Hi
Thats no problem I used TS-480 and Steppir a lot myself. You do not say what is not working ?. Have you made the cable from Radio-RRC com2 to the radio CAT port, thats step one. When you are able to control the radio from a PC with HRD the antenna switch will work also. When this works you make a cable from the SDA-100 to the Radio RRC com1 and you setup com1 to mode 7. If you want to be sure that the SDA-100 settings and cables are OK first connect the cable direct from the SDA-100 to the TS-480. I recomend to use the our RC-1216H for the Steppir control, but it's up to you.
/mike