Question about charcoal when detecting

[Guest]

Hi Guys,

Still trying to get my head around using the gpx4500. As i mentioned before in other posts im a total newbie to using detector and just wanted to know a few things, if any one could help.

First: Went out yesterday for another swing tying out the 6" detech coil over some mullock heaps. Kept getting signals but couldn't find anything. The area has lots of charcoal from previous backburns so i'm presuming that detectors dont like charcoal. Is this correct? Can you set the 4500 to get around this problem or do you just go find somewhere else to detect?

The other thing is in Gippsland at this time of year the ground is super wet. Does this effect a detector at all? Should i be detecting here in the summer months only?

BTW: Got the "Seta Project" DVD by Jonathan Porter coming next week and still yet to do the a training day with Minelab so hopefully i'll understand this beast of a thing before long 8.(

 

[Guest]

That might be a 6" coil, not a 6' coil!

 

[Guest]

From my very limited experience, Charcoal will give a signal and wet mineralised to highly mineralised ground will make your machine noisy to the point where you will have to back off your gain quite a bit.
Enhance
gain 14-8
sensitivity within 2 points of gain. Till you get more experience.

From what I understand with sensitivity. Less is more.

I've heard reasonable things about High Mineral, but haven't really had a crack with it.

Try to find a happy medium with dumbing you machine down. I never run my 4500 completely quiet. Which means more ground noise (bearable) but you will dig more ground noise "false targets". But that's just me.

 

[GypsyGoldAu]

From your post..

"[swing tying out the 6" detech coil over some mullock heaps. Kept getting signals but couldn't find anything. The area has lots of charcoal from previous backburns so i'm presuming that detectors dont like charcoal.]"

Yes the GPX range will signal on charcoal..however, i find it "improbable" that this is the issue you mention on multiple "mullock heaps".

I tend to believe there is something more going on to your story, but without being there it is hard to define what the issue might be.

Perhaps for those who use a 4500, could you please post your settings, and the approximate area/soil types you are detecting on?

Cheers
Gypsy

 

[limpalot]

Great idea Gypsygoldau, would help others with differant detectors as well, to show differances in recepton to soil types on the same detector.Start a new " sight " Settings and Results. Cheers All.

 

[Guest]

Thanks everyone for your help?

As I've got little experience with detectors I'm starting out in factory settings. The basic ones that minelab suggest when stating out. The ones on the back of the manual

The machine is quiet when going over ground that has no charcoal so I know that it's balanced ok. However most but not all of the mullock heaps are covered in ash and charcoal and it just seems that when digging targets that I find lumps of charcoal and nothing else. But the ground is very wet here in Gippsland at the moment so that could be part of the problem. Now that I know charcoal can be a problem I'll detect somewhere else until I understand the machine better.

Rick

 

[GypsyGoldAu]

Jin....if you are set on working in that area, an idea "may" be to spend an hour or two "raking" the heaps first to remove the surface ash/charcoal and then try to detect. At least in this manner, you will negate one part of your concerns as to whether it is your setup or the "charcoal" giving you problems. The charcoal won't be below the surface in the "mullock" and is why i said i found it "improbable" this was your issue. Once you dig the top away and check for a signal there shouldn't be one unless there is something there.

If after raking your 4500 runs quiet, you will know for sure the noise IS from the charcoal....otherwise it will be down to your settings. Perhaps even changing to a DD coil may help lessen the charcoal response as well. Make sure the front end cap settings are to suit the coil your using as well, and run in "fixed" GB with regular "rebalancing".

In this hobby, there is nothing WORSE than self doubt, or doubt in your setup....better to know for sure than to travel away from gold to end up in the same situation somewhere else...imo.

When beginning, lots of mistakes can be made and avoided with a little forethought and less enthusiasm to get the gold. Learn your machine first or spend tons of time making the same mistakes....just in different areas.

Your choice as to how hard you make it for yourself.

