Site Updates

I went through the site today and fixed several incorrect links. It seems like NASA has done a bunch more re-organizing of their sites. I deleted information on the TRACE Satellite since it was decommissioned several years ago. I also removed the Sistel Natural Radio receiver from the receiver list as it is no longer available. If anyone knows of any other commercial Natural Radio Receivers or kits or circuit boards, please let me know so I can add them to the list and provide a link.