Legend what are we looking for Tom???

Here is a video I did months back on deep silver in my test garden Multi VS Single...[youtu.be]

THANKS David! You are really STARTING to see some of the error. Deep target anomaly. Push that 12" Half Dollar about another 1" or 1-1/2" deeper....... and ALL should become TOO CLEAR!

What I am encountering is.......... Multi-frequency Modes will not detect a 10" deep dime..... in my Florida dirt. (((Almost..... but not quite))). Yet 4-KHz will detect a 10" deep dime..... AND my 14" deep dime.....AND, AND, AND....with quite good ID.
In your case...... if you push your Half Dollar about an inch deeper. , . , . , . , . , . , Multi-Freq Modes will ID the Half Dollar as 'iron'; yet, 4-KHz will still detect the Half Dollar with nearly perfect ID. . . . AND quite a bit of coil air-gap above the ground! PLAY WITH THAT AIR-GAP whilst in 4-KHz!!!!!

Dilek probably thinks that I am trying to 'beat-up' on her; yet, it is exactly the contrary! Nokta/Makro has come a LONG way .... in order to detect a 14" deep dime!!!!.......but can only be detected/performed in 4-KHz. The Multi (SMF) Modes have a fundamental error in the way they are demodulated/processed.

THANKS for the video.

Thanks for the video. I hope an update is coming.

NASA-Tom Wrote:
-------------------------------------------------------
> The Multi (SMF) Modes have a fundamental error in the way they are demodulated/processed.

Maybe, maybe not. One thing about MF (any and all) is that it splits the transmit power amongst the transmitted frequencies. So, ferinstance, if you transmitted at 4 & 20 kHz it would never go as deep on big silver than 4kHz-only, and would never go as deep on small gold as 20kHz-only.

If Nokta followed the Equinox MF frequencies (and I think they did) then they are using 7.8kHz and 39kHz*, not 4kHz, so the higher low frequency takes away even more depth. So what you see may be perfectly reasonable.

It would be interesting to see how the Equinox compares since it has comparable modes.

* The Equinox also has a 2.6kHz component but it's pretty weak and I believe is used for ground analysis.

Geotech Wrote:
-------------------------------------------------------
> Maybe, maybe not. One thing about MF (any and all)
> is that it splits the transmit power amongst the t
> ransmitted frequencies. So, ferinstance, if you tr
> ansmitted at 4 & 20 kHz it would never go as deep
> on big silver than 4kHz-only, and would never go a
> s deep on small gold as 20kHz-only.
>
> If Nokta followed the Equinox MF frequencies (and
> I think they did) then they are using 7.8kHz and 3
> 9kHz*, not 4kHz, so the higher low frequency takes
> away even more depth. So what you see may be perfe
> ctly reasonable.
>
> It would be interesting to see how the Equinox com
> pares since it has comparable modes.
>
> * The Equinox also has a 2.6kHz component but it's
> pretty weak and I believe is used for ground analy
> sis.


Great stuff.
As always, thanks.

Thanks Carl !!!

I incur the problem with (small) clad dimes....... AND with larger silver coins.
M1, M2, M3 detects a clad dime to 9.3". Single Frequency 4-KHz detects a clad dime to 14.0"........and with respectable ID. (((Which.......by the way........is VERY serious performance........ by today's standards. ---All is not lost!---)))

BUT.............. the delta/differential between 9.3"......VS.......14.0" on a clad dime....... is TOO much of a (unacceptable) span.,.,., whilst comparing SMF to single-Freq.

I would be very curious to see the results for the same test on the Equinox.

I agree the differential between MF and SF are drastic, but at the same time if the Legend can detect a dime at 14.0" with usable TID, that in itself is quite impressive with the potential to open some deep silver sites up. The challenge I've found using 4 KHz (on the EQX800) is that it's not resilient to EMI given all the RF that lives around that RF space.

For the record........ the EQX in SMF Park Mode-1 will also just barely ascertain a 14.0" deep dime. Again.......... there needs to be minimal EMI !!! And that goes for any detector/brand.

So Tom does 4Khz work near the salt water? When we tested the Nox it would get a 3 gram gold ring at about 12" near the water in Multi. I dont believe ive ran into anyone using the Legend here yet..... the Deus yes. So multi kind of works like WIFI where it splits 2 and 5khz? I assume one receives more of the signal than the other (s)?

Dew....... I have not run the Legend on the wet-salt beach yet. I need to get past this SMF (vs Single Freq) anomaly before proceeding any further.

