WP to WP syndication question

OK, I searched around and could not find this particular issue, so sorry if it has already been addressed – anyway, I am wondering if there is a way to filter what gets “fed” through RSS. What I mean, specifically, is that I have one WordPress installation that is aggregating various feeds, plus it has content that I myself am adding to it; in ANOTHER installation, I want to aggregate only what I am posting to that first installation, and not the news-feeds that are incoming to the first installation and becoming posts … does that make sense? I have looked around with no luck, and am about to assume that my best workaround will just be a separate installation for solely the newsfeeds, but I’d rather filter out the incoming newsfeeds from the first installation, and let only my posts be syndicated to the second installation (the reason I am doing this is because I am working on a site that consists of basically three separate WP installations, and I have a 4th installation that I want to serve as kind of a comprehensive overview of all 3 WP installations, but with only the content I add manually, and not the nesfeeds I am also syndicating in those individual installs)… anyone know of a way to do this?