The iSAT function was first implemented in the Gold Racer, even tho the FG+ came out first. It took some time to get right on the 56khz Gold Racer, Just remember, its primarily used for the return of the threshold when working nasty ground in AM....and it will effect depth and sensitivity of a target. Over compensating the threshold on the VLF will cost you depth. In other words...keep the thresh low, just like that of a PI machine. Same principle....if the target does not reach the floor of the threshold due to the thresh being too high, you lose it.
The gain settings on most Nokta/Makro models is set rather high for our soils, and not all models implement the gain vs the target amplification using the same sequence. As an example....the gain can bet set from 1-5...thats the gain...the numbers you see changing from 1-5 is the amplification...the gain is set to a max of 5 in that set...some models have a much bigger set...for instance 1-40 ect ect.
This gives you an idea of how to set your gain levels without going over board....you can normally tell where these levels are set, by winding the gain up from 1 to max, and listening for a slight pause between each number...when you hear the pause..this will tell you, you have reached the next gain level.
A special note when working high mineralization that is saturated/wet. Lower your gain if the detector goes into overload...some times just a few clicks lower will suffice....other times a much lower figure is required....dont panic to much as these detectors a very high gained. I often use mine on very low gain levels....this helps with IDing targets close together in Disc modes. The AM side of these models gives target ID as well, but unlike the Disc side of them, it registers a number much faster, and at a much less signal strength. The Disc side of these models takes away some of the thinking by not registering a target ID due to the signal strength, if its not able to lock on...it wont show...leaving only the tone for your to think about...and most of us will dig a high tone.
Sometimes the Auto GB operation is a little generous, meaning you will hear the ready BEEP a little early, but if you listen carefully, you may hear that the GB is still a tad out as your raise and lower the coil...use your manual controls for a much finer GB.
Gain levels.
Gold Racer 0-29 / 30 -39 / 40-49 / 50-59 / 60-69 / 70-79 / 80-89/ 90-99
Fors Gold + - 0-54 / 55-99
Fors Gold / Core - 0-49 / 50-99
These settings may have changed during the release of latter models of the same model....however, the pause should let you know.?