Update... in a related topic on the Friendly forum someone pointed out that MF designs can go deeper in MF mode than SF mode due to the subtraction method used to implement ground balance and salt cancel. This can be true (depending on the design and how DSP is implemented) because subtracting the reactive (ground) signals can increase headroom and allow you to run a higher gain. In SF mode you are stuck with the ground signal you have and may need to reduce gain to avoid headroom problems. So there are situations where MF can go deeper than SF on particular targets.

I wish there was more discussion on this in particular and on The Legend in general.
I am not experiencing what NASA Tom has described. I even posted about doing the comparisons mentioned.
I do not understand why The Legend seems to be an off subject. I know Tom is busy with other demands and I know some are just waiting to Bash the Legend because it is not the "ONE" for them. I have found it to be an excellent detector. I can't be the only one to think so. Am I missing some unspoken taboo?

Chris

Carl......... and this is exactly where I feel/think/speculate the problem is..... with Legend. Whilst in MF........ Ground Balance/Mineralization ..............or ---dirt VS target--- SNR is improperly subtracted.

Sounds like if it were possible, hunting wet salt beach in single low freq would be deeper than MSF?

Single-freq operation in wet-salt........ presents poor ID & poor depth.

Whenever I hear the words “ground balance”, I think of the Video that Keith S. did on the Tesoro Vaquero in which dialing back the ground balance knob 1/4 turn (negative gb) resulted in considerably more depth…I realize that the Vaquero is a single freq machine but perhaps trying a manual gb adjustment on the Legend might prove to be beneficial ?…

“There’s something happening here….what it is ain’t exactly clear “

Good question.

Monte's term, Power Balancing, doesn't seem to work on newer detectors. I turn my Tejon a lot more negative.

It works great on Tesoro's, Garrett AT series, Deeptech Vista detectors and others. Maybe the ground balance is different in these detectors than the newer ones.

Geotech Wrote:
-------------------------------------------------------
> NASA-Tom Wrote:
> --------------------------------------------------
> -----
> > The Multi (SMF) Modes have a fundamental error i
> n the way they are demodulated/processed.
>
> Maybe, maybe not. One thing about MF (any and all)
> is that it splits the transmit power amongst the t
> ransmitted frequencies. So, ferinstance, if you tr
> ansmitted at 4 & 20 kHz it would never go as deep
> on big silver than 4kHz-only, and would never go a
> s deep on small gold as 20kHz-only.
>

> If Nokta followed the Equinox MF frequencies (and
> I think they did) then they are using 7.8kHz and 3
> 9kHz*, not 4kHz, so the higher low frequency takes
> away even more depth. So what you see may be perfe
> ctly reasonable.
>
> It would be interesting to see how the Equinox com
> pares since it has comparable modes.
>
> * The Equinox also has a 2.6kHz component but it's
> pretty weak and I believe is used for ground analy
> sis.



Dear Tom,
My response would be very similar to Carl's here! There is no ''error'' in Legend in terms of the way the SMF is processsed, the results are perfectly reasonable like Carl says... and the results you are experiencing is very different than the majority of the users. In any case, please make sure you update the Legend with the new update coming. Talk to you soon!

I am looking forward to the upcoming Update for The Legend. I hope NASA Tom will re evaluate his unit and post his detailed impressions. I also wish he would build that High Mineral test bed to enable a fuller evaluation of each machine he tests. The differences between the various top end machines keep getting more subtle and we need his knowledge/experience to guide us with practical insight.

Chris

Hi Dilek,

Sure. I will gladly/certainly upload the new update.....and give it a fair shake. And I do not want you to feel 'pushed' or 'pressured' to expedite the new software release date.

Also........ With Legend: If NOT being able to detect a 10" deep dime in (specifically) Florida inert dirt whilst in Multi; yet......... able to detect a 14" deep dime whilst in a Single Frequency .,.,.,.,.......is considered: Nokta/Makro "Normal"........ then I need to recalibrate my brain to this ((new-to-me)) Nokta "Norm"......... then I apologize..... and = I STAND CORRECTED!
I'm just glad that I was able to demonstrate exactly this..... to your Nokta engineer/marketier in Melrose, Florida.......about a year ago. And then HE was ALSO able to duplicate/replicate this "Norm" for/to himself. Hence....... the Live-on-the-Wire demonstration video-chat to your Chief Design Engineer.... for his evaluation. All is well!