The Legend In Minerals & Tone Options

[JCR]

The Legend was my first SMF detector, and it has really impressed me with it's performance, especially on my mineralized relic sites. These are red dirt sites that I had worked over hard with Single frequency machines, to the point of seeming worked out. The Legend made them seem like new again. Now, 2 years later, the same sites seemed to be getting thin again. A second, different SMF detector, the Rutus Versa has shown that there were still good targets to be found. These have mostly all been small to very small, but a few larger surprises. It is amazing to me how different machines "see" targets/ground & report in their own way.  This tells me there is no ONE BEST detector, and a site is never completely worked out. This is a good thing to me, because I like fooling around with detectors and learning what works & why.

 I have been experimenting on & off with ways to make the Legend perform better on smaller coin size targets in my red dirt minerals. One that shows promise is taking advantage of the Legend's adjustability to set up a special 4 tone audio profile. This profile is to capitalize on the fact that the Legend actually sees a smaller/deeper target in my mineralized soil, it just sees it, and calls it as a Ground response of TID 1.  The special audio profile puts TID 1 in the first tone bin by itself, with a medium high pitched tone. The second tone bin is for iron, with the normal low tone & breaks at 7. The third tone bin is a normal mid tone, and the fourth the normal high tone.  This works quite well, at least on my test bed. I have had some success with it in the field but need to do more hunting with it.

 What I really think @Nokta Detectorsshould consider is adding a Hot Rock control to the Legend. The Rutus Versa has this feature, and it makes a big difference in bringing out non ferrous targets that are being swallowed up by the Ground mineral response.  By adding a positive adjustment, the TID scale is shifted slightly to bring targets back around to a non ground/non Iron TID/Tone.  I demonstrated this in the first video I posted several weeks ago on my channel Red Dirt Detecting.

 Here is a video of the Legend, running thru the same test as the Versa previously. Please forgive the crudeness of my second only video attempt. I will try to improve in future.

 

[HardPack]

13 hours ago, JCR said:

Ground response of TID 1

The site I am detecting is a slope with a contact separating an upper basalt formation from a down slope slate formation. Erosion has carried the basalt sediments down slope along with quartz from the contact over the upslope portion of the slate formation. With the Legend basalt hot rocks consistently hit TID 1 with an occasional roll over to 60. The problem Is small gold on the surface will hit TID 4 or 5 then even lower depending on depth. With ground discrimination the basalt hot rocks are eliminated along with the possibility of smaller gold targets. There is no problem detecting 22 caliber or larger lead or brass casings. Been able to deal with ground noise with both ground balancing and lower sensitivity adjustment but in All Metal Discrimination the basalt hot rocks remain.  I’ll try lifting the coil over TID 1 targets as you suggest plus dig all targets until I am satisfied there’s no hidden small gold. Thanks for the demo.

[JCR]

@HardPack,   Lifting the coil should help on the hot rocks.  I would recommend testing to see what level of sensitivity/depth loss it costs you on the type/size targets you are wanting to find.  Trying to Ground Balance to the hot rocks if possible would help also, or even running a GB manual offset.  Again, test to find what the trade off may be.  Basalt would be a pretty tough environment. I’m thinking your ground conditions and mine are on on opposite ends of the scale. My TID 1 tone setup may not be practical for your conditions. You will just have to experiment.  I’m kind of outside the conventional box getting into the weeds on the video. I hope it was thought provoking at least and maybe helpful to some.

[Jeff McClendon]

Hi JCR,

Thanks for the great video and for the excellent information. Your video iss way better than the ones I make for sure!

What iron filter settings were you using?

[JCR]

Thanks Jeff.  Iron Filter/Stability was at 1/3.  V1.11 performs the same. The LG35 coil will perform better.

