interesting so the f70 sl mode is not the same as the 75bp? i almost bought the f70 once but u cant choose the gb number manually so i opted to not get it .
With the F75 you can choose the gb number manually if you want...
I usually don't have any inclination to GB at any numbers that aren't optimum for the soil I am hunting in although I do know others have their reasons to do that.
My F70 and the auto GB feature seems to do fine for me so far.
In good soil I got massive depth easily up to 12" and further, in my present very bad soil areas my audio will match those depths but the screen info only shows targets down to about 7" which matches or beats most detectors I have heard of around here.
That being said there is a way to fool the F70 to balance to other numbers which is simply by GB'ing over objects with different continuity readings.
Gather up a collection of different ones and I suppose you could almost pick your numbers if that is what you want to do.
I have read about a technique that supposedly works pretty well using the F75 on a saltwater beach but you need to get the GB numbers under 10.
No way can I come close to that number with my F70 normally but I happen to have a hot rock of some kind I found the other day that I discovered will let me GB below 10 if I swing over this thing as I set it.
Next vacation I take to Gulf Shores the F70 comes with me but so will that rock.
I think the high gain on the f75 that Larry is speaking of is what causes the loss of depth in my "red clay" areas. Kinda like the high beams in the fog.....but its not a true depth loss...the f75 will still sound off but in the bad stuff it just becomes very hard to tell a bullet from a nail at depth. This is were "In my area" the AT gold seems to out perform the f75 or atleast for me it was easier to tell good targets from bad. But dont get me wrong; I still think the f75 is one of the best machines I have used.
High beams in fog...excellent way to put the experience of hunting in severe red clay, iron infested and infused mineralized soil like I have in many areas around here.
Despite that, and despite the fact that when you get deeper to the 6-7" range where I can get screen info the ID's are anything but solid and stable, there is still behavior and indications that I have noticed that have prompted me to dig that deep and find good targets at those depths way more often than trash.
Just another language I have to learn as far as I am concerned and I am doing pretty good at learning it...so far.
Beyond that it is all about only the audio, even in all metal, and that is something I will have to work on next.
From what I can tell in this area my F70 seems to do as well, (for me), if not better than all of the VLF detectors used by any other hunter around here I have ever hunted with, talked to or heard of.
Hunting mostly public parks as I do I prefer to use units with some sort of discrimination because digging every signal I come across both deep and shallow is just no longer an option for me.
One day a TDI might join my arsenal so I am studying up on ways that it might be possible to use that thing to find deeper silver and nickels again without digging absolutely everything in sight.
Keith Southern and a few others have posted ways that might work.
For now if I can get to the 4-7" area in the worst of this devil dirt there seems to be a pretty good amount of missed targets at those levels so the PI is on the back burner for now.
