You don't select 'TST' to get the ident function - you push the IDT' button. Which transponder do you have - there isn't a KT77 ? Honeywell's mode S unit is a KT73 and the White ident button is top left. If you have a KT76A mode a/c unit, the ident button is the small red cap below the orange Ident light.
Last edited by wigglyamp; 26th August 2012 at 09:51.