Air Test Of Minelab Eureka Gold With 3 Coils

[Roughwater]

Just playing with the Detector today as I was curious as to how the 3 coils I have would do in the air.  The 3 coils I have are the 10X5 stock coil, the 8" round Minelab coil and the 15" Round Coiltek WOT coil.  All coils are DD.  There are no mono coils for the Eureka.  I used the same 3 targets for all 3 coils tested at all 3 Frequencies.   The Sensitivity set to max, Threshold 3/4, Disc in all metal, Signal set to Boost and Volume max.   I used 3 different coils and only 3 targets: a 36 gn. 22 cal bullet, a 115 gn 9mm bullet and a 1899 Indian head cent.

Results are not exactly as I expected.  Used headphones for most of test but afraid phones may be interfering with WOT coil so took them off doing that test so with the low volume audio on that detector coupled with wind noise etc may have reduced slightly the depth of the Wot coil.  

 

10X5 stock coil            

 

60 Khz                     20 Khz                           6.4 Khz

 

22 bullet:     7"           22 bullet:     9":              22 bullet     8"

9 Mil bullet:  8"           9 mm bullet 9"               9 m bullet   9"

1 cent:         9"           1 cent         11"             1 cent        11"

 

8" Round Coil (All coils are DD")

 

60Khz                       20 Khz                          6.4 Khz

 

22 bullet:    9"            22 bullet        10"            22 bullet     10"

9 mil bullet  9"            9 mm Bullet   10.5"        9mm bullet  10.5"

1 cent         10.5"       1 cent            10.5"        1 cent          13"

 

15" Round WOT coil

 

60 Khz                       20Khz                           6.4 Khz

 

22 bullet         9"         22 bullet        11"           22 bullet     11"

9 mm  Bullet   12"       9 MM bullet   12.5"        9 mm bullet 14"   

1 cent             16"      1 cent           15"           1 cent         15.5"

 

 

 

[Au4Gold2]

I have fiddled with my Eureka Gold and found that its best to just keep it at 20 khz with the stock elliptical. I was never able to get use to this model so I sold it.  Found out that one could buy a much cheaper detector and get better results at nuggethunting rather than pay 1000 bucks for a Eureka. But saying that, this detector in good ground will sniff out the gold almost as good as any other vlf on the market. I did like the null out on the disc mode worked rather well....hope you do well considering you do have an assortment of coils to use on it, I just had the stock coil. Good luck on your golden quest....find some gold and adventure.

[Roughwater]

8 minutes ago, AuWanderer said:

Found out that one could buy a much cheaper detector and get better results at nuggethunting rather than pay 1000 bucks for a Eureka.

If I had to pay a grand for this detector I wouldn't be doing this test.  Fortunately I got if for less than 1/2 of a grand shipped in unused condition.  I'm thinking it will do OK.  I've heard it does well on mineralized ground though I'm not sure I'll see much of that.  I like the uniqueness of having 3 frequencies to play with.

 It was put out there all alone, looking for a home, so I raised my hand and took it in. In this land, it's not a favored one, but I'll learn it the best I can. Maybe it will pay, I'll find out one day if it will bring some gold my way.  Lord just put some yellow under her coil and make me a happy prospector, smiling, while I dig it out of the soil!

[fredmason]

Why do you think the headphones would interfere with any coil? if you let the cord get too close that would be a problem. Or if you leaned into the detection area and got the headphones too close?

fred

[Roughwater]

Hey Fred, I was concerned due to the size of the coil. I was getting the best response with moving the target past the coil in both directions which, since I was using my left hand in moving the target made be reach and put my head in or near the range of the coil.  Had I been thinking, I would have just used my right hand instead of my left which would have allowed me to be farther from the coil but it didn't occur to me at the time.  I'm kinda fussy when it comes to keeping anything that might have metal away from the coil.  I always buy the upper non metal shaft for my PI detectors and I always run the coil wire straight up the shaft leaving no turns of wire in the lower part of the shaft.  I see guys doing the air tests and setting the targets down in range of the coil and it bothers me.  I'm just funny that way.  

[fredmason]

No worries, that is correct and makes sense. Not everyone understands the true distance that an object can enter the detection field...especially iron.  being aware and careful is a good thing.

fred

[auminesweeper]

Cool Test, though like you I am a little surprized at the results I would of thought that it would have got that bullet a lot further than that, But I find that you can't run the machines that hot with the Boost running although I just did the Bullet test with the GMT and the MXT, Swinging a test piece in front of the coil will give you lesser results than bringing a test piece up the coils signal path towards the coil, Like as in from 2 feet away then up the middle of the signal path because it upsets the threshold. .

The thing that surprizes me the most is that the 6.4khz did not have more of an impact, So maybe those coils are built to favour the higher frequencies, I would of expected that 15" coil to be hitting at around 13 to 14 inches maybe,

One thing I have noticed is that Big coils add very little in the way of depth on high kHz machines and they seem to give about the same depth as the standard coil but they do give better coverage but the down side is they can only see bit the size of what a normal hot VLF can,, The best improvement for a high kHz (mid Frequency) machine is to put a concentric on it because on bits under one gram it will make the detector see it up 3 X the distance of the DD, Which might be the secrete behind the Gold Bug II, Out of all my kit that 5x9 Long Scan is my prized piece of kit.

Thanks for taking the time to test them all,

john 

[Roughwater]

Unfortunately for whatever reason they don't make a Concentric coil for the Eureka Gold.  

1 hour ago, auminesweeper said:

I would of expected that 15" coil to be hitting at around 13 to 14 inches maybe,

The 15 did hit the penny at over 15" and also the 9mm bullet at 15" in the 6.4 freq.  It may have actually done a bit better with the 15 but the wind was a factor and a darn plane happened to fly over as well right when I was trying to hear the low volume of the speaker.  

[auminesweeper]

Yeah I know what you mean, for some reason big coils on mid frequency VLFs do very little in terms of performance, but stick one on a VLF and you can gain up to 30% more depth depending on the machine / coil type, I know there is very little difference between my two apart from when it come to fine gold as in under 0.15 a gram plus or minus,

That big concentric I have can see my bare hand at about 7 inches,

john