changing that depth chart for Victorian conditions

On the depth chart that Minelab put out in the white paper I`ve been studying that chart and I realize that from at least my perspective, when I had a 5000, I almost NEVER used normal timings and I very rarely use normal timings on the 7000 because Victorian ground is just to damn noisy, so I figure the blue, purple and grey dots can be taken off the chart for Victoria.
I don`t know if that X axis is constant. 1 is a 600 grammer and 30 is a 0.13 grammer
Does that mean 15 is about a 300 grammer???
I have no idea, but whatever weight nugget 10 is on the X axis, this chart is saying general will get the nugget 18% deeper than the 5000 but high yield will get it 34% deeper.
Is 10 on the X axis a 400 grammer???
I have no idea.
There are way more red dots than yellow dots and this chart is basiclly saying that for nuggets up to weight 7 (whatever weight that might be), we should be running High Yield.
Or have I got this chart completely wrong?
cheers

Hi Phoenix  -  I was bored and saw your post from last Aug and decided to stimulate my brain.  

Normal--
On the depth chart that Minelab put out in the white paper I've been studying that chart and I realize that from at least my perspective, when I had a 5000, I almost NEVER used normal timings and I very rarely use normal timings on the 7000 because Victorian ground is just to damn noisy, so I figure the blue, purple and grey dots can be taken off the chart for Victoria.
--I agree  

X axis--
I don`t know if that X axis is constant. 1 is a 600 grammer and 30 is a 0.13 grammer
Does that mean 15 is about a 300 grammer???
I have no idea, but whatever weight nugget 10 is on the X axis, this chart is saying general will get the nugget 18% deeper than the 5000 but high yield will get it 34% deeper.
Is 10 on the X axis a 400 grammer???
I have no idea.
--The X axis appears to be just a size-ordered numerical list of nuggets from #1 (20oz/~600g) to #30 (0.13g).  You can not "interpolate" easily (at all ?) over the range described.  For instance, nugget #2 MAY be 1g (ie. the chart is mostly small nugs) or nugget #29 MAY be 599g (ie. the chart is mostly large nugs) etc !  

Data points--
There are way more red dots than yellow dots and this chart is basiclly saying that for nuggets up to weight 7 (whatever weight that might be), we should be running High Yield.
Or have I got this chart completely wrong?
--A comprehensive table would also show the gpX result and therefore have THREE data points for EACH nugget size.  It may be OK to leave out the gpX points because the chart has a Y axis of "% over gpX" etc.  But not having ALL pairs of gpZ points leads me to think that BOTH settings were NOT tried on ALL targets - and that the data may just be a collection of "random reports from the field" with no real control over data gathering etc ?  NOT having the gpX values looks suspicious - but there surely is a lot of data about them ?  IMO a range of standard targets/air-tests would be more statistically rigorous and a better starting point ?  

Cheers - Phil

Auger wrote: NOT having the gpX values looks suspicious - but there surely is a lot of data about them ?  IMO a range of standard targets/air-tests would be more statistically rigorous and a better starting point ?
Cheers - Phil

Yeh that chart really doesn`t say a hell of a lot.     I think the GPX values are represented as zero and it shows that weight 15 had no depth advantage over a GPX.
The Y axis goes to -10%, so this chart is saying the 7000 NEVER performed worse than the GPX on the nuggets tested.  I wonder whether that is true.
There is no doubt in my mind the 7000 is a better detector and no way would I go back to a 5000 but I suspect that most of these "weights" on the X axis would be 10 grams or less.
It constantly amazes me that in 12 months of detecting almost daily in what was one of the richest gold fields in the world I am yet to detect a 30 grammer that was out of the range of a gpx.  99.9% of the gold I have found with the 7000 is under two grams and MOST of the gold I have found is under one gram  
BUT
today is another day  
have a good one
dave

Dave,

"you're looking in the wrong place"    

Phil

lkyphl wrote:Dave,

"you're looking in the wrong place"    

Phil

Thank you Phil
We both know why you said that and I got a good laugh out of it.

Phoenix

gpX values--
I think the GPX values are represented as zero and it shows that weight 15 had no depth advantage over a GPX.
Yes - I'm sure that is the intended/reasonable assumption. However, it would be interesting to see the entire data-set and any accompanying comments about geological/environmental conditions etc.

chart trends--
The chart does show the complementary (fuzzy ?) trends between Difficult+HighYield and Difficult+General for smaller and larger nuggets respectively. It's always reassuring to see some basis for recommendations in the set-up procedure etc.

lack of "negative" values--
In reality, the "noise-band" may be as much as +/-10% and so ANY values near zero could be a bit "fuzzy" either way ?

Cheers - Phil

dont no where abouts in Victoria you detect phoenix but on my two trips to vic from WA am amazed at how quiet the ground over there is!! was able to use my 4500 in extra on the first trip and last trip using the 7000 could crank the settings rite up with no problems. in WA some of the ground is so noisy with the 7000 its almost imposible to work it regardless of what settings you use

Hey Nigel
I only said the detector was noisy when set in "normal" ground. My experience that`s also the case over here with the 5000. I don`t know anybody that detects in "normal"
I think the 7000 is a beautiful quiet detector when running in "difficult"
cheers