Air Swing- How deep does your detector ping Gold nuggets?

[Twapster]

I'm doing a little research on what detectors detect gold and at what depth.

Current analysis is the following:

Model: Xterra 70 / VLF
nugget Weight - .5g / .87g
mode: prospecting / no other information
coil size: 6 inch DD
accuracy level: ruler with gold stuck to blue tack (ruler method)
depth: 10cm / 13cm

In All Metal Mode

depth: 2.5cm / 4.5cm

Model: F1A4 Stock / PI
nugget Weight - .5g / .87g
mode: Search / no other information
coil size: Stock 8 inch mono
accuracy level: ruler with gold stuck to blue tack (ruler method)
depth: 8cm / 10cm

Anyone bored with a piece of REAL GOLD nuggets only.... feel free to add to this AIR SWING research.

If you need to add "factors" to the test that's fine.... but the main focus for simplicity is: machine type, nugget weight, mode if applicable, coil size, way you did it and most importantly how deep did she go.

Would be great to know what detector is finding gold at what levels. This thread could once and all solve...or complicate ....the question of what detector to buy if I want to find gold.

Any takers?

 

[downhalo]

Well I can't help with the X-terra..

I've got the F1A4 "stock and modded" covered.
I can substitute 2 other VLF detectors, Fisher Gold Bug SE, and Eureka Gold..

Things to note with VLF detectors.
You'll get great depth in air tests, but the second you hit some moderately mineralized ground, that all does away.. and in comes the noise.. You don't get much if any of that with a PI.

I'll do some air tests with an Unmodified F1, and Modified Plus the Fisher, and Eureka..

 

[downhalo]

Well I can't help with the X-terra..

I've got the F1A4 "stock and modded" covered.
I can substitute 2 other VLF detectors, Fisher Gold Bug SE, and Eureka Gold..

Things to note with VLF detectors.
You'll get great depth in air tests, but the second you hit some moderately mineralized ground, that all does away.. and in comes the noise.. You don't get much if any of that with a PI.

I'll do some air tests with an Unmodified F1, and Modified Plus the Fisher, and Eureka..

Update:

Okay.. Here goes..

F1A4 Unmodified

Model: F1A4 Stock / PI
mode: Switch on and swing..
coil size: Stock 8 inch mono - 11" mono
accuracy level: Ruler, gold in gold pod being moved by hand (does not effect PI)

Nugget .11g, depth: 8cm
Nugget .21g, depth: 12cm
Nugget .51g, depth: 14cm
Nugget 1.32g, depth: 17cm

All air tested on stock F1A4, depth difference between unmodified and modified is 2.5-3cm

---------------------------------------------------------------------------------------------------------------------
Fisher Gold Bug SE

Frequency: 19kHz VLF
mode: All Metal
Coil Size: 5" stock coil
Accuracy level: ruler, nuggets swept in front by my PWM controlled fan, running at 4RPM with nugget taped to the end.

Nugget .11g, depth: 7cm
Nugget .21g, depth: 9cm
Nugget .51g, depth: 11cm
Nugget 1.32g, depth: 15cm

Note: all VLF targets were Audible via threshold drop-out before the detector sounded off (not really reliable in toasty ground)

---------------------------------------------------------------------------------------------------------------------
Eureka Gold

Frequency: 60kHz VLF
mode: All Metal
Coil Size: 10x5" stock coil
Accuracy level: ruler, nuggets swept in front by my PWM controlled fan, running at 4RPM with nugget taped to the end.

Nugget .11g, depth: 6cm
Nugget .21g, depth: 8cm
Nugget .51g, depth: 13cm
Nugget 1.32g, depth: 15cm

Note: all VLF targets were Audible via threshold drop-out before the detector sounded off (not really reliable in toasty ground)

After running around with VLF machines for the past 4 years, I am enjoying the serenity of the PI.. so much less noise..

Final thought, They're all good machines, But the White's SPP! Warranty! also really decent power..

Hope some of this helps.. if not have a mod delete it.

 

[Twapster]

Wow a bit of a difference on the .5g nugget on Stock F1A4's mine 8cm air swing, yours .51g went 14cm?

Agree with VLF being an issue....while it goes 10cm+ in prospecting mode, I have to dumb it down as it will squawk at everything so not really a good test other than to show its capability in some conditions.

I've always been interested to know what models will do what yet try find anything on nugget depth tests on the internet cant find anything. I'm hoping a fellas out there can join in the testing maybe on a rainy day if they have a nugget to test on.

Peter

 

[Nugget]

Garrett AT Gold

Mode: All Metal
Coil: 5x8" DD Stock
Factors: Sensitivity @ 100%, Threshold @ 0
Test Type: Indoor air test, Gold in hand
Measured by: Ruler

Air Test Results
Gold Nugget - 1 gram - ID 51 - 17cm
Gold Nugget - 0.5 gram - ID 39 - 13cm
Gold Nugget - 0.4 gram - ID 37 - 12cm

More test results https://www.prospectingaustralia.com/forum/viewtopic.php?id=237

Cheers,
Nugget

 

[downhalo]

Easily yeah. I use Koss ML headphones.. it might make the difference. also Your nugget isn't my nugget, mine was a flat bit..

And you're right, not much info around on nugget test depth, and if you get any info, its more than likely bull!@#$..

I test mine with my ruler and they're in no way 100% accurate.. nobody has that kinda free time, i was up until 3am doing those tests last night.

My feeling is, if the F1A4 ignores 90% of ground noise, its better than pretty much every VLF, It will find small shallow nuggets, and I've tested multiple coils and found that the 11" commander mono is the best for coverage, depth and sensitivity.
The 8" stock or 8" commander being the best most sensitive... but yah, all rounder 11" mono..

