Single Frequency Vs Smf Gold Prospecting Detectors

[Jeff McClendon]

I see this question at least once every 3 months on this forum.

It goes something like this...." Are dedicated single frequency gold prospecting detectors better than the latest do everything simultaneous multi frequency detectors for gold prospecting?"

Maybe this bit of semi-real world testing will help some people.

I wish I had a wider selection of dedicated gold prospecting detectors, especially a Garrett/Whites Gold Master 24K and a Fisher GoldBug 2. I don't. I do have a Gold Monster 1000 (for a little while) and an XP ORX with 9.5 X 5" HF coil and its great gold prospecting modes that even have a live threshold.

So I tested those two detectors and used the XP ORX in 15.8 kHz to simulate several great 13 to 18 kHz detectors that have been used for gold prospecting including the Whites MXT, Fisher F75 and the Garrett AT Gold. I used the Nokta Legend in 20 kHz to simulate several 19 to 20 kHz detectors like the First Texas Gold Bug/F19/G2+/Time Ranger Pro series and the Nokta Multi Kruzer and Anfibio. I also used the Legend in 40 kHz, XP Deus 2 in Mono 45 kHz and the XP ORX in 74 kHz. 

The XP Deus 2 and Nokta Legend were also tested using their simultaneous multi frequency gold prospecting modes. I consider the Equinox 800 and Legend to have almost identical gold prospecting performance. Equinox 900 is slightly better from my experience and Manticore with its 8" coil appears to be even better.

So, XP ORX with HF 9.5X5" elliptical coil, GM 1000 with 10X5" elliptical coil, XP Deus 2 with 9" round coil and Nokta Legend with 9.5X5" LG24 coil. I used the Nokta Legend stock headphones with wired connections for all detectors so that there would not be any variations in sound quality.

All detectors were noise canceled, ground balanced (the Gold Monster used has the updated Quick Track) and all were used in 1 tone VCO audio with absolutely no target IDs rejected. Deus 2 45 kHz Mono was set on -6.4 discrimination.

EMI was a problem so the single frequency detectors and selectable single frequency detectors were able to run higher sensitivity than the Legend using its SMF so keep that in mind when viewing the results. Plus I made a mistake recording the settings in the results below. The Legend using SMF Goldfield Multi had sensitivity on 23 of 30 not 25 as reported. It was fairly quiet at that 23 setting. I had to run Deus 2's SMF Goldfield at 95 just to compete and it was EMI noisy. I tried to run this test with the Manticore but I only had the stock 11" coil and EMI was unbearable.

I used a 0.05 gram nugget and a 0.15 gram nugget under 1" of moderately to highly iron mineralized Arizona gold field dirt. This dirt's magnetite mineralization almost filled up both the ORX and Deus 2 iron mineralization meters. 

I used a 0.25 gram nugget under 3" of the same dirt.

I used a 5 gram USA modern nickel under 4" of the same dirt

Any depths reported beyond those were "air gap" depths swinging the coils a few to several inches above the top surface of the dirt.

 

 

 

Here are the results:

 

I wish I could have done this testing outdoors in the gold fields. Weather is definitely preventing that here in Colorado.

Thanks for looking.

[JCR]

A very informative test.

I don’t have the opportunity to nugget hunt but even so, SMF detectors opened up a whole new level of detection in difficult soils for me. Their ability to run smooth & stable in the worst mineralized ground, with Iron trash to boot is still a wonder to me. I still have & use my older Single frequency units for certain scenarios & also just for fun, but SMF is the way to go most of the time.

EMI has never really caused me a lot of problem. Lowered sensitivity still gets most jobs done if need be. I will usually lower Audio Gain first, then lower Recovery speed if practical.  The Legend’s default AG is 1 in Gold Field, I assume that is what you were running.

Hope you can get out of the house soon.

[Jeff McClendon]

2 hours ago, JCR said:

 The Legend’s default AG is 1 in Gold Field, I assume that is what you were running.

Actually, I was using Audio Gain on 3 in Gold Field for the Legend. I like the updated threshold tone to just barely be audible using the stock Legend BT headphones. Leaving Audio Gain on 1, it is easy for my ears to lose the really weak responses. AG 3 lifts them out of the threshold tone nicely for me.

I use an Audio Response setting of 3 or 4 with Deus 2 FMF Goldfield for the same reason.

I wasn't sure how this testing would turn out. I had my suspicions but your assessment of these SMF/selectable single frequency detectors running in hot dirt using their multi frequency modes has been similar to mine. I really expected the ORX and Goldmonster 1000 to dominate on the smaller stuff. They didn't and especially the Legend, which for me is an upgraded Equinox 800, really stayed right with them and even beat them.

