Terminology:
Ground balance - balancing the machine to use the ground phase conductivity as the zero point conductivity reference from which any conductive targets will be detected.
Mineralization - the level of oxidized ferrous material in the soil (basically rust particles, typically magnetite - Fe3O4) in the soil which has a signficant impact on ground phase reading but is not the ONLY factor that determines ground phase.
Manual Ground Balance - In settings, under Ground Balance, pumping the coil and manually adjusting the ground balance number +/- to make ground feedback noise go away.
Auto Ground Balance - In settings, Under Ground Balance, pumping the coil while simultaneously holding down the accept/reject button and letting the machine choose the ground balance number
Tracking Ground Balance - In settings, Under Ground Balance, hit the accept/reject button once until the ground balance tracking symbol (sinusoidal waveform icon) appears on the screen - enables automatic ground balance adjustment on the fly while swinging the coil. Should only be used when there is enough ground mineralization or salinity fluctuations that the tracking algorithm can detect and latch onto.
Misconceptions:
"High Ground Balance numbers indicate high mineralization" - you cannot infer the level of mineralization from the displayed GB number. Mineralization does effect ground phase reading but so do other factors such as moisture content and salinity content. You need a separate mineralization (Fe3O4) meter to determine the level of soil mineralization. Unfortunately, the Equinox doesn't have one.
"Ground Balance at the beginning of my detecting session and I am all set." Not true for the Equinox because Ground Balance is a mode specific parameter, so if you ground balance for one mode and then switch modes, you should ground balance again for that new mode. Not you will likely get a different GB number for that mode on the same patch of ground because each mode's Multi IQ profile is unique and will result in a different "mode compatible" ground balance number.
"I NEED to ground balance every time I use the detector." Yes and No. For 80 to 90% of detecting situations, the Equinox can handle either the default ground balance settings or a non-optimal ground balance setting pretty well, so you don't have to ground balance. It makes sense to do it however, because it is a fairly quick and easy thing to do when you start out for your session. No need to get OCD about it and rebalance constantly unless you are noticing issues such as increased ground feedback noise an jumpy ferrous TID's (-8/-7 TIDs) on every swing or if you know with certainty that ground mineralization and salinity will cause significant swings in ground phase over the plot of ground you are detecting (then Tracking Ground Balance may be more convenient then constantly manually or auto ground balancing your detector).
Ground Balance is a mode specific "local" setting which means that each mode uses a separate default GB setting and if you choose to optimize GB, each mode needs to be separately ground balanced. This is because the ground balance setting is based on the Multi IQ profile which is unique for each mode. Without going into a lot of technical mumbo jumbo (primarily because the details are ML proprietary and kept from us end users and secondarily because I probably wouldn't understand it even if I knew the details) it is apparent based on how the machine behaves and that Mult IQ facilitates the ability to work pretty well with the default value provided the soil is "mild" or typical of most detecting areas. Therefore, Equinox will work fine within probably 20 points of the default setting under 80 to 90% of soil conditions. However, Multi IQ's use of multiple frequencies ALSO allows you to dial in a really good ground balance should you choose to either manually adjust ground balance or "AUTO" ground balance by pumping the coil and letting the Equinox select the optimal ground balance setting. Multi IQ also really shines under salt beach conditions and combined salt beach - black sand conditions because the multiple frequencies allow the Equinox to do a multi-point calibration of ground phase that accounts for the salinity conductivity effects and the magnetic effects of ferrous mineralization (black sand).
In summary, under most conditions you can get away with the default ground balance settings. If, when in ALL METAL (depressed horseshoe button) and you are hearing a lot of ferrous ground feedback and negative 8, negative 7 bouncing TIDs, then it is wise to do a manual or auto ground balance to clean things up. If you have moderately mineralized soil and/or highly fluctuating ground phase (typically due to mineralization or salinity effects) then tracking ground balance works well. It automatically tracks changes in mineralization/salinity and periodically rebalances the machine on the fly. Don't be afraid to use tracking ground balance when needed, it does not appear to have any detrimental effects. But I would avoid using tracking ground balance if your soil is really mild or you are on a dry beach because then there is not enough mineralization or salinity for the ground balance tracking algorithm to grab onto.
HTH
