Yep, that's what noise cancel is for and is really a great feature on the FBS machines. On my GT I have only two noise bands to choose from. Rarely though do I need to switch bands. I usually just compensate via lowering sensitivity. I don't like switching bands anyway, because on the GT using band 1 will make some mid conductor targets read slightly off what it says on all the VDI charts for things like nickles. The prior Sovereigns that didn't have the ability to switch noise bands were on band 2 I guess, and thus all the charts out there match on the GT only when you are in that band. That's why I always stick with it.
This is also a problem with the FBS machines. I recently saw a thread where a guy tested the VDI of targets using various noise bands. He was shocked to not only find some mid conductors had changed in VDI somewhat, but in fact some coins did as well. While I always knew this was an issue on my Explorers, I never carried out thinking what the consequences of that were until he mentioned it. If you develop a specific discrimination pattern using learn accept/reject, that can somewhat be rendered a useless pattern if you then noise cancel and you end up being on certain other noise channels. For that reason, many people do in fact stay on the same channel that they "like" and never noise cancel again. Just so they get used to and know the particular VDI #s for certain targets well, such as nickles. Also, some believe certain bands hit harder on certain targets. In this thread this guy found that to be true for him, so he concluded that some bands might be used for say silver hunting, while other bands might be prepared for gold rings. I'm sure that if it's even true there is even a difference in that respect it's probably very slight, though.
I have three local Etrac friends I hunt with and at least one of them seldom noise cancels for that reason. However, when a site is really loaded with EMI, such as heavy power lines right over head for us, he will noise cancel then if he sees his Auto+3 sensitivity level is riding pretty low due to EMI. When he does that things are quiet as a church mouse for him and sensitivity starts riding high again. That's when I envy his ability to do that, because I'm forced to just drop sensitivity until my machine stabilizes. Luckily those kinds of sites for me are pretty rare, and I can often ride full blast sensitivity thanks to the incredible stability of the 12x10 coil.
I'll add one tip for you guys...If you hunt with others who have other machines. Doesn't matter what brand or make they have. If you plan to hunt close to each other, let them turn on their machine and stand right next to you while you do a noise cancel. When we are going to be in close proximity to each other my friends will do that so that we can be rather close to each other and not interfere with each others machines. I've even read of guys who do this with certain pin pointers. They'll turn them on and then noise cancel, to insure no interference takes place.
PS- I have read where some will stick their coil up in the air in front of them when noise cancelling, and the way they do it the coil is more in a vertical position rather than the normal horizontal hunting position. Those of us old enough to remember playing with the rabbit ears on a TV to get the best signal know that antennas have a directional aspect to them. For that reason, when you hold the coil in the air I would keep the coil in the same horizontal orientation it will be while hunting. It might be that when turned vertical it isn't picking up certain EMI as well and so doesn't block out those channels, but when returned to hunting position that particular EMI on certain channels gets stronger, thus lowering what ability to run at higher sensitivity levels your machine might otherwise be able to do at a site. That's just my pet theory anyway. Others may differ...
