John-Edmonton said:
It is well balanced to the piece of ground underneath the coil. Five feet away, conditions could be different?
Most of the relic machines I have used have some sort of ground mineralization readout on the meter so that you can do another GB if needed. However if if the machine doesn't have a meter or a readout on its meter, any experienced relic hunter can easily tell if the GB has shifted as the machine thresh hold will start making noise if you lift or move the coil closer to the ground because if it is out of balance the machine will start reacting to signal from the ground. Other machines have ground tracking that you can turn on or off as needed and usually some sort of track inhibit or user adjustable track speed so that the auto tracking won't tune out a target.
Having a fixed ground balance is not a good thing for a dedicated relic machine. However while the fixed GB is a disadvantage it is not the most important feature when determining whether or not this will be a competitive relic machine with those from other manufacturers. The most important feature is one I haven't seen any info about yet.
That feature is how the audio system of the machine works. My experience with Garrett machines (a Gti-1500 and a GTAX-550) is that the audio system doesn't cut it for relics. A good relic machine will offer a good tone ID system that is based on continuous not sampled audio. What I mean by this is that it seems to me that the way those Garrett machine's audio works is that the processor looks at the signal from the coil and then samples it at peak signal strength, classifies the target and then
synthesizes the audio tone it plays based on its ID of the target. A good relic machine will send the audio from the target in a continuous stream so that the operator can hear the audio signal at all times, particularly how the target audio rises and falls as the coil approaches, passes over and then leaves the target. Perhaps this is easier to explain by use of a recent example from one of my detecting trips. I was using a Tek T2 (a fine relic machine) in 2+ audio mode. The farm field I was hunting was right next to a public camp ground and there were a fair number of pulltabs (for a farm field) in the ground. They were coming up at 42 or 43 on the target ID meter. After I had dug up a half dozen or so I started ignoring targets that sounded like pulltabs and showed up with a TID or 42 or 43. After a few hours of detecting I came across a target that came up as a solid, repeatable 42 but it sounded completely different. The second I heard the audio I said to myself I don't know what this target is but it isn't a pulltab. It turned out to be an old crusty indian head cent which after cleaning revealed itself to be a 1868. The same thing goes for some iron targets, nails sound one way but ox shoes sound a different way even though they both play an iron grunt. The GTI-1500 would have synthesized the same sound for each of those pairs of targets, though the target imaging would have let you see the different size of the ox shoe compared to the nail (in most cases).
I have to say, that as a dedicated relic hunter who seldom if ever does any other type of detecting, that after reviewing the info on the Garrett website I am a bit underwhelmed - the frequency seems a bit low for a relic machine (most of the relic machines run at 12 or 13 khz), the target ID resolution seems low (for example the Tek T2 has 40 tid numbers for iron alone and another 60 for the rest of the target spectrum), no manual GB, and most importantly I bet the audio system falls short as described above.
I hope the as of yet unannounced machine that Uncle Willy and others have hinted at seems more competitive with other relic machines than the Ace 350 seems to be. However I guess the real proof will be in the hunting, I can't wait until the next team based, relic shoot out to see if Garrett can get out of last place for a change.