthusiastic about their real-world performance.
Last month I bought a UBNT powerstation and put SP software on it, it works, but no better than a standard SP CPE ?!?! I was bummed!
Separate subject: Who do you purchase bandwidth from? And do you have Comcast in your area?