Chasing Stupidly Small Gold Continued And A Dramatic Rescue

[Walker]

Hey friends, I might still have some really good footage of my friends and I pulling a kangaroo out of a shaft in 2006 . It was just north of laverton. I was detecting and I heard a ruckus in a shaft. I saw the roo so I went back to camp and got my Australian friend Steve. He made a lasso and pulled it out. It was quite an experience. The video I have is low quality but if I can get it to work and post it,  it’s worth seeing. Thanks for the post, it brought back some lost memories. Hope you all are doing well.

[Gold Catcher]

On 4/3/2020 at 12:32 PM, Jonathan Porter said:

How close you can get the coil to the ground is determined by how much saturation signal is present.

Hi Jp, can you recommend settings for grounds that are plagued by high ground saturation? I usually reduce gain until the coil pumping keeps the threshold stable right above ground, but at times this means sensitivity of 6 or lower in HY/normal with the ML14 coil. Any other settings/tactics that can be beneficial without too much impacting performance? Thanks!

[Gold Catcher]

To add, I can of course go to general/normal or HY/difficult, but was wondering if there is anything else that might help. Thanks.

[Norvic]

Re. scrubbing the ground with the coil, the best coil protector for doing such I have found by far, is a self made one that Phoenix posted about a few years back, you simply cut a coil size piece of PC 0.8 to 1mm thick sheet plus about 5mm all-round oversize, rough it up real well and adhere it to bottom of coil with silastic adhesive or similar. Light as and whilst 1mm thick doesn`t sound thick enough it is ample and will outlast multiple manufactured covers. In OZ can obtain rolled up sheets of PC in hardware stores.

Ensure you get PC ie  PolyCarbonate sheet not Perspex and as you need get good adhesion of adhesive, rough it up properly, I simply use coarse sandpaper on an orbital sander. No more taking cover off to remove dirt so ensure you get the adhesive sealing completely around edge. Tis the stuff fighter jet canopies are made of.

A top project for times like this.

[flakmagnet]

With the 5000 I pumped the coil after every loud-ish sound whether it was a signal, a hot rock or a false…ground balance is everything.

 

[PeterInSa]

Kw, Thanks for the Vid Clearing the Ground.

Would have liked to hear see the results of some of those very very faints signals.

Re Clearing the ground in Vic Triangle, ditto have done the same with open ground and diggings, putting back stones/tree limbs and leaf litter afterwards, because its the thing to do and doesn't give the Greenies a chance to complain.

Peter

[Jonathan Porter]

On 4/6/2020 at 11:51 AM, Gold Catcher said:

Hi Jp, can you recommend settings for grounds that are plagued by high ground saturation? I usually reduce gain until the coil pumping keeps the threshold stable right above ground, but at times this means sensitivity of 6 or lower in HY/normal with the ML14 coil. Any other settings/tactics that can be beneficial without too much impacting performance? Thanks!

The mode that Saturates the most is High Yield Normal, it is by far the most powerful deep punching mode on the GPZ 7000 even on larger targets but only in the Normal mode and only if the mineralisation levels allow. Using the Sensitivity to regulate Saturation will work to some degree but of course there is going to be a trade off on performance on target signals too.

As previously mentioned there are a number of ways to control Saturation signals, one is to lift the coil and GB above the Saturation point and then try to sweep the coil in that zone, this is hard to do when wanting to have good coil control but with practice becomes second nature after a while. In a lot of cases the GPZ saturates less than other detectors thanks to the DOD design coils, however when they do Saturate it is a lot more obvious thanks to ZVT.

At the end of the day it’s a balancing act for the areas you are detecting in, the vast majority of places I detect I have no choice and HAVE to detect in Difficult because the mineralisation levels negate the advantage of Normal due to all the variation. The things I look to are firstly testing a target in the chosen ground and see which mode provides the best response, sometimes it will surprise how well HY/Diff does on the smaller pieces. To do this properly you need to move about the target over a reasonable area to get an idea of the localised ground signal response, just changing modes and waving over the target isn’t the right approach, you have to be honest with yourself ”would you have hit the target walking about blind relative to local ground signal?” 

If the ground can handle Normal then I look to adjusting the Target Volume as a means of ironing out the variations in the Threshold in conjunction I will also adjust the sensitivity but only when I‘m happy with the over-all volume of the machine relative to threshold behaviour. As an example I find myself sometimes working ground that is giving near zero feedback in Difficult even with Volume on 10 and Sensitivity pushed out to 12, in this instance I could easily revert to Normal but when I do so the ground variation is still a bit much for the Normal mode so, I pull back the sensitivity and the volume till the audio variations sound equal to Difficult mode.

The other thing I do is adjust my mental approach because now the detector is reacting to a lot more information and producing a louder signal response on targets, this means I have to mentally filter out a lot more. A more aggressive signal investigation approach till you find a few pieces and familiarise yourself with detector behaviour will help, this can take an hour or so as your brain adjusts. I tend to only dig good sounding targets and mentally ear-mark the iffy responses to avoid the negativity of constant ground noise digs until I’m more confident, the good targets aren’t going anywhere!

There is a lot of ground out there that can be worked with both Normal and Difficult Modes, the GPZ runs surprising quiet even in noisy ground types from a movement signal point of view, however Normal reacts a lot more aggressively to target like variations. For those of you who have the luxury of working in Normal all the time, you actually have an even bigger mental adjustment to make if you NEED to go to Difficult mode, you will feel deaf like the detector has died due to lack of feedback from the ground. For Difficult I suggest you increase your Normal Mode sensitivity by at least two points above and even lift the Target Volume a couple of points to help compensate. Remember the reason you’ve gone to Difficult is because of all the ground variation and false signals created in Normal. The Threshold will however sound a bit busy (Bitchy) and can take a bit of getting used to, sometimes going a point or two up on your threshold can help with this, the busyness is caused by the natural elevated Gain levels of the Difficult modes. Range of Motion and subtle threshold pitch variations become far more important in Difficult, but when you get the combination right the targets really stand out loud and clear on the GPZ.

Youtube Video:
The area in the video looks like typical WA ground and although mineralised is pretty homogeneous from a GB point of view, I would not consider that ground to be too Saturable even with the more modern Flat wound mono’s. The coil used is a NF Advantage elliptical mono a very popular coil in its day for WA thanks to good sensitivity to small gold near the surface and excellent coverage when looking for patches, but no where near as sensitive to small gold as a Flat wound Mono coil and also way less Saturation signal. Interesting to see the recently reclaimed cut line to the side of his raked areas, seems there had a been a drilling program in the area at some stage.

JP

[Gold Catcher]

On 4/7/2020 at 1:18 PM, Jonathan Porter said:

As previously mentioned there are a number of ways to control Saturation signals,

Thanks for your detailed answer, JP! This is super helpful! Much appreciated, as always. ?

[flakmagnet]

8 hours ago, kiwijw said:

You can probably imagine how very faint it was when he first got a hint of it being there before scraping away the rocks.

I agree, but the first swing in the video is a definite 'dig me' sound no question about it. That said, he certainly earned that gorgeous nugget.