I've recently been working on a web page (still not done!) on this very subject. I've thrown together some notes and posted them
here as an Acrobat file for your viewing pleasure. Note that they're dated, disjointed, and cluttered, but they may be a place to start. If you need more let me know and I'll see what I can post. I've got a lot of material but I don't want to upload it if it won't be useful to you.
But, bottom line... near as I can tell, a VOR is a bowling pin with 361 light bulbs inside. Something to do with that and the cosine of an Alford loop array flying out of your azimuth whenever your goniometer spins...
Dave
No, not your "groiniometer," Jerricho...