Hi all,

some of the guys want to dig deep. Much deeper than 1 m.
(    )

Chasing the big ones. Which can't be detected with the current detectors and coils.
They are still there. Lot's of them. The big and deep gold.
Just below the impenetrable magnetic field shield (the heavy ground mineralization layer).

Pity, that no one has made such a detector during my absence yet.
What's happened?
We know how to do it.

Aziz

Hi WM6,

I see, that GPZ had a software update for ground tracking.
Yellow ferrite is a substitute for a hot rock. Oz guys don't need to buy this ferrite. They have lots of hot rocks lying around there.

"Special instruction needed."
Already done in the past.
Aziz

 The deepest Pi detector ever developed in my opinion was a prototype  SD2000  that BC modified for the late Jim Stewart.BC slowed down the clock speed  to give a very long pulse and made some other unknown changes to the circuit to cope with higher currents etc. At the time the SD2000 came out BC stated that it was at about 95% of the maximum potential depth that any hand held PI could ever achieve (and still pass emission  standards). However the deepest PI that has ever been made for gold was Corybns detector which detected a  nugget of around 10oz? at 3 feet in depth in WA. Some where on the forum is a reference to it and i will try and find the link when i have time.
doug

Nothing new with Ferrite being included with Detectors, my first whites a 5000D VLF had a piece of Ferrite included in the box, used as a sample to set up the manual GB.

The Ferrite represents a mineral sample or negative (hot rock) as opposed to a rusty nail or piece of Ironstone or Positive (hot rock)
Ferrite will Null the threshold when the coil is passed over it, creating a Bong sound as the threshold recovered
These rocks were known back in the day as bongers.

To combat these negative (hot rock's) on a Manual GB machine, the QED for example, is to run a slightly positive offset on the GB.

Is that by adjusting bias up slightly from null, or by using a slightly higher GB

Hi all,

I have just checked my basement and it seems, that I have really enough iron oxide so I don't have to buy more.
Some of the samples must be converted into a strong magnetic maghemite. But I also have quite amount of maghemite samples.

I hope, that I can show the magnetic field shielding effect of the high mineral ground layer by making simple induction measurements (TX -> RX coil sensor). The result will show, that a special coil confuguration can cope with the effect and we already know what kind of coil is the way to go.

BTW, I also have found a bag of nearly 5 kg FeSO4 (ferrous sulphate). I could turn it chemically into iron oxide using a tube cleaner (containing NaOH) but would take some time. I am testing this process with a small amount and an air blower to oxidize the resulting Fe(OH)3.


This experiment is part of the big deep gold detector (regarding the coil).

Cheers,
Aziz

Hi Ron,

why not. But I don't think, that dry salt is going to make problems. Wet salt is another issue of course.
Aziz

Hi all,

I am just wondering why ML is using a Super-D coil for their GPZ. A concentric IB coil would punch deeper in those mineralized grounds.

Aziz please don't tell them to much or they will pitch your ideas as I believe they have done in the past.

Cheers.

 I see that this topic has been raised on SH forum. As  expected JP chimes in and claims the SAD7000 will" thrash" any PI for depth on large nuggets. He of course provides no evidence to substantiate this or any electromagnetic  or electronic or technical reasons as to why this should be so. As usual he only tells half the story and while he refers to the 1/r^6 law he does not say that this is  one the of main factors in detecting larger conductive objects at depth ie the the diameter of the TX coil will ultimately determine the depth at which large  conductive objects can be detected. Corbyn coils were from memory about 36” in diameter. I have no doubt that the late JS modified SD2000 with his 36” coil would thrash the SAD7000  for depth on most very large, solid  highly conductive nuggets.
 The diam of the TX component of the SAD 7000 DOD coil will ultimately  be one of the key factors in determining how deep a large conductive object can be detected. You cannot escape the laws of physics regardless of what signal acquisition/processing wizardry you use!  In addition for large ,highly conductive objects you require a long exposure time to the  energizing Tx field   and the energizing field needs a lot of low frequency spectral content.
doug