I have similar problems with the evo, s up here on the 4500.
Try setting the stabaliser down to 7, if thats no good, down to 5.
I was out yesterday, really windy, start of the day I could use the stab on 9, but still got the odd " was that a signal or just noise? "
Met up with a mate who runs a 7000, and he has similar problems as well, it just means you need to be more patient, and investigate the sounds, my mate got a signal, and called me over, I had a 14 x 9 evo on and got a sound, I called it for a nail or similar junk, because thats what id been digging in that area, and it sounded no different to me. It was pretty deep though, maybe 30cm, and it turned out to be a nice .96gm nugget. Bit later he got another target, I could not detect it at all, just sounded like emi noise, and just a slight beep, and I couldnt distiguish it from the racket that id been listening to all day, it was a .26. If I didnt have the emi/ground noise, I could have realised it was a target. No matter how quiet I get the coil, I will always get the odd beep here and there, some times seconds apart, sometimes good breaks of 30 seconds or more, but I never get a constant even, uniterupted steady hum of the threshold, and that is why im not finding the small stuff with the evo, s. The 5000 users get *** to run dead steady most of the time.
having said all that, even with emi and ground noise, constant annoying chatter, if there is a small , shallow bit, the evo sings out loud, and there is trouble identifying a target, its with the small stuff, a little deeper I miss.
The 15 spoke runs a bit quieter, but looses some sensitivity on the real small stuff.
For the record, my mate with the 7000 scored 6 nuggets to my nil......1 x .96, 1, x .26 and the rest were between .3 and .6 but too deep for me to get a clear signal on, I want a Z! But its gunna take a while to pay for one at this rate lol!
