How To Better Use The Sensitivity Setting On A GPZ 7000

[Jonathan Porter]

Normal is a Ground type mode whereas General is a Gold mode, so you can use General in Normal or Difficult dependent on ground conditions.

JP

[whitebutler]

JP,

How is the high yield with difficult? I haven't had much luck jumping over to the general in normal. Nor have I had luck in high yield in difficult. Now high yield normal is so damn hot. I've found 95% of my gold there. With the sensetivity at 14. B and Z at three and a half. And using killer bee headphones.

[flakmagnet]

More terrific food for thought.

Thank you Jasong, Norvic, JP et al.

The sum of these comments is very helpful and great fun to read.

[Jonathan Porter]

18 hours ago, whitebutler said:

JP,

How is the high yield with difficult? I haven't had much luck jumping over to the general in normal. Nor have I had luck in high yield in difficult. Now high yield normal is so damn hot. I've found 95% of my gold there. With the sensetivity at 14. B and Z at three and a half. And using killer bee headphones.

High Yield and General/Xtra Deep are like a multi frequency VLF, High Yield is the equivalent to say a 70 Khz Gold Bug II, whereas General is more like the 32 Khz XT 17000. I give these examples to put things into perspective when your chasing a range of target sizes. Most people will do best in High Yield just like the GB II outdoes almost every VLF machine on the small gold thanks to its high freq. 

However when you add the ability to use Normal Ground Type modes the lines get blurred, in all my testing High Yield Normal has provided the MAX depth on any target so long as the ground allows its use. General is better on solid sluggy nuggets at depth with a BIG reduction in ground signal especially the near to coil responses such as saturation but also salt and general mineralisation signals.

When in Difficult mode the differences on target sizes becomes more obvious, High Yield Difficult is very good on any type of nugget up to around 10 grams, if the gold is rough or prickly or specimen-like then the actual weight of the gold doesn't really have much say in the response, it is then down to  the "Time Constant" of the target. The differences I suppose are very similar to Fine Gold and Enhance on the 5000.

The key is to come to terms with the type of gold you are seeking and the possible depth range of that gold, I have had considerable success in noisy variable ground chasing solid nuggets over 12 grams using the General/Difficult modes taking full advantage of the better signal response given on sluggy heavy gold. 

There is however a "Hole" in the timings of Normal modes where a half ounce nugget will respond better in Difficult compared to Normal, this was also evident on the GPX 5000 and we actually caught it on film when Steve was visiting with me here in Australia. I'm not sure how evident this hole is in some ground types as differing ground types moves the GB null around quite a lot so it might only be in certain areas.

JP

[whitebutler]

Thank you JP. Great explanation with examples. You really help to fill in the blanks where the manuals don't give examples. It makes me a better detectorist. Thank you for your time. 

John

[spinifex]

14 hours ago, kiwijw said:

I cant say or add anything more to that lot...... except....... that I have found that less is more. 

I agree JW

its like a great pizza, I would rather have two pizza's,thin with less topping than one, thick with heaps of topping and soggy. 

I would rather spend the day with just enough information for my brain to process efficiently that being bombarded with too much.

thanks everyone for this great discussion.

Pete

 

[Rye Patch Ron]

On 1/19/2017 at 10:04 AM, Steve Herschbach said:

More importantly, neither of us would ever advocate just using some settings gleaned off the internet as anything more than a starting point for your own experimentation, to find what works best for you in given locations depending on your own detecting style and preferences. Using some setting off the internet is like buying a car and then getting on the internet and asking which gear setting and throttle setting combination is best. It all depends on the road and the driver.

You absolutely correct Steve. Most people just want the magic settings when there is only start here and fix it to conditions.

 

[DigsAlot]

On 1/19/2017 at 10:04 AM, Steve Herschbach said:

There are two types of Gain or Sensitivity settings. One type boosts the actual transmit (TX) power of the detector. The other type boosts or amplifies the receive (RX) signal. The GPZ 7000 Sensitivity setting is the second type. That being the case increasing the sensitivity is not actually making the machine more powerful. You amplify signals from nuggets, but also from ground noise and electrical interference (EMI).

etc.....snip (see post)

Perfectly stated post. I got more from this post than I have from most others about settings.