PARS has built home-made Yagi and other types of antenna for tracking at 433MHz. We picked up a radio receiver off eBay, a Yaesu FT-790R. Works like a dream. Wish I could say that about the netbook we used to run FL-DIGI decoding software. The audio input appears to have a certain amount of noise, making packet decoding difficult. Ben Oxley of the APEX team helped me to diagnose these problems. Still not adequately resolved.