Another Minelab Question, please

[Ken~Digs]

Another question, please. From what I understand the Timings feature Started on GPX (4000) . If this is so, to what Advantage is this Timing feature and when is it used to do what ?

Is it like a Freq. adjust ? Thanks - Ken

[nuggethunting]

Hello Ken,

Well, there are actually different timings on the GP Extreme and up. On the GP Extreme, there are Sensitive, Normal and Enhance. All three of these are actually different timings allowing the detector to do different things (sensitivity, mineral immunity and more depth). In General terms, the Sensitive timings gives you better depth on smaller nuggets and better detection overall on small gold. The Normal timing is best for outright depth on low to mid mineralization. The Enhance timing is best used where there is high mineralization, such as ironstones, volcanics and hot ground conditions.

The GPX 4000 was the first detector to have more timings than prior GP series. The GPX 5000 has 8 timings, the most out of any Minelab or other Pulse Induction metal detector on the market.

Here is some information on timings I pulled from the Minelab website -

Timings refer to the digital switching rates that control the internal electronics of the detector. In the GPX series of detectors the timings generate a pulse train to create the transmit waveform. The same timings generate synchronised switching signals to control the receive electronics.

Selecting different timings and thus changing both the transmit waveform and synchronised receive switching signals have benefits for different ground types and targets. Minelab has created a range of different timings in the GPX series of detectors that achieve optimum depth, sensitivity and ground balancing across different detecting conditions. (Also see “Multi period sensing (MPS)”, “Dual Voltage Technology (DVT)” & “SETA”)

P.S. More timings mean more versatility on different ground condtions and sizes of gold detected. The new Fine Gold timing on the GPX 5000 allows you to detect very porous gold, which wasn't detected very well on prior Minelab PI's.

Hope this helps a bit,

Rob Allison

[DOC]

I'm not smart enough to understand all of that fancy electronics stuff, so let me explain it in layman's terms the way I understand it.

Ground Timings are to a metal detector, like tuning out standing wave in a CB radio.

You get a CB radio, and an antenna. You need to tune the antenna to be optimized to work with channels 1 through 40, so you have to get a standing wave meter and TRIM the antenna to make it the optimum length to eliminate standing wave and push the most power out through the antenna.

Well you can't have 40 different antenna lengths, it would be nice if you could, because then each of the 40 channels would be optimized to the best performance.

So what do you do? Well you trim the antenna to channel 19 because that is right in the middle. So your CB radio antenna is perfectly tuned to channel 19. It's not perfect with channel 1 and it's not perfect with channel 40, but it's acceptable.

OK, stay with me here. Channel 1 are small nuggets, channel 40 are large nuggets, channel 19 are the medium nuggets.

On the older machines, going back to the SD2000 we had Channel 1 and Channel 2 and we ran them together or separately. One channel was tuned for deep large nuggets. The other channel was tuned for shallow little nuggets. We ran those channels together hoping to get the little ones and the big ones.

There are things we know about the pulse in induction machines. Long slow pulses, go deeper and hit on larger nuggets better. Short fast pulses hit on little shallow nuggets better.

There are many different combinations of big nuggets deep, little nuggets deep, medium size nuggets in highly mineralized ground, or mild ground, deep or shallow. Certainly more combinations than 40 channels in a CB radio.

Now recognize that for any of those thousands upon thousands of nugget variables, (size, shape, depth, ground mineralization, etc. etc.) there is a perfect "GROUND TIMING." Ground timings are a combination of the pulse rate, the pulse length, and the variable voltage used in the "Dual Voltage Technology" to approximate a a setting which is closest to the optimum performance that will suit the ground conditions you are in, and find the type of gold you are trying to find. But it would be beyond the current electronic capabilities to be pulsing all of those hundreds of thousands of optimum timings into the ground at once, so we have GROUND TIMING settings. And the more recent Minelab pulse induction machines have more and more settings, to at least come close to common conditions that we encounter when looking for gold. Ground is mineralized, nuggets are medium size and deep. (Hey we have a Ground Timing that is Optimized for those conditions)

So a "Ground Timing" is series of settings that programs the detector for pulse rate, pulse duration, and other variables that will optimize the machine to find certain kinds of gold in certain kinds of conditions."

Does that mean if you are in Fine Gold you won't find large deep nuggets? NOPE, it just means that FINE GOLD is a setting that is optimized to find smaller targets in mineralized ground, finding larger targets is still a possibility, although it may not be the optimum setting to do that.

So in the GPX5000 we have multiple timings, like FINE GOLD. This timing is optimized to find small gold in worked out patches. That setting has been optimized to do just that, find little gold in mineralized ground. The technicians at Minelab have found a there are different timings that find certain gold in certain conditions better than others. In other words, they have tuned the antenna on the CB radio for the exact channel you want to get reception on.

No more do we have just 2 channels, we now have multiple ground timings. The more sophisticated the machines get, the more timing options they will give us. Then the next step will be how top figure out how to get those timings to all work together at the same time so we don't have to select a timing.

Hopefully this gives you a lay man's understanding of what these timings do. They are simply fine tuning for certain ground conditions and nugget variables that makes the machine more optimized to perform in those conditions.

I have an area that has deep nuggets in highly mineralized ground. OK, well we can give you a machine that is about as close to perfect as you can get for those conditions. Just use this Ground Timing! Well I have little nuggets in highly mineralized ground, well I have the perfect machine for you! "Hey wait it's the same machine!" Yes it is, but when I select this different Ground Timing it is going to act like a machine made to find little nuggets in mineralized ground.

Just like if you had an antenna that could be lengthened or shortened to be optimized for the CB channel you wanted to talk on.

Later, if you like, we can talk about what effect dual voltage technology has on the ability to find gold nuggets. And the concept of pulse decay rate, and why newer Minelabs are better at finding small nuggets than the older SD2100. SD2200.

Doc

[fredm]

Wow, Doc...pretty nice explanation for someone "not smart"...good job

fred

[beepinpete_WA]

Alien contacts ???

[nuggethunting]

Hey Guys,

Doc has used a very good Analogy of the two, CB Radio & Antenna's to Detector Timings. Thanks for the breakdown Doc.

Rob Allison