Hope this helps..

Cheers
Gypsy

 

[ILikeGold]

From my very limited experience, Charcoal will give a signal and wet mineralised to highly mineralised ground will make your machine noisy to the point where you will have to back off your gain quite a bit.
Enhance
gain 14-8
sensitivity within 2 points of gain. Till you get more experience.

From what I understand with sensitivity. Less is more.

I've heard reasonable things about High Mineral, but haven't really had a crack with it.

Try to find a happy medium with dumbing you machine down. I never run my 4500 completely quiet. Which means more ground noise (bearable) but you will dig more ground noise "false targets". But that's just me.

There is no 'sensitivity' setting on the 4500, thats basically what rx gain is. There is a stabilizer setting which is like audio smoothing, removing information to make it quieter. Most people run there 4500 in enhance, if this is noisy drop back to smooth timings.

The little coil may be making the problem worse, try the standard 11" and see if it does it too.

 

[Guest]

Thanks Gypsy?

I think your right, I don't think the setting are correct for the soil type. As far as the running in fixed, I've been running it in tracking. Sounds stupid but when I get out there I now how to ground balance using the little green button, but wasn't sure how fixed worked. I'll read up on that today.

Your dead right about learning about your machine first. I've spent days online watching YouTube videos, watching and listening to the way the gpx responds to signals. I have read hundreds of forum posts and blog posts about the 4500. I use a mind map to save all the points that I think would help me. Slowly the manual on the 4500 is making sense.

My next step is to watch the seta project, complete the free training day with minelab then do some more training with two different tour guides. Of course the stuff you read and watch doesn't replace getting out and actually using it in the field but it certainly helps me understand the detector a bit better.

I've been out about 5 times now and every time I come home and check my notes things are falling into place.

Last time I went out I raked back the grass and sticks on top of a mullock heap and got a couple of signals but nothing there. I didn't want to rake two much off the surface so there still might have been some charcoal left. But I'm leaning towards operator error. Any how I'll probably leave that area for some time down the track.

Sooo much to learn.... I was tossing up buy the sdc2300 but went for the 4500. People on the forum where saying the 2300 was great for beginners and the 4500 had a learning curve. I'm glad though that I've chosen the 4500 as it's made me have to study to understand it, and I'm learning so many other things about prospecting that I probably wouldn't have discovered.

Anyway next week I'll get my gold fix the old fashioned way, highbanker style. Also got a trommel to try out, it's an old one that was hand operated. I fitted a windscreen motor and welded it to a wheelbarrow frame.

Thanks again, might meet you out that way one day as my parents live in Havelock.

Cheers

Rick

 

[ILikeGold]

Hey Rick, If your running in tracking pushing that green button aint ground balancing, when in tracking the green button stops the auto ground balance and holds it in fixed.

You use the green button and pump it up and down to balance when in fixed.

 

[Guest]

Hey Rick, If your running in tracking pushing that green button aint ground balancing, when in tracking the green button stops the auto ground balance and holds it in fixed.

You use the green button and pump it up and down to balance when in fixed.

Thanks ILikeGold,

I sort of got confused a bit when explaining things. The QuickStart guide says start in fixed then pump the coil. Press green button while pumping coil and then switch to tracking. That's what I have been using. But I wasn't sure how to start in fixed and ground balance. Your explanation made things clear.

So if I was in tracking and got a target I could hold the green button and that would stop the auto ground balance, which would stop the machine from balancing out the target. Is that correct? I think I read a lot of guys mostly use "fixed" and ground balance often.

 

[Ridge Runner]

Hey Rick, If your running in tracking pushing that green button aint ground balancing, when in tracking the green button stops the auto ground balance and holds it in fixed.

You use the green button and pump it up and down to balance when in fixed.

Thanks ILikeGold,

I sort of got confused a bit when explaining things. The QuickStart guide says start in fixed then pump the coil. Press green button while pumping coil and then switch to tracking. That's what I have been using. But I wasn't sure how to start in fixed and ground balance. Your explanation made things clear.

