Minelab GPX 6000 vs GPX 5000 - 17" Coil Test - Gold Prospecting in Australia - Extended 

because ground and emi conditions called for it. even on 1, it is still an extraordinary machine! Run it too hot and you will drown out faint targets with ground and emi response. When your sensitivity is too high for the ground, the machine will not settle / ground balance properly, and this will most definitely lose you targets - occasionally less is actually more ;)

@@MinersDenAustralia thanks man great explanation, would you loose depth Running on 1 in the same situation to compensate for ground noise and emi?

it is a common misconception the sensitivity = depth. Sensitivity is really a layperson term- it really should be called RX gain. The machine is always punching to its maximum depth. When you go up in sensitivity, the machine applies extra gain to signals making them louder- be they target, ground or interference. If you are getting too much ground and emi noise, you simply wont be able to hear the targets right at the limit of the machines depth capability as they will be drowned out by unwanted noise. Running a lower sensitivity will reduce the overall volume of targets, but because you are not getting all the unwanted noise, these quiet targets become much easier to hear.

frequency is most applicable when describing vlf machines as they are a constant transmit and receive. PI is a bit different in that they transmit, switch off, then recieve many times per second, so they don't usually use a frequency to express / describe this to the general public. On say the Gpx5000 there are 8 different timings each with differing lengths and slightly differing tx frequency. If it helps any, as an eg i think the sdc's tx frequency is around 3khz and the Gpx6000 1.5khz. (don't quote me on that though!). High frequencies are important for Vlf machines used for gold prospecting, as higher frequencies will excite low conductive targets (ie tiny gold nuggets) better than a low frequency, which excites high conductive targets better (ie silver). Pi is different again in that the pulse timing is the more critical aspect rather than frequency of tx, and don't even get me started on Zvt (Gpz 7000)

@@MinersDenAustralia please more, as an elicrical engineering graduate this is epic stuff more more more or wher can i read about the tech?

have a look at this article from Minelab- www.minelab.com/__files/f/11043/KBA%2000-1%20Metal%20Detector%20Basics%20and%20Theory.pdf

should be a little better on the 6000- but every nugget is a bit different