< > I know that Track get very touchy at 900Mcyc speeds but, I also knew t I've done RF, at that very touchy part starts at around 50MHz, by 100-200MHz coils are simple lengths and at 470mhz anything longer than 1/4" becomes significant. I did a power amp at 512mhz and the whole tuning and interconnect was all carefully calculated lengths of tracks. Even the board material and thickness was critical! I was lucky with the RF I could use one whole side as a ground plane! Oh, and quarter wave lines at operating clock speeds is a real nasty. < It helps to have some idea of RF and microwave design before attempting < to build a 1GHz circuit. Otherwise you are wasting your time. This is no < something you can fiddle with until it works unless the underlying < design and layout is sound. Like Tony said, guessing will have you making whole new baords for small changes. Allison