So if I was in tracking and got a target I could hold the green button and that would stop the auto ground balance, which would stop the machine from balancing out the target. Is that correct? I think I read a lot of guys mostly use "fixed" and ground balance often.

Yeah the button pauses the tracking so you don't balance out the target and if the tracking is out you can normally hear it making a noise as you sweep the Coil when you are working in fixed,

 

[GypsyGoldAu]

Hey Jin...no worries at all, it is a big learning curve when first starting and the answers don't always gel in our minds sometimes until we are on the ground practicing with the detector. From the sounds of it, you may have been getting small targets and tuning them out running in "Auto Balance". Have a go using it in "Fixed" on the front end cap, switch on, hold in green button and pump coil to balance the unit, then off ya go (letting go of the green button before doing so).

After a time, if the unit gets a bit noisy, stop and re-balance as above over targetless ground and keep going. It may be a combination of the charcoal & mineralization (hot rocks) that is giving you target responses and then tuning them out as you continue to sweep the same ground while in "Auto" GB.

If you do get back home for a visit, yell out and yeah we can catch up for a stick wave no probs.

Cheers
Gypsy

 

[PhaseTech]

As a beginner I would recommend Tracking. Let the machine do the hard work and it's one less thing you need to remember to do.

Just keep your sweeps nice and wide across a suspected target, and never use Fast tracking with a mono coil.

In bad charcoal areas up your coil size to an 11" round or bigger, and tracking will handle most hot spots.

 

[GypsyGoldAu]

Hmmm...That's a novel approach PT (not that i'm doubting your expertise and it's efficacy) and something i hadn't considered. I just find as a newb when i started out it was confusing trying to understand the responses the detector was telling me and "tracking" only compounded that concern. ie; with the shifting threshold i was constantly asking myself :Hmm, was that a target?" Is that what i should stop & dig?" etc et al.

In addition to that, i was also concerned about the possibility of "tracking" GB actually tracking out the target response as noted above. I could work this way today but when starting, i had too much going on in my head to remember to stop once i had a target and to "utilize" the quick balance switch to "hold" the balance while checking for a target. I was then always having to re-ground balance more often which i found slower & more frustrating than not.

With shifting ground responses the detector sounds constantly busy, and when i had a target it was always easier to just have a fixed balance to "check" the target once scraping/digging had begun.

By all means OP, give this a try, you may find it suits you more than other suggestions, i just know it didn't work for "me". The best thing you can do is to learn your detectors capabilities, and along that journey you will also discover "your" abilities as well. It may well be that this mode of operation IS best suited to you, but you will never know if you don't try to begin with.

Gypsy

 

[PhaseTech]

Yeah it's up to the user to decide what they are comfortable with. In mild-medium ground running in Fixed with the occasional rebalance works well. But in hot ground, charcoal spots, clay domes etc unless you re-balance every few feet you are going to get ground noises and will dig a lot of falsies - this just adds to frustration and dissapointment to a new user.

Even staying in Tracking by sweeping slow and wide across a target area, can avoid 90% of various ground noises, and your risk of tracking out a genuine target is minimal.

 

[GypsyGoldAu]

Yeah it's up to the user to decide what they are comfortable with. In mild-medium ground running in Fixed with the occasional rebalance works well. But in hot ground, charcoal spots, clay domes etc unless you re-balance every few feet you are going to get ground noises and will dig a lot of falsies - this just adds to frustration and dissapointment to a new user.

Even staying in Tracking by sweeping slow and wide across a target area, can avoid 90% of various ground noises, and your risk of tracking out a genuine target is minimal.

