GP3000 Threshold Question

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Hi everyone, I'm new to the forums. I just bought a used GP3000 and it seems to work fine (I took it out to some bad ground and did some testing with small pieces of lead) but the threshold I'm not sure about. At the lowest level it never goes silent, as I slowly increase it, it gets to a point where it seems to get loud all at once, and louder yet the further I turn it up. When turning it up and I hit the spot where it starts to make an audible difference, the threshold is warbly sounding. Kinda sounds like it's under water. It won't stay steady until turn it up a little more. I know you should keep the threshold as quiet as possible while still being easily able to hear it but as you turn it down, you get to the warbly part and then it's inaudible all at once except for a hum that appears to me to be nothing more than like the hum from a stereo with the volume all the way down; just the sound of current moving through it's innards. In a nutshell, I would easily be able to hear the threshold at lower volume than where it gets warbly. But if I try to, the sound falls off altogether. And I worry that with the threshold not being steady at low volume, I may miss something good. Or, if I turn it up to where it smooths out, I may miss something. My understanding is that the GP Extreme had a threshold problem but that it was fixed prior to the 3000. Or is what my threshold doing similar with others who have the GP3000?

I'm not new to detecting. In my arsenal I also have a 6000 XL PRO, and an MXT. I have done more coin hunting than gold detecting, but I have found small gold with my MXT. And plenty of bullets/birdshot at good depth. The areas I have hunted for gold have hotrocks (river channels and old hydraulic mines) and I figured the GP would get more depth than my MXT and ignore most of the rocks. while testing I only hit a couple rocks that sounded off on the GP and they were softball sized or bigger and on the surface. Other than that the machine seemed to stay pretty quiet. I know the areas I intend to hunt have not been thrashed, otherwise I wouldn't be finding .22 and larger bullets (ancient) with my MXT. Plus I found some small gold there already. :)

Thanks in advance to anyone who has some insight on the threshold of this machine. Any other tips or advice for this particular machine is also very welcome. I did a lot of reading here before buying the GP and reading the manual on it. I hope the it's not an issue where I have to send it off to be serviced. Maybe this is normal for this machine? I have no Idea. That's why I'm asking you guys. Anxiety

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Not all that sure I was doing it right when I had the 3000, but, I went with the lowest setting I could that was smooth. No volume control; used amp or headphones for that. :mellow:

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I am guessing you are using a booster and have the volume set way to high.

Try the detector set up with standard headphones and the threshold should be silent up to about the 12 o’clock position, there will then be a small section of instability before it levels out to a steady hum. The stead hum will increase in volume as you go past the 12 o’clock position.

You should be able to do this at home if you switch into cancel mode.

Hope this helps



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