GPX 4500 noisey

[Chuky boy]

Hi fellow members. I took my GPX 4500 out today in maryborough VIC. Had problems with signals going out of control. IT was setting of as a target with pretty much every swing and on every part of the ground. I broke apart one rock and it looked as though it was full of small iron pellets. I guess it is due to the highly mineralized soil. My settings consisted of Search mode: GENERAL, soil/timing: ENHANCE, ground balance: TRACKING, coil/rx: MONO. I was running a 11" mono commander coil. Has anyone else experienced this? any help would be much appreciated.

 

[mbasko]

Did you tune it? Did you do an initial quick ground balance? What was your gain & stabiliser settings?

 

[Chuky boy]

hi mbasko, just used the auto tune button on the front of the machine. gain at FP8 and stabilizer FP 10

 

[mbasko]

When you start out next do the auto tune again, use the same settings, but put in fixed, press the quick track button & pump the coil until the threshold stabilises then put into tracking if wanted. Most just run in fixed though & quick track as required or fairly frequently to make sure it stays balanced well.
Check you coil connection is ok too plus the cable is reasonably tightly wound up the shaft to minimise movement.
Without seeing those rocks they sound like basalt which can be an issue. Maybe try an area without those same rocks or a bit less mineralised first then if it seems ok retry the other spot.
Other than that you could post & see if someone close by can give you a hand or check it out. Doing a training day would be good to if you can.

 

[reynard]

hi chunky I was in Havelock last Thursday 23 july and both my wife and I had the same problem, we both run 4500,s I swing a 17/11nf and my good lady a14/9 nf
I normally can run flat out and quiet but had to dum it down heaps for about an hour then the problem eased and I could crank it up again. the day before at Dunolly had the same problem and so did my mate with his 5000 and again it only lasted about 1.5 hrs do not know why

 

[Chuky boy]

thats a strange one reynard. hopefully I can suss it out next time it happens to me. At the time couldn't really identify any sought of target it was screaming with pretty much everyswing every where. And too mbasko i've done the basic 3 hour training day at minelab bendigo and am thinking of doing the day tour with the coiltek crew in maryborough.

 

[Nightjar]

Try ground balancing in "general" then flick to "enhance.

 

[Guest]

Maryborough and dunolly can be pretty noisey' my guess it's just mineralization, if you sweep the coil off the ground 1" does it help?
If it does choose another timing or at worst a DD coil.

 

[mbasko]

The only timing that might be a bit better than enhance in bad ground is sensitive smooth but at a loss of depth.
Setting off like a target on pretty much every swing on all parts of the ground sounds like a balance or coil issue. I've run in fine gold & enhance (5000) around the Dunolly area & it certainly wasn't sounding off like a target on most swings. The odd hot clay dome etc. but the ground should be able to be tamed well enough to detect with the 11" mono. The ground was wet when I was there too & that can create some noise on some ground but not really what you're describing.
If you can get your hands on another coil that is known to be ok then that would be worthwhile checking too. You could have a u/s coil or coil connection.
Noise that last an hour or so could be damp/wet ground or not ground noise but spherics (EMI). Moisture or heat are the only things that that can dissipate from the ground & reduce noise. I'm guessing it's not heat at the moment.

 

[Heatho]

I'm with Matt, try to borrow a good coil and see if there is any improvment, try a different spot too, if it is ok with another known good coil then your coil has had it.

As Matt said also Basalt hot rocks can be a real pain, I found a spot one time where you can't swing a coil at all there were so many, like 5 or 6 every swing, they were how you describe "full of Iron".

 

[SteelPat]

I was out in Maryborough yesterday and the ground was very noisy. Being Ironstone and wet, it was causing all sorts on noise issues. It was even making the machine noisy when the coil was up off the ground. I put it down to the wet ironstone acting like a giant antenna pulling in all the stray EMI. It was very difficult to noise cancel yesterday.

On another note - did you notice all the unfilled holes? I spent half my time refilling other peoples diggings. If you see recent unfilled holes, kick dirt back into them so we dont give Parks any reason to close down the area to prospectors.

 

[Chuky boy]

SteelPat I did notice a few unfilled holes. alot of the holes were surface scrapes. But the soil was really saturated where I was and the mullock heaps were covered in very thick moss.

 

[SteelPat]

I wasn't detecting near all the mullock heaps and these weren't scraps. I think most of these were where someone had just dug hot rocks and was a little peeved lol.
I think it was definitely a combination of the ironstone and rain that made it all very noisy though. I did a bit of research and think I have armed myself with a bit more knowledge on how to combat these noise issues. Look up 'bogenes setup' as I think the settings will apply to the GPX series as well as the GPZ. Basically it's turning the threshold right down and sensitivity up high.

 

[Chuky boy]

I will difinantely be looking this up stellar. I wish the rains would give us a break lately. I'm itching to get out there on a sunny day. Doesn't help that I own a 2wd vehicle almost get bogged every time I hit the unsealed roads.

 

[SteelPat]

I have a Vito van so in same boat. A friend of mine who is in CFA and who has a bobcat business, told me a trick he uses .... Take some lime to spread on any clay you are sliding on. It also makes mud a bit sticky. I now take a big tub of lime with me now just in case.

 

[Kenlily18]

Its strange that I am hearing all about Maryborough vic . I was out today The 23rd with my GPX 4500 , with the same issues , nearly every swing was getting signals . I was using FS Gain 8 stabilizer 10 Enhance , General ,very slow , fixed .
I did auto tune, ground balanced , as I moved being on fixed re ground balance every time I moved on . I felt with the ground damp and obviously high mineralization of the ground and hot rocks didnt help matters . I got a good signal I thought dug down to about 10 inches found out it was hot rock Stone grrrr . The only thing is on my journey detecting I tried to calm the noise down by reducing the gain to 6 with Stabilizer 8 the machine was running much smoother . I am still learning about my GPX , that stetting seem to cut out some of the noise. Later went back to factory setting and kept the coil flat on the ground all the time seemed to help also .happy gold detecting ,can be very frustrating . Cheers

 

[mbasko]

What coil?
Did you try Sensitive Smooth? Worthwhile trying in difficult, shallow ground but you will loose some depth on large, deep targets.
https://www.detectorprospector.com/...lab-gpx-4000-4500-5000-manuals-timing-charts/

 

[stevewilko]

Gentlemen: I concur!
Maryborough, Havelock now.
Past week - increasing ground noise reception.
Hard based ground, on a slope to diggings 150 metres away, minimum top soil.
My 4800 with ML 11" DD and couldn't shut it up.
Halved the rx gain, stabilizer down to 3 and chronic with 'swear its a target' signals all day.
Odd these reports coming in in numbers.
We having a magnetic pole reversal happening now (??!!)
Cheers Wilko.

 

[limpalot]

I was wondering if a smaller coil would be better. Less area to pick up signals a 8 would be the same as the 2300.

 

[stevewilko]

Howdy Limpalot,
I was down to the 11"DD purely to loam east west of the fall to prove gold was on the slope.
For me it was to work with the annoying noise for the hours required and take a good 100mm off any louder 'target' and move on. Only takes a minute to do.
To answer you a smaller coil again would assist but the condition experienced it seems remained prevalent regardless - as the others have mentioned their choice of the coil size.
Cheers,
Wilko.
p.s. I didnt pick up gold there for 7 hrs coil time. Thought it worth a try it looked good!