Ha ha ha..yeah well...that still happens occasionally, but as i am "on" the goldfields so to speak i am not under as much pressure as weekend/holiday "visitors" and for the few times i get these when out there, i can live with it. Usually i use the tine end of the pick, rake it across the signal (usually much weaker than a normal target, and i might add "assumed" to be gnd noise beforehand) to break up the surface and see if the response changes/disperses. Occasionally i do "dig" the response, but it isn't like a 10" deep, 2' round hole before it's revealed for what it is.

Finding <0.1gm nuggets in the mullock spoils can take longer than determining a gnd noise or not...and again, it comes back to what each operator is comfortable with and willing to operate to. It would certainly be a different matter if i was "living" off the gold, but as this is not the case, i know i always have tomorrow to cover that extra little bit of ground (weather permitting of course).

Also...if i find some dubious gnd noise, usually just hitting the green button & sweeping over the "target" will bleed out and disperse the response anyway (in effect using "tracking").

Like i mentioned above, i could probably operate in the manner you suggest, however i am set in my ways now after 7-8 yrs and "know my detector" (which is the key i think) and can live with "some" extra digging. After all PT... i am digging ALL those targets the SD & DD (w/discriminator) guys left behind....lmao :lol: :lol: :lol:

Gypsy

 

[Bjay]

Hey Gypsy I'm still a relative newbie and basically use the methods you described after getting some advise. Question is if getting a iffy signal an then using button to essentially change to tracking do you think that a deeper target may be missed due to to tracking not supposed to go as deep as fixed? I still dig a fair amount of noise just to be sure though.

 

[walshie1000]

Thought I'd voice my experience as it may be of help. As a lot of you know I've spent a fair whack of time with a small coil (8" commander) on my 4500. I've found that I've always been able to get the 45 to run smooth on heaps with the exception of the small coil being more sensitive to hot rocks/ironstone.

I would start at FP settings in enhance. Assuming the ground is smoking hot I've found changing to quiet audio, motion very slow and adjusting gain and stabilizer to suit conditions is the best approach. I've still found sub .1 nuggets in these settings with lower than FP gain and stab. There's a few other things you can do to however I think that should get you across the line.

Here's a copied reply from another post with regards to GB procedure for both fixed and tracking.

GB method when in fixed - hold the quick track button whilst pumping the coil. Lower coil as close to the ground without touching the ground, hold coil still and release quick track button. (Quick track button depressed for whole gb procedure)

Gb method tracking - press/release quick track button and pump coil until variation in threshold becomes stable.

Hope this info helps

 

[GypsyGoldAu]

Hey Gypsy I'm still a relative newbie and basically use the methods you described after getting some advise. Question is if getting a iffy signal an then using button to essentially change to tracking do you think that a deeper target may be missed due to to tracking not supposed to go as deep as fixed? I still dig a fair amount of noise just to be sure though.

Hi Bjay and thanks for the query. The short answer is.....dig everything to be "sure". This is important while in your formative time learning your detector.

Now to delve deeper....are you talking short narrow weak signals or broad and changing wide & weak signal responses?

The reason being, if you do the 90* sweep as is suggested, then you will find a broad/wide signal one way may only be a narrow/short signal @ 90* sweep. Not always (due to flat pieces sitting vertical in the ground) but usually the last response type will likely be some sort of banded mineralization, and a solid metal target even on the cusp of detecability will maintain the response when sweeping both directions, hence where i stated i do sometimes "dig" these type of signals just to see if the response picks up some as i get the coil closer.

I have been fooled by increasing tones as well as i got closer to the mineralization, but usually in these cases, the excavated soils will also respond in a mild mannered response to the threshold due to the heaviness of the mineralization.

For short narrow weak signals i may just do a surface scrape of overburden, check, and if still unsure, chop at the soil to disturb it and dependent upon the latter response either dig further, or disregard all together. This is because short/narrow responses usually indicate a smaller target and as such will usually be closer to the surface and therefore more readily able to determine if it is in fact a target or not.

Hope that helps, but if it is confusing let me know and i will attempt to clarify my thinking better.

Gypsy