Minelab GPX5000 tips, settings and questions

[Roscoe]

I was reading the GPX5000 manual and from what i have read, it seems to automatically know that you have plug in a external speaker. I can only presume that it senses the ohm's resistance of the speaker. I think that most booster speakers run at 8 ohm, is this correct? Have i interpreted the manual correctly? I would believe that if you were using a 8 ohm external speaker that you would be using more battery power as the internal booster would come in.?

 

[Zakman]

Hmm Roscoe this is to technical for me maybe one of the other have an idea?

Zakman

 

[Ben78]

I was reading the GPX5000 manual and from what i have read, it seems to automatically know that you have plug in a external speaker. I can only presume that it senses the ohm's resistance of the speaker. I think that most booster speakers run at 8 ohm, is this correct? Have i interpreted the manual correctly? I would believe that if you were using a 8 ohm external speaker that you would be using more battery power as the internal booster would come in.?

The stereo plug on the battery pack is wired in a way that if you connect a stereo plug where the mono speaker is wired across the +ve of each terminal that it will switch the amplifier in. The wiring is explained in the manual and is quite easy to to. Yes there will be an increase in power consumption as the power output of the audio amplifier has to increase to drive the larger speaker. The increase isn't great and you'll still get a full days detecting in with speaker or headphones.

 

[Redfin]

Apparently ML have some sort of patent on the Litz but do give permissions to use now and again.
Coiltek have one coil I have heard that use it, and NF have some as well.
Ron

 

[loamer]

Litz - see http://en.wikipedia.org/wiki/Litz_wire

 

[Ben78]

Don't get wrapped up in litz/not litz (lol) Litz is a style of wire. The reason it is used is because each individual strand in the bundle is enamelled, and reduces the internal capacitance of the bundle. Capacitance between strands reduces the ability of a coil to decay at the short timeframes required to sample and still detect very small gold. Litz wire was originally designed for high speed RF communication data lines, which specifically needs low internal capacitance to conserve the signal. Seeing as Litz isn't the only option in the high speed RF world there are other cable solutions that can be used and still achieve the fast decay times required for detecting small gold. For all anyone knows Coiltek may well use Litz, or Shenzen Ziang brand of individual strand enamelled low capacitance wire but choose not advertise the fact. (It has been suggested that the Coiltek Goldstalker bLITZ may well use Litz brand wire.)

 

[Zakman]

Thanks Loamer, Redfin and Ben

i now understand the Litz. didn't know that coilteck had some coils using Litz.

cool Zakman

 

[peterau]

Hi All, got a couple of questions, dont laugh, but I honestly dont know the answers. Is it possible or even o.k. to charge my gpx 5000 battery from a jumpstarter power pak. Like plug the 12v charger that came with the 5000 into the power pak and into my 5000 battery. Also how long roughly does it take to charge a 5000 battery from my car battery. Now remember dont laugh, but do I or can I have the motor running, i.e. sitting stationary running or driving with the 5000 battery charging or motor left off while charging. Dont want to stuff my 5000 battery so will ask to make sure. Hope some can help Cheers Peterau

 

[Ben78]

5000 battery has a charge regulator built in. The manual describes the charge states by looking at the LED. You can use the car charger supplied with any 12v source (car, jump pack, desktop power supply etc)

Off the top of my head I don't know the charge rate or capacity of the battery so I'm gonna go and say that for each hour of use expect half hour to an hour on the charger.

You won't stuff the 5000 battery if you use the supplied chargers in accordance with the supplied manual.

 

[Zakman]

Thank's Ben that's what I thought, yes I will go with the correctly wired speaker and leave the boosters for later.

Zakman

 

[loamer]

Just one thing with the speaker - in my case, windy days in the bush can have an effect along the lines of the noise of the trees and the wind can mask faint threashold signals, I found myself leaning towards the speaker to try and pick up the faint noises. I also found that ground noise got blurred with target responses - it was hard to differentiate with the wind noise. I always carry a set of good headphones (Koss) in my day-pack in case the wind picks up too much. Had these sort of problems on the weekend in high winds - switched to the headphones and all was good. I have trialled the under chin ear plugs - in my case a failure - I am too tall too tall, leads too fragile, required an adaptor etc. failed test. Apart from that minor issue, the speaker will work fine for the day and not draw too much extra power and I believe they cut down on ear fatigue a lot.

 

[Zakman]

Thanks Loamer as always great points . I have so much fun ahead in this learning curved just need to find that first nugget . Hopefully its a huge one hahaha
Zakmman

 

[HeadsUp]

interesting thread

i am playing around with my rooster booster

i hate the long leads

i hate any leads

so i want to shorten the leads on the rooster booster , attach it and the aftermarket battery on the side of the control box and keep it all compact so i am not restricted when digging targets

i want to be able to just work on my knees and leave the detector next to me without leads getting tugged on every time i swing the pick

anyone else carried out mods to their battery and cables to do this ?

i know there will be days when i have to use headphones and other days when the speaker will be a winner so making them both easier to use with as few cables as possible is on my list.

 

[Ben78]

Coiltek sell short battery leads so you can do this. I reckon a small LiPo Turnigy Nano style would make a great battery pack to tack on the side.

 

[HeadsUp]

Coiltek sell short battery leads so you can do this. I reckon a small LiPo Turnigy Nano style would make a great battery pack to tack on the side.

5000 or 10000 mAh turnigy battery at 7.4 volts or 11 volts if you include an output voltage regulator . 290 - 500 grams . runtime 4.5 hours and 9 hours

canon NP-F750 camcorder battery 7000 mAh , 7.2 volts 100 grams run time 6 hours

the turnigy battery is great for high discharge and charge rates ( 20 - 25 C ) which we dont need on detectors but they pack an awesome punch

the issue to watch with detector conversions is to maintain the maximum voltage with a regulator

more study required on that one

 

[Nightjar]

Only ever charge our Minelab batteries with a 12V supply. Plug them in at the end of the day and leave them on charge overnight, ready for an early start next morning.

 

[Ben78]

I was looking at this one

I don't believe I would need a regulator on a 5000 as the control box does that and has low voltage cut out.

 

[Roscoe]

Ben78, I re-read the manual, i see what you mean. I think for the GPX5000 i would buy a premade GME speaker that was already wired correctly and do what loamer suggested. Use the speaker, if to much noise around put headphones on.

 

[Roscoe]

I have a 24 x 12 coiltek UFO coil at home. Can this coil be run any good on the GPX5000? I would like a large mono patch finding coil, preferably a elliptical design. Is any one on the forum running large mono's on the GPX5000, i would be interested to here about your coil choice and experiences, thanks roscoe.

 

[Ben78]

Yep, best way to do it. I have the speaker there ready to go when I want but I mostly use ear buds, a lot easier to concentrate on the audio if all you can hear is the detector.