[JCR]

It really is amazing how sensitive the Legend is to very small targets, no matters what coil. I actually seldom run in M2 because it will have me digging too much tiny stuff. A .22 Short slug is small enough for me. JFYI, the Rutus Versa in Multi F Low conductor will see even smaller targets than the Legend. Maybe @EL NINO77can give an opinion on it’s nugget hunting potential.

[EL NINO77]

VERSA in Multifrequency low conductor even in dynamic mode is really sensitive to small targets - the photo shows what I dig when I focus on detecting targets with low VDI 6-11...

 VERSA  program Park -  Multi F low conductor

------------------------------------------------------------------------------------------

VERSA  Program Park 1 F- 40 khz

 

VERSA 1F 40khz

[Jeff McClendon]

I am very partial to anything from Poland after spending a lot of time there in the late 1970s. Owning a Rutus detector could be a possibility. 

However, I prefer to do detector gold prospecting with detectors with at least a dedicated gold prospecting mode. Rutus Versa does not have one from the time I spent looking through the manual.

For me anyway, an SMF VLF detector needs to be able to easily hit a 0.01 gram or a bit smaller target through 1" of iron mineralized dirt in order for it to compete with the Equinox 800/900/Manticore/Legend.

None of the targets in your photos show anything that size and I have not heard any reports of the Versa being deliberately set up for detecting sub 0.1 gram targets.

[EL NINO77]

Jeff ..Rutus detectors have a very smooth True all metal mode...in multi-frequency mode..Dual mode .,,.,,,,, so it is not a problem to hit the finest targets,,,

in the pictures, I only document what VERSA is capable of on multi-frequency, if you focus on selective ...detection of targets from ID 7-11 from among iron...on an old stone road...
..
On my test field, I have a gold 0.05 gram gold segment buried at a depth of 10 cm in a low mineralized subsoil...
if the detector can hit this target...in discrimination mode, it is a powerful detector..

 Target /N.2/0.05 gram Gold in 10 cm depth .. on my test field...

______________________________________________________________________________________________________

 Rutus ATREX  ...

Rutus *Atrex on multi-frequency program Coin
the first target is 0.05 grams of gold, at a depth of 10 cm /marked yellow/
the second target ... is 50 euro cents per 37 cm,/ not marked/
the third target is a copy /0.19 grams of lead/ of a very small 5 mm coin 1/24/stater at a depth of 11 cm../marked Red/

 

[HardPack]

The results of the Legend in Goldfield M plus hitting a nickel at 10 inches with the LG24 is encouraging.  A lot to think about in the results. Thanks for the effort.

[Off Grid]

Jeff

Thanks these comparisons. I know Steve and others have cautioned about comparitive tests in the past, and with good reason, but some data is always better then no data.

I recall you had good things to say about the Legend some time back so I've decided to get one to back up (or take over from) my trusty GB2 that at 71 kHz probably has left stuff in the ground in my patches. 

One question. What is the makeup of the AZ dirt that you used? It looks like weathered granite wash to me. If you were to run a fridge magnet over it what percentage of magnetics would you get? Other stuff?? I was thinking of trying to replicate it, see if I get your results, run the GB2 over it and then add to your data. Be a while, mid-year or so. Of course there's probably someone down the street from you with a GB2 already 🙂.`

[Jeff McClendon]

5 hours ago, Off Grid said:

Jeff

Thanks these comparisons. I know Steve and others have cautioned about comparitive tests in the past, and with good reason, but some data is always better then no data.

I recall you had good things to say about the Legend some time back so I've decided to get one to back up (or take over from) my trusty GB2 that at 71 kHz probably has left stuff in the ground in my patches. 

One question. What is the makeup of the AZ dirt that you used? It looks like weathered granite wash to me. If you were to run a fridge magnet over it what percentage of magnetics would you get? Other stuff?? I was thinking of trying to replicate it, see if I get your results, run the GB2 over it and then add to your data. Be a while, mid-year or so. Of course there's probably someone down the street from you with a GB2 already 🙂.`

Granite is in the area of that dirt sample but most of the sample is basalt, rhyolite, andesite, caliche, tuft, sandstone and schist. When I brush a magnet over the surface it gets covered almost immediately with ferro magnetic material including magnetite.

The reason I have good things to say about the Legend is clearly shown in this comparison. The Legend does exactly what its engineers and marketing department says it does. The fact that it easily competes with the Minelab Gold Monster 1000 and the XP ORX in this comparison and from my experience using them all in the goldfields I visit speaks for itself and its VLF gold prospecting abilities.

The same competitive aspects happen in all of the Legend's other possible uses. It's that good.

I don't have access to a GB2.