Onus

I believe I've got a minor alignment problem on my Catrike Road. If I take both hands off the handlebars, the wheels will almost immediately begin to shimmy to the point I need to quickly grab on again (e.g. I wouldn't have time to pop the top on a soda can while moving). I searched the forum and didn't find an answer, although at work I can't access the videos in some links. My wife does not seem to have this problem on hers; she can let go and the wheels stay "quiet" and straight, so I'm thinking I've got a minor adjustment problem. I have not noticed a lot of tire wear, although I doubt I have any more than 200-300 total miles on my trike.
I consider myself reasonably competent with hand tools (I build PCs, dabble in electronics, enjoy the usual fix-it projects, etc.) so I believe I could probably handle this if it isn't too involved. Any guidance would be appreciated.