acutally if you have two vexilars you will be fine, my wifes cousin has a fl-8 too, and we fished in a 6x8 portable with both our flashers on and all you have to do is push the gain knob in and it takes care of everything otherwise you both would see the same thing. you only need to do it to one of the vexilars not both. if you go to vexilars web page you can pull up owners manuals via pdf and go down to page 10 it tells you everything in that aspect.
Last edited by pyro6999; 01/13/10.