Jp’s Audio Visual Gold Thread

[Gold Catcher]

11 hours ago, RedDirtDigger said:

Yep they do, mainly smaller nuggets 1-3 grams at a foot or so (a swap to high yield resulted in no or weak signal

Thanks for sharing, RDD. Another example of how HY/high gain settings can miss targets

[RedDirtDigger]

13 hours ago, Jonathan Porter said:

Hi RDD, Are you using Normal or Difficult? Extra deep samples much later than the other two Gold Modes so in Difficult there is a family large reduction in signal on fast time constant targets, this is gathered back somewhat in the Normal Ground Type mode. Also it would help if I knew how your setting up your GPZ settings wise and the method of listening to the audio.

JP

Im using mostly difficult, thres 27, sens 12-15, smooth off, ss300 phones straight from wm. ( steelphase put a hum in the phones so i not use for now). I use 19 coil when ground depth/gold finds prompt me.

Above seem to work well on very slow swing speed, happy for you to suggest better options for deeper targets on worked ground old patches

i have tried different settings but not enough over undug targets to work out what is superior.

RDD

[Jonathan Porter]

2 hours ago, RedDirtDigger said:

Im using mostly difficult, thres 27, sens 12-15, smooth off, ss300 phones straight from wm. ( steelphase put a hum in the phones so i not use for now). I use 19 coil when ground depth/gold finds prompt me.

Above seem to work well on very slow swing speed, happy for you to suggest better options for deeper targets on worked ground old patches

i have tried different settings but not enough over undug targets to work out what is superior.

RDD

Sorry to be a pain, but what is your Volume set to on the bottom right of the Detect page?

JP

[RedDirtDigger]

1 hour ago, Jonathan Porter said:

Sorry to be a pain, but what is your Volume set to on the bottom right of the Detect page?

JP

Vol is 7 or 8. GB auto, going to manual via user if getting gold and happy with detector stability. The main spots i detect have complex vertical dipping bedrock that changes beds every 50 metres with lots of iron rich volcanics and shales. I try detect along strikes to lessen my ground variation.

[Jonathan Porter]

Extra Deep is a later sampling timing that has good depth on slow time constant targets. The advantage of the Gold Mode is it’s very effective at removing a LOT of Salt signal and also near to surface ground signal response (both variability and Saturation signals), as such even though the target signal can be reduced a lot compared to other modes the actual deep target signal can stand out from the threshold enough to be recognisable. 

In effect you are doing a similar thing to using the Motion filter (Audio Smoothing) but in a more refined way because the timing is complete across the target size spectrum relative to what makes it through the delay. 

The other advantage of using Extra Deep is it has VERY good immunity to microphonic’s when the coil is rolled across hard pebbles and comes into contact with woody sticks, you’d be amazed how much information is lost due to variability in the threshold because of this effect especially in General Difficult. In the Normal modes it’s not noticed so much because the timing is more agressive and agile so the variability in the threshold masks the signals.

IMHO the ground Tracking is better in Extra deep than it is in General, there is way less up and down signal in High Yield and Extra deep compared to General, noise from coil raising and lowering has a really big impact on subtle target signals in the General mode especially in Difficult. 

Finally the range of motion of the coil is extremely important when chasing deep signals especially the ones that barely make it through the delay, it would pay to not sweep over a suspect target too often in any sort of tracking because the resultant remainder Eddie current after the delay will be right on the edge of detection. Interestingly I find the target response of some gold does not always get determined by how much actual weight of gold is present but is more to do with surface area relative to depth, getting the combination right can bring a surprising amount of gold to light, just be aware there will be some targets that are lost to the late sampling.

JP 

[mn90403]

JP,

I can read what you say and believe what you say but I can also see that it would be a hard concept for me actually hear.

Of course to the trained ear these concepts and descriptions have meaningful responses associated with concepts.  I would liken it to bird watching.  If your ears are good and you hear a sound or a bird you have never seen then you are without a clue until you see it or see a dead one or someone else shows you or teaches you.

I'd have to take a chance on setting the Zed up in a certain way and just dig everything, not knowing what I am hearing.  Any repeatable is a digger!

Mitchel

[Jonathan Porter]

29 minutes ago, mn90403 said:

..............I'd have to take a chance on setting the Zed up in a certain way and just dig everything, not knowing what I am hearing.  Any repeatable is a digger!

Mitchel

That’s exactly how I learned, just remember the correlation between range of motion and sweep speed relative to target signal and try and cobble them all together. I am always on the listen out for a broad repeatable response within the threshold, if you get the range of motion and speed right in context with repeatability the signal jumps out at you.

JP

[flakmagnet]

17 hours ago, Jonathan Porter said:

, if you get the range of motion and speed right in context with repeatability the signal jumps out at you.

Sometimes it seems as though the signal jumps out on the third or fourth swing. It's been faintly repeatable up to that point which why you're on the third and fourth swing. My experience many times.

[Jonathan Porter]

5 hours ago, flakmagnet said:

Sometimes it seems as though the signal jumps out on the third or fourth swing. It's been faintly repeatable up to that point which why you're on the third and fourth swing. My experience many times.

What’s actually happening, from a scientific point of view, is as you sweep you are hearing ‘something’, that something is enough for you to continue passing the coil over the zone trying to get the target signal to manifest, incrementally without realising it you minutely adjust and refine the sweep speed, the range of motion (two very different things), centering of the coil relative to the potential target and finally gradually changing the height of the coil relative to the target and bingo the signal pops out of the ether. This sub-conscience incremental adjustment is a big part of the whole gamut of visual, tactile and audio sensory input associated with metal detecting.

Sometimes the sweet spot is so tight that you ‘pop’ the target only every so often as you pass the coil in through the epicentre of the target zone, this happens a lot in saturable ground as the target signal can get blended in with saturation noise so you only have a few millimetres to play with between the saturation signal affecting the threshold and loudest target signal point, this is one of the reasons why I am not a fan of coils that saturate badly!!

A trick to try, when the saturation signal is messing with proximity to ground, is to scrape a wide area over the range of motion target zone because saturable magnetic particles tend to concentrate in the surface soils, scraping them away can give you a few millimetres more room to play with allowing the coil to almost couple to the ground. This method is effective on small shallow targets especially but also beneficial on the larger deep gold that does not increase very much in signal, in fact the lack of signal increase when I clear the saturable materials always brings a smile to my dial because deeper often means bigger.

JP