David, The 6M repeater offsets here in the US are either 1.0 or 1.6 MHZ. There are exceptions, but not many. A duplexer for only a .5 MHZ frequency separation would be difficult to build. 73! Ken Kopp - K0PP Montana VHF / UHF Frequency Coordinator ElecraftCovers at gmail.com On Tue, Dec 14, 2010 at 1:50 AM, David Pratt <david at g4dmp.fsnet.co.uk> wrote