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How To Better Use The Sensitivity Setting On A GPZ 7000


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found Flak;

if I knew all the great stuff Steve and JP know...first, I would be smart and second I would have written that wonderful explanation Steve just wrote!

I will be adding this to my notebook.

And finally, I used doc's settings, norms setting, lunks settings, Jonathan Porter's (80% of the time). The only settings I could not tolerate is Steve's-they really are insane setting!

What ever works, it is a big universe!

and factory default...I have found bits of gold with them all.

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 I think the biggest bang you can get from the 7 is running in Normal ground setting verses Difficult, if the soil allows.

The other settings seem to have minimal effect compared to that option, and you can run almost anything and still find gold.

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Wow.

Great input all of you.

Steve you must be trapped indoors or have had too much coffee or both,

but whatever it may have been, thank you for taking the time to describe in a usable way

what for many is indescribable. 

Wes I really agree with your comment about Normal vs Difficult too.

I am comfortable running the 7000, and, like Steve, I use what I call ragged settings, but I have never had a clear picture of how Sensitivity meshes and works with the other settings either with the GPX 5000 or the 7000.  

I knew I would get not only more clarity but more opinions if I put the question to you all - so thank you everyone for both.

It's why I pay attention to this forum.

(now back to experimenting with the tuning on what is turning out to be

the best detector I have ever used)

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So true, what ever works for you.  I have tried Steve's and JP's and others I know that swing 7s but I have yet to find what I like. Seems all the soil and rocks and add water (lately more than not) and wind on wet grass and a helicopter flying over all changes. I've also found bits and really big chunks all over the board at all different depths. 

I don't have an answer, but I know the best thing to do. Turn it on and swing it. That always get me something. 

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Wow!  Such a sensitive subject.  We can't seem to get enough of it for fear we missed something.

None of us will get it all but with a good grid pattern and a couple of passes it may be time to go to another patch.  The last pass after most of the trash has been removed I'll push the sensitivity up if I'm still getting some pieces.  If you wander search a patch it could last for a longer time on all settings. (The search for the missed grid gold!)

Mitchel

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Sure is a sensitive subject, but has been about since day one when detectors started to be used to find gold. Do you run a noisy machine or a quiet one? Now I`ve run around with everything cranked up until the 19", so I`ll probably be proved to be wrong here again but I think overall ZVT is better set with as little as possible internal noises, especially keep volume down <8,(rather go with a external low noise booster). This is something persistent young fella (JP) taught this deaf stubborn old fella, although of course us oldies know young fellas are normally as wrong as.  But one thing for sure the user that believes he/she left nothing behind is only kidding themselves

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I'm a bit late to the thread, but I think of the metal detector like a automobile radio receiver. Say we are driving around and listening to a specific station, the radio station is transmitting at a set power output which doesn't change, but as you drive around there are parts of the environment that affect how you receive that radio signal. Luckily we are given settings that allow us to adjust to these changing environments. 

If we drive behind a big hill that radio signal is going to be weaker so we want to bump up the sensitivity so we can hear it better, this is the level of amplification the radio applies to the signal from the antenna (not be to be confused with volume). This is like if we are looking for deep nuggets or to hear faint signals.

But if there is a pirate radio station nearby on the same channel (aka noise) then bumping the sensitivity up is going to amplify the pirate radio station just as much as the station we are listening to. This is where audio smoothing (or the stabilizer) comes in. Sometimes as you drive behind trees, buildings, under power lines, etc you will hear another station come in over the one you are listening to. Audio smoothing will take those quick "zings" out. But if you up the sensitivity, then you again raise those "zings" above the level of the smoothing. 

The timings are a bit more complex, there isn't really a simple analogy. But you know how AM radio can be received halfway around the world and FM often dissapears 100 miles from town? Radio waves interact differently with matter as the frequency and characteristic of the wave changes. This is the idea behind timings (very simply put). 

Ok, so far these are all adjustments happening inside the radio, ie - between the antenna and the radio receiver electionics. But we also have a big volume knob on the radio too, and that adjusts the audio signal the radio produces. It's only audio though, adjusting volume settings won't give us any new information that wasn't already in the radio, it won't make a faint station clearer, it only makes the speakers louder or quieter. 

So one last thing, if I'm driving through the mountains in Wyoming and give my radio settings to someone on the suburbs of LA, they probably won't even hear their radio station at all. This is why sharing settings is really only helpful in the same or similar locations.

Dunno if I made it more complex or not, but I find that when thinking about how all the detector settings work together it's a helpful analogy. Good luck with the machine, hope you get some nice ones!

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Top analogy, have found with the Z the volume control is not quite like a volume control on the audio side of things such as with a radio receiver. It seems to do more then amplify audio, to illustrate this if you adjust it much over 8 to compensate for bad hearing, you introduce a lot of internal noises and in particular you increase the Zs potential to pick up EMI. But if you add a low noise booster to the WM12 with a volume control and keep the Z set at 8 or lower, you can have a high but stable signal volume, and get a nice even quiet threshold.

Now I`m probably really complicating this subject but I just feel that volume control turned much above 8 takes away more then it gives wheras increasing the sensitivity is more a ground based control, in quiet ground you can have the sensitivity up in Normal and really gain, but switch from difficult to normal first.

 Heh!!!! this is my take from my use and the posts in this thread really enforce settings are an individual thing. I just know the magic of the Z is it can be very easy to use and very productive such as in default or you can crank it and gain a bit more, but that cranking can complicate things. Tis up to the individual to decide if there is a bit more to be gained or are you actually losing? Crikey, I am suffering from Cabin Fever aka Mango Madness, gotta get the coil out over some ground but this rain is so welcome.

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My thoughts are always on what is the driving force behind the settings, in the case of the GPZ its ZVT and major advances in the electronics allowing us to now tap into the full noise floor potential of the new tech due to being able to use Audio Smoothing on OFF.

The rest is just down to local conditions and your individual ability to "pick out" a deep target signal from the general audio delivery of the detector. I always err on the conservative side because I am always working in highly variable mineralised soils so am forced to use Difficult. And what most people don't realise is Difficult is already insanely hot from a gain perspective because that is the nature of the timing and what is required under the hood to bring up a target responses when Difficult mode is used.

If you listen to the threshold of Difficult compared to Normal you can hear the extra Gain associated with the them, it takes about 10 minutes for your brain to adjust to the extra variable-ness of the threshold (slightly jittery threshold indicative of elevated Gain levels) when going from Difficult to Normal and back again.

JP

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I would like to say, I love ths forum and especially the topics on the ZED. I found early on with the 7K that the target responce in Normal was much better than in Difficult I am wondering if it is because I am hunting in very mild ground. I switched between Normal and Difficult on un dug targets. Does the Difficult setting only apply to hot ground?

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