I'll try knock up a video of the nugget tests for the F1.. bit hard with the TV's computers etc, makes for a noisy machine.

 

[Twapster]

I guess i'm buying a set of headphones, and indicates the importance of these devices if stock speakers aren't that crash hot. My .5 nug I reckon is just as flat. So have lost about 6cm..... that's a lot by not using headphones. When I have headphones will post the results again.

I have to stress to new prospectors.......while the VLF Xterra 70 appears to ping deep compared to the PI F1A4, the reality in the field is a squawking machine is an annoying machine.

As Downhalo suggests, the PI will remain much more quiet and not go off every metre on hot soil/rocks like the VLF will, and essentially ruin your day if you are after gold targets. If you "dumb the machine down" you immediately loose min 50% depth if not more.

Its the difference between "happy to walk around all day swinging" and "this is giving me the ***** my ears are ringing I give up" after half an hour.

Id love to see how the SD series compares to the F1A4

Nuggets 17cm on a 1g is impressive.

 

[downhalo]

My theory is, the 2200 machines will beat out the F1.. maybe.. wish i owned one to test..

 

[Heatho]

Aldi detector,

Switch on and go, all metal mode, factory preset everything.
Indoors, air test.
1.15g Gold nugget in hand. 3cm

GPX 5000

Coil, 11" DD
Modes, General search, Fine/Gold timing,
RX, Cancel due to severe EMI in the city, factory preset everything.
Outdoor test, target in hand. 1.15g Gold nugget 11cm

That's almost about as dumbed down as the 5000 can get regarding depth and sensitivity. Would get a lot more depth with a mono and fiddling with the gain, stabiliser and audio settings.
With a mono on it will pick up an aluminium or steel can from about 3 feet.......

Air tests don't really prove too much though due to the "Halo" effect of a long buried target.

 

[Twapster]

Tks Heatho for the input, agree air tests are only an indicator. Good to see a GPX in the mix to compare notes.

At least someone considering buying a Gold machine can use some of the info to assess/ align their expectations on broadly what size of nuggets go to what depth.

I'm gonna have to borrow Jonno's 100gram bar to see what my detectors do on that piece!

Hope more detectors can be entered into this little research list.

 

[downhalo]

Air tests don't really prove too much though due to the "Halo" effect of a long buried target.

My theory is air tests impede the PI's ability, I'm sure that 11" DD would go much deeper on a 1 gram nugget in a field test, could be wrong.. but as you said, the GPX has settings coming out the butt.. always room for improvement.

 

[Greglz86]

Had a play with the xterra 705 with the gold coil yesterday afternoon. I could pick up a .08 gram picker from 3cm away. The sensitivity was on 20, iron discrimination on 5 and the automatic ground balance turned on.
Greg

 

[Heatho]

Air tests don't really prove too much though due to the "Halo" effect of a long buried target.

My theory is air tests impede the PI's ability, I'm sure that 11" DD would go much deeper on a 1 gram nugget in a field test, could be wrong.. but as you said, the GPX has settings coming out the butt.. always room for improvement.

In "Cancel" on the Rx you lose about 1/2 of your depth on a 5000 with a DD. In DD mode with the 11" DD it would probably detect quite a bit further than 11cm I'm sure.

In the field it should but all sorts of factors can limit depth I guess.

 

[Twapster]

Had a play with the xterra 705 with the gold coil yesterday afternoon. I could pick up a .08 gram picker from 3cm away. The sensitivity was on 20, iron discrimination on 5 and the automatic ground balance turned on.
Greg

That's not bad on a tiny piece Greg. Id be interested to see how she pings a .5g+ nugget. I've got no idea how different the 70 and 705 models are in terms of depth. I guess the biggest problem is having nuggets "lying around" to test with! Wish I had more.

 

[Twapster]

Ok some more results:

F1A4 on a 100gram gold bar 20.5cm (no headphones)

With Johns machine:

Model: Garret AT Pro International / VLF
nugget Weight - .5g / .87g / 100g gold bar
mode: Pro Custom, Max sensitivity
coil size: Nel Sharpshooter 10" by 5.5"
accuracy level: ruler with gold stuck to blue tack (ruler method)
depth: 7cmcm / 12.5cm / 24cm

 

[condor22]

Before I found my first gold, I got a variety of lead sinkers and weighed them. I also flattened to some extent, the smaller bits.
I had 0.2gr, 0.6gr, 2.2gr, 3.6gr, 1/2oz and 1oz, wrapped in a bit of masking tape for a label with the weight written on it and put into a plastic coin bag. I have the GPX5000

I did a fair bit of air testing with all 4 coils at various settings and distances. Apart from this info it was also good practice for pinpointing. It gives a reasonable insight into the different responses ie between the 8" mono and the 18x11 mono re small and larger targets. Also did the 11" DD testing discriminate with a small washer.

My 1st piece of gold was 0.2gr and on the surface. When I got the ping I wiped my boot over the area and the signal was gone, I thought, "more rubbish" but checked it anyway. Which proves the point of checking every target. My last piece was a 0.8gr at about 3" deep, using the 11" mono with the detector set to Fine Gold and most of the settings at FP.

If the ground is noisy and I use more conservative settings, I get the sinkers out just to check what responses I get and adjust the detector to get the best compromise of quiet vs response.

 

[Twapster]

Tks for the info Condor, I always carry my .5grammer in a container and throw it down every now and then when the ground noise is confusing me! Helps keep my sanity!