What Are Timings?

[Steve Herschbach]

9 hours ago, phrunt said:

The one timing chart that's missing is this one, this one I found easiest to understand before moving onto the more detailed charts.

Steve has a great collection of the timing charts here, however this one was missing.

 

It was acquired from this Minelab document, the document was the likely cause of Americans running around using fine gold thinking it was the best setting, because of this statement in the document describing the new fine gold timing, "Awesome in US goldfields! Easily finding 0.03dwt nuggets in heavily mineralized, “hot rock infested” ground, using the super sensitive Monoloop coil."

It makes me wonder if I should have been running around myself in sharp, and not sensitive extra like I did with my mild soils.

 

It's right there in the main chart on my GPX timings reference page. What you are posting is derived from the full chart but the version you posted does keep it simpler as long as people know how to read it. The most important part is the methodology for finding the proper setting, which the full chart includes in bottom right. In general the paradox of PI is that as you follow the chart left, the settings are progressively less powerful. Yet they actually perform better in increasingly bad ground. Ultimately it is no different than what we have to do with VLF - AS CONDITIONS WORSEN, REDUCE THE POWER/GAIN/SENSITIVITY! A very simplified way of looking at the Minelab GPX timings scheme is to treat it as a base level gain setting. Minelabs recommended methodology is exactly what I have done with both VLF and PI for decades. Learn to tune the detector to the edge of ground feedback, and ride that edge, adjusting as needed when ground conditions change.

 

[phrunt]

Timings are one of the most confusing things about the original GPX series, once you've got a good handle of them, I don't really think it's all that much more complicated than many modern high-end VLF's, in fact some like the Legend that are notoriously hard to navigate can be just as difficult to understand as a GPX.  

Now we have the new GPX 6000 detector, some of the benefits of having multiple timings are being realized.

[Aureous]

Before selecting any timing change, lower your gain as Steve suggests. The legacy GPX units ALL have receive gain only, NOT transmit (until you get them modded). ML's idea of 'gain' is akin to cranking open your ears, allowing more audio reception rather than any actual increase. Its a filter allowing more % of receive signal into your perception for your own ears/brain to determine audibly whats an actual signal and whats ground noise. Only modding accesses the transmit circuitry to allow actual gain.

[Doc]

On 4/11/2024 at 7:25 AM, Steve Herschbach said:

 

It's right there in the main chart on my GPX timings reference page. What you are posting is derived from the full chart but the version you posted does keep it simpler as long as people know how to read it. The most important part is the methodology for finding the proper setting, which the full chart includes in bottom right. In general the paradox of PI is that as you follow the chart left, the settings are progressively less powerful. Yet they actually perform better in increasingly bad ground. Ultimately it is no different than what we have to do with VLF - AS CONDITIONS WORSEN, REDUCE THE POWER/GAIN/SENSITIVITY! A very simplified way of looking at the Minelab GPX timings scheme is to treat it as a base level gain setting. Minelabs recommended methodology is exactly what I have done with both VLF and PI for decades. Learn to tune the detector to the edge of ground feedback, and ride that edge, adjusting as needed when ground conditions change.

 

That's great Steve, thank you for posting it again.

Doc