CQ TEST G6NHU G6NHU G6NHU << They're calling

G6NHU PD4TK PD4TK PD4TK << The perfect reply

 PD4TK 599 437 437 437 PD4TK << Signal report and contest serial number

G6NHU 599 034 034 034 PD4TK << We send the report back to them

UT3ABC TU PD4TK CQ << Final message, ending in CQ because etiquette