When does GB not matter?

[michaelosully]

I am usually able to Ground Balance my 305 without difficulty, usually with a setting in the midrange (6 to 12 or so). However, there is an area I hunt that when adjusting my GB in either direction (more positive or more negative) that just does not make any difference in the GB tone. I can go from GB of '0' to GB of '20' without any change in the tone (the tone is there but it does not change). I go to All Metal and checked for any targets before GB'ing. I have tried varying my sensitivity when this happens (from 1 to 10 and every setting in between) then adjusting GB and it still makes no difference in the GB tone. I have tried it with both my coils (standard and a 6"dd HF) to see if that would make a difference but still the same. Tried turning off/on the detector, no difference. Changed noise cancel, no difference. When this happens, I usually do a factory reset, check my NC, adjust my sensitivity up until it begins to chatter, then back off slightly, and then start detecting. So basically I am just reverting to using factory default GB when hunting in this area.

Questions:
If there is no mineralization in the ground...does GB not matter? Just set GB to 20 and start detecting?
If there is no change in the tone (from low to high or vice-versa) does it mean I am in an area with absolutely no mineralization, mineralized ground but neutral (is this even possible???), or something else?
Would a negative GB setting (positive # like 18 to 20) or a positive GB setting (1 to 3) make any difference as to depth when this happens? Or does GB ever affect depth?

Not sure what it means when the GB tone won't change and I know I'm overthinking this but I am perplexed (easy to do at my age). I know I am supposed to listen to what my detector is telling me so would someone please explain what is going on.
Help please!

 

[Digger]

If increasing your ground phase number has no affect on the audio tone, then you are likely passed the "perfect" ground balance setting. And if you are raising the ground phase number at this point, you are setting the ground phase to a more positive setting than what a "perfect" setting might warrant. However, with the information you have provided, I would speculate that the soil you are detecting is very moderately mineralized. So frankly, any setting you chose should produce good results. A larger than necessary ground balance number only means that your over-compensating for mineralization that may or may not exist. If running with that setting doesn't cause undue chatter, then go for it. Personally, I prefer to run with a slightly positive ground balance. Seems to make the detector think the ground is "hotter" than it actually is. And in my mind, I get a bit more depth and an increase in sensitivity. JMHO HH Randy

 

[fwcrawford]

I have noticed this also when trying to ground balance my X-Terra 50 at some locations.
What I am getting when I switch to ground balance mode is a "wavering" tone and it does not change when adjusting the ground balance from one extreme to the other.
I usually set it at the factory default which is 6 and start detecting... does not seem to have any negative effects from what I have seen while searching.. I have noticed that this seems to happen more when I have over red clay type soil sites.
Perhaps this is the moderately mineralized soil Digger is referring to.

 

[teviotlad]

ive posted on this before with my xterra 305. on the beach it doesnt matter what gb setting the tone doesnt change at all. however u need to be careful as i did some tests on wet sand with different gb settings. i found the higher the setting, the greater the depth, so i always use gb at 20 on beach or wet sand. it made a lot of difference to depth, from say a mid point setting of 10. id be interested if someone else could try this on the 305 to confirm my findings.

 

[michaelosully]

Thank you all very much for the input. I am glad to know that others have experienced this with their 305. Guess I still do not understand why there would be no change in tone at all when either raising or lowering the GB but it sounds like I should go with a lower setting (more positive) to get the best performance when this happens since setting doesn't seem to matter.

Thanks to fwcrawford and teviotlad for sharing . I have gone back thru some of your past posts to try and learn more about whats going on when this happens.

Randy, thanks for letting me know that if "over-compensating" GB doesn't cause undue chatter, then I am OK to go. Next time this happens, I will try lowering my GB setting to Zero and then raise it incrementally to see if I can get any chatter at all. My recollection is that when this happens, even at a high sensitivity setting (9 or 10) I get no chatter. Also wanted to let you know that my wife often tells me that I'm "well 'passed the perfect setting' so dial it back a little". What's an old guy to do?

 

[Digger]

would be your Threshold setting. If it is set too high, it will be difficult to hear much variance in the GB tones. Try lowering the Threshold to a level where you can just barely hear it with the volume at full bore. Then back it off a click! HH Randy

 

[Big Boys Hobbies]

If increasing your ground phase number has no affect on the audio tone, then you are likely passed the "perfect" ground balance setting. And if you are raising the ground phase number at this point, you are setting the ground phase to a more positive setting than what a "perfect" setting might warrant. However, with the information you have provided, I would speculate that the soil you are detecting is very moderately mineralized. So frankly, any setting you chose should produce good results. A larger than necessary ground balance number only means that your over-compensating for mineralization that may or may not exist. If running with that setting doesn't cause undue chatter, then go for it. Personally, I prefer to run with a slightly positive ground balance. Seems to make the detector think the ground is "hotter" than it actually is. And in my mind, I get a bit more depth and an increase in sensitivity. JMHO HH Randy

Great post Randy!!

 

[michaelosully]

Thanks again for all the feedback and to provide an update:

I tried out all the suggestions at this particular site where this happens and found that if I lower my threshold to zero or in the negative range then raise my GB setting, I get the sense that I may be about to reach a change in the GB tone...but don't quite get there. Oh well, I still find targets to dig at this site and the older I get, the shallower I want to dig.

 

[jreb]

Never