Hi Grumpy
I have been reading your above inquiries with interest and felt prompted to write this message to you.
I am a proud Sovereign GT owner myself and I would like to say that "I too" have experienced the numbers on the meter jumping around and I now believe that this is often down to a few good reasons which I will explain below.
Many objects lay at different angles in the ground and in differing mineralization conditions and when the GT coil is passed over an object over and over again, it gives the computer chips in the control box a series of differing signals which causes those chips to give out a series of different readings from the 17 frequencies that the detector is detecting in, what I am talking about here, is the Broad Band Spectrum of frequencies that the Sovereign GT uses to detect with.
The constantly changing input from every sweep over an object results in new processed data arriving at the meter from the computer chips in the detectors control box.
Those differing signals will be translated into varying numbers on the meter and I think that this is what you have been experiencing from your Sovereign GT and what you have need of an answer too.
What I have briefly explained above, is one of the several reasons for why the Sovereign GT coil should be slow swept over the ground by its operator, as slow sweeping will give the detectors computer chips and filter chips the time they require to receive and process the information that they are geared to process.
There can be little doubt, that people who have bought the Sovereign GT have become confused over this matter, as they have been used to using other detectors that sometimes do not have the chip technology that can be found within the Sovereign GT.
It is also essential when using the Sovereign GT to give it a warm up period after switch on, this is so that its chips can set themselves properly and so that they can make themselves ready for the complex challenges that the ground your going to search, will chuck at them.
I have found that it is also essential and important to switch the detector on with the coil held up off the ground for about half a minute before returning the coil back to the ground, as this helps settle the machine down in readiness for processing ground data.
The the operator should then sweep the coil of the GT over the ground in a slow wide sweep several times before you set off searching in order that the GT has time to get used to and to filter out the mineralization of the ground in which you'll be searching.
So important to remember is; If the Sovereigns GT's detector chips are not given the right amount of time to settle and to filter and process the information that it needs too from the ground before you set off, the detector will not be able to set itself up properly and will probably respond for a short while in a fashion that will reflect that in the meter readings and its behavior.
Its a bit like waking you up suddenly from a deep sleep and expecting you to be spot on in what you do from start - lol
As most will now be aware, the Minelab Sovereign GT is a high technology detector and it is extremely good at processing and evaluating signals picked up by it's BBS frequency search system.
Also remember that the GT detector is constantly receiving 17 differing signals from the ground and the metals and conductive objects in it, so don't be surprised that when the numbers change or are erratic at times - even when sweeping over the same object.
The angle the object is in the ground, its size and its conductivity level, are just some of the many things that the Sovereign GT's chips have to quickly process and work out.
Couple that with having to process 17 differing frequencies at the same time and having to filter the rubbish out of all of those signals and you will appreciate how much the Sovereign GT has to do in a short period of time in order to alert you to a good find.
The Sovereign GT is a fantastic all round machine and you will by now appreciate that it'll take time for you to learn how it reacts to different situations and different metal objects, but if your serious about metal detecting Grumpy - "that's the fun of it all".
So please consider this, if you give the Sovereign GT the time it needs to achieve all of the above, you'll be surprised what it gives you in return and how it finds the good finds, time after time.
I hope that this message has helped you in some way and don't let it put you off, I also hope this message and you will go on to help others too, and as all good metal detectorist's say; - "IF IN DOUBT" - "DIG IT OUT".
If the meter confuses you, then just take it off and use a pair of amplified headphones as you will find just as much without the use of meter, I can assure you that this is true as the Sovereign has a good tone ID spectrum.
All the very best to you Grumpy and to everyone on this site - Happy Hunting guys, for if you own a Sovereign GT, you will have happy hunting indeed, as it's a leader amongst all round detectors.
Dave Tee
Plymouth
Devon
UK :0)