FCC rule is as follows. Foreign Amateurs who wish to operate in the US may do so if the country of which they are a citizen and amateur licensee has entered into a bilateral or multilateral reciprocal operating agreement with the US. Such agreements can include a reciprocal licensing agreement, CEPT license, or IARP permit. No additional permit is required -- simply bring your original license, issued by your home country when you visit the US; and be sure to identify your station while operating by the US call district identifier (e.g., followed by your non-US call sign.W3/G1ABC).
MyCall field of RF header is 7 characters + 1 character. How to set up the MyCall? I think every CEPT country has same problem. If you solved this, please let me know. Satoshi 7m3tjz/ad6gz