regexp match question

Hi All, Here's a question I can't answer. I'm using regexp to dig out strings from data received via Ham Radio, so the txt often is corrupted. What I want to match is two consecutive callsigns separated by whitespace, for example 'hb9drv hb9drv' but not 'hb9drv hb9drX'. I can define the match condition for a callsign, but can I use the match option {2,3} somehow to match the same callsign two or three times? Effectively match the same word two or three times? Help received with much thanks, Simon Brown, Casa Bergenia, CH-7031 Laax www.hb9drv.ch [Non-text portions of this message have been removed]