[HardPack]

19 hours ago, JCR said:

Lifting the coil should help on the hot rocks

Been detecting the claim with the Legend in goldfield multi, sensitivity 15/16. In the test garden the soil is different from the claim but similar ground balance numbers. In the test garden I was able to hear a faint threshold break on an 8 inch deep 30 caliber lead ball. Today I used a 56 kHz single frequency VLF detector in All Metal on the claim to double check. The TID range is 0 to 99 so the hot rocks were hitting TID 3/4. Picked up the same targets ranging from 22/40 caliber lead, lead pellets & boot tacks. Both detectors are actually smoother at mid range sensitivity settings. I think lifting the coil is a good option, if in doubt dig.

However, per the ML EQX 900 manual…search modes… the Multi IQ processes a lower or higher weighted multi-frequency while “ground balancing for soil”. Assuming the Legend also uses the remaining SMF for “ground balancing the soil” this may identify the missing small target problem. There might be a trade off where small targets are ground balanced out as a part of the mineralized soil. Could Recovery speed, even on low iron trash sites, be a solution? 

[JCR]

My understanding of Recovery speed/Reactivity is that it is actually a Ground Filter. It functions by adjusting the detectors response to how quickly it reacts to changes in the receiver's field.  Mild ground's signal response changes slowly, so you can use less filtering. Highly mineralized ground changes more rapidly & requires more filtering for stable operation.  How this same Recovery/Reaction control also effects actual target separation may or may not be be incidental or intended. Someone like @Geotechwould have to explain it for me.    What I do know is that in my experimenting with the Legend and my other detectors that have this control, it makes a noticeable difference in having it set to match the Ground.   More so than trying to separate closely spaced targets. The deeper the target and/or the worse the ground, the more important.   The difference on the Legend is not as pronounced as on say the Rutus Versa.  Each detector seems to have it's own sweet spot on sweep speed vs Recovery setting. At some point you can out swing a low Recovery setting.  On the flip side, you can shorten audio response or limit detection depth with a fast Recovery setting to the point of over running good targets & never hearing them. You really just have to spend time experimenting with all this if you want to understand the detector at these kind of levels. For the Legend, in that days test bed conditions, Recovery 6 seemed to give the best response. 4 was not quite as good, nor was 8. 5&7 were pretty close to the same as 6.  On my similar field sites I usually just go with Recovery 6 for non busy areas and listen closely for targets & changes in the ground signal by using NO Disc at all.  Higher than Recovery 7 really cuts the audio response for me and kills depth sharply.

 As far as Ground balancing, my understanding is that a SMF detector typically uses a low frequency out of the simultaneous group to balance to & monitor the Ground response.  Since a good effective GB is made on a target free spot, any subsequent change, whether from changing ground minerals or an actual target will give an audio indication.  I think that what I was trying to demonstrate in the above video is an example of this.  The small targets are being masked by the larger Ground signal to the point of being identified by the Legend as a ground response of TID1. In order to notice this, a good accurate GB needs to be maintained.   My suggestion to @Nokta Detectors of adding a Hot Rock control would mitigate this effect by adjusting the detectors internal phase scaling.

 Sounds like your making good progress on you mining camp site.  I have a few Hot Rocks but nothing like you are dealing with.

 

[HardPack]

3 hours ago, JCR said:

My suggestion to @Nokta Detectors of adding a Hot Rock control would mitigate this effect by adjusting the detectors internal phase scaling.

I agree, JCR you’re really putting the head on the pin. Nokta should be out with a firmware update this spring. I have the LG24 on the Legend recovery was at 3. In the test garden I have a clean area for ground balancing which is 42. In goldfield keeping the sensitivity at 16 and recovery set at 6, I was able get a good clean threshold tone change on all 7” and 8” targets with no TID number for any target. With the LG24 at 5” (and probably even 6”) TID for all targets. The photo is of the test garden’s granitic clay soil for comparison to your red dirt. Target sequence penny, nickel, dime, quarter & 30 caliber lead with depth 4”, 5”, 7” & 8”.

The claim’s mineralized soil ground balances in the 50’s, the basalt hot rock TID is 1 rolling into 60, targets depth is not controlled and varies so often produces a TID but all are suppressed by the mineralized soil very similar to your video. Shallow small gold targets are going to be in that TID 1 to 3 range. I have access to another site with plenty of exposed bedrock. You may be spot on with recovery 6. Thanks