MORE INFO ON THE MINELAB GPX-4000

[nuggethunting]

Hello Montana,

Thanks for the detailed information on the Li-Ion Battery. I'm hoping there will be some type of adapters for the aftermarket Li-Ion systems also, but not sure the Coiltek Pocket Rocket will work even with an adapter. I know the Coiltek Li-Ion System only puts out around 7.3 - 7.4 volts, and seen where the new Minelab GPX-4000 needs 8+ for initial start up I believe. (please correct me if I'm wrong)

Bob, I'm sure you're out hitting some old spots today with the new detector. I'm hoping you do very well with the new machine. Will be waiting anxiously for your first report on the GPX-4000. However, I know you could find gold with a wooden detector and coconuts for headphones!

Take care,

Rob Allison

[montana]

Rob. The low battery alarm starts to sound off at 7.3 volts. detector shuts down at 7.1. ----Bob

[Chris Gholson]

Rob & Bob,

Today I noticed my battery tested out at 8.4V when I first turned on. About 10 minutes later it dropped down to 8.2V. Seems like there is a rapid drop in voltage, but then a leveling off at or slightly below 8V. Did you guys notice this?

[lemons]

Anyone involved with marketing would affirm that taking the user out of the loop will eventually lead to contempt.

Many users may feel that they have subjugated their input to the high alter of technology. I would aviod that if I was ML. There is good reason to leave some functions in the domain of 'fine-tuning', which keeps the user empowered without diminishing the major advance with the Hi-Tech.

Give em something to play with, in short.

lemons

[Jonathan Porter]

Rob & Bob,

Today I noticed my battery tested out at 8.4V when I first turned on. About 10 minutes later it dropped down to 8.2V. Seems like there is a rapid drop in voltage, but then a leveling off at or slightly below 8V. Did you guys notice this?

Chris, I have been saying this for some days now , the Lithium Ion battery for the GPX is not a REGULATED battery, in other words it will charge to whatever the combined cells will take (around 8.5V) and then discharge from there until the detector hits the cut off point (around 7.0V), this should provide approx 12 hours of operating time.

JP

[nuggethunting]

Hello JP,

Thanks for all the help you are sharing with us here. I have one question for you. Since the GPX-4000 is not regulated, do you see a drop in performance when the voltage gets down to 7.5 volts or lower? This was a problem with the SD series since they were not regulated. The SD's towards the second half of the day seems to get unstable and lost some audio, which would cause a loss in depth and sensitivity ultimately. Hopefully this is not the case with the new GPX.

Talk with you soon,

Rob Allison

[Jonathan Porter]

Hello JP,

Thanks for all the help you are sharing with us here. I have one question for you. Since the GPX-4000 is not regulated, do you see a drop in performance when the voltage gets down to 7.5 volts or lower? This was a problem with the SD series since they were not regulated. The SD's towards the second half of the day seems to get unstable and lost some audio, which would cause a loss in depth and sensitivity ultimately. Hopefully this is not the case with the new GPX.

Talk with you soon,

Rob Allison

G'day Rob, what most people need to remember about the GP series is they already have internal voltage regulation, because the unit is already regulated it doesn't matter what sort of voltage you supply initially also Lithium Ion batteries have an amazing flat disharge curve which almost acts like a regulated battery anway (a little like the old Coiltek 6.8V NiMH battery system).

I have never had a problem with the SD series becoming noisy or chattery later in the course of a detecting day, and in most situations found the regulated battery systems to actually cause the SD's to become noisier especially with large mono coils in high mineralisation.

Regards

JP

[montana]

The noise and chatter at the end of the day is some kind of EM interference we encounter here in the states, not the detector battery losing power. If you start with a full battery in the evening you will still get the increased chatter.----Bob

[nuggethunting]

Hello JP and others,

There seems to be some confusion about "battery regulation and onboard regulator" still from customers on the new GPX-4000.

Is the new GPX-4000 equiped with an onboard regulator like the GP Extreme, GP3000 and GP3500? I wouldn't think Minelab would go back to a non-regulated GP after the previous three models have had onboard regulators. A person at Rich Hill today mentioned one of the dealers told him the new GPX-4000 was not regualted, so once the voltage of the battery started to drop you would loose detector performance.

I would think the detector would have a 6v regulator, but the Li-Ion Batteries would charge up to max voltage (around 8.4-8.5) and would slowly drop along the 12 hour period. Li-Ion batteries seem to hold a high voltage and then take a fast drop at the end.

Montana Bob - I experienced the EM Interference today at Rich Hill. It never fails, the second part of the day my detector gets noisy. This seems to happen at most of the places I hunt here in Arizona.

Chris Gholson - Actually I don't have a GPX-4000. I will have my first shipment tomorrow (Monday) since i didn't pick them up at Gold Basin. I'm going to do some testing during the week at some nearby goldfields. I will let you know my findings.

P.S. I just wanted to personally thank Jonathan Porter, Bob "Montana" Dansie, Chris Gholson, Steve Herschbach and others that are sharing information about the new GPX-4000. I'm excited to get my hands on one.

Take care,

Rob Allison