Hi Randy, how are things.
I was so glad they gave us back full control with the ground balance offset. Probably the best feature on the 705's I think.
I was pleased with the balance on the 305's factory pre-set too, very close to 30's pre-set, probably with an edge to the 30 being on the positive side, but both machines act very differently with the 305's new armoury. I have to admit it came as a bit of a shock to find out the detector was so more advanced than the 30's. I had to quickly fall back on the Teardrop Principal after taking it to my usual haunts thinking I could just walk on from where I left off a few days earlier.
I think the ground balancing behavior of particular detectors has always thrown people off over the years. It may have been a mixture of detectors with rather sloppy manual balance that would drift all over the place, a lack of pragmatic explanation in detector manual's, and the continuation of producing pre-set only ground balance units. I'm not too sure. But as we know, it's really one of the easiest of settings to master, and the most important.
My way of explaining it, while theoreticaly skew wiff, may make a bit of pragmatic sense. I hope it does anyway.
On an air-test (one of the worst things we can do with a detector), both above and below the coil, a coin will hit at the same distance. The frequency gets kicked out into the air then becomes 'fluffy'. Regardless of where the ground balance setting is.
By placing the coil on the ground, the frequency that's going downwards, is held together by the ground. Above the coil it virtually remains the same, there's nothing to keep holding it in, so it still gets out to escape and move around.
But when we start to run the ground balance positive by increasing the - pad, we put more of the frequency's power downward, asking the XTerra to see and interpret more. Fooling it just like you say Randy, and making it work for us like a machine should, and not letting it dictate the terms to us.
With the unit running positive balance, we need to help it by giving it as much + sensitivity to use as we can, while remaining stable enough to correctly make ID tones.
We want those deep on-edge coin signals to come through with more certainty about them, instead of them coming through as deep triple-hits, changing tones or iron hits.
When we would work very hardpacked ground that a coin simply can't work it's way down through, and can't even get on-edge because the density of the ground keeps leveling it out so in the end they just give up and lay flat, we would throw the ground balance on to the negative side with the + pad, dropping sensitivity along with it, so it makes an even match going into the ground.
The reason being, we only want to hear and cherry pick those good signals down to four inches max, and do not want nor need to hear deeper targets, iron falseing, or any ground-noise feedback to annoy us. Only leaving us to make distinction between good hits and junk at the depths we have chosen to detect to.
Along the way, checking the odd target in both cases, for slight improvements we can make to signals and making sure we are getting either a very deep or very shallow depth.
And that's where The Teardrop Principle comes in.
I still do it at least twice a week, mainly in new trashy spots I'm not used to yet. When I need to both hear and see the level of all targets, both ferrous and non-ferrous, to gain a small understanding of where the tones will be taking me, and at which depth the ground matrix holds them, and why I always run in tones so I'm not notching out or losing depth over the on-edge coins. As well as running the most beneficial balance I can before the ground changes on me.
I meant to start taking pictures today, as the on-ground and dug-ground pics will make it easier to explain things, but I've been so caught up in an area that I ran out of time, so it'll be a day or two before I can post the thread up.
Every little bit helps, so I'm expecting everyone to post their procedures directly on to the thread too. No one gets out of here alive!
I just hope I can write it as well as you do Randy.
