So What Is Gold Mode Exactly?

[Steve Herschbach]

Nuggets found using Gold Mode, MF (multifrequency). Largest 9.8 grains, two smaller 0.6 grains each. Full report here.

 

OK, there has been a lot of speculation on Gold Mode, and with Equinox shipping out in the next couple weeks I can now offer the basics.

Gold Mode is designed to help optimise the finding of very small items. That normally means small gold to most people, so it has been called Gold Mode.

A question that has been asked a lot. Is Gold Mode a true threshold based all metal mode? Not as I would define it. 

On many VLF detectors a true, raw, unfiltered response can be seen via some pinpoint modes. All metal non-motion response.

Next would be a motion based "first derivative" all metal mode, that basically adds motion filtering to the raw pinpoint signal in an attempt to keep an even threshold while in motion. This mode has no discrimination capability at all and just signals targets. This is the classic "true" all metal mode used on early induction balance prospecting detectors. Next would be "second derivative" filtering that is the classic motion based discrimination we see on most detectors today.

Then along came dual channel processing. Many detectors started layering a visual discrimination channel onto the all metal channel, creating detectors like the that have a visual target id while in audio all metal mode. The X-Terra also has what is called "Iron Mask" while in Prospect Mode, which apparently incorporates a ferrous reject into the channel or employs a layered parallel channel. I don't know the technicalities, just that the feature is there.

Are these "true" all metal modes? Not by old school definitions. And so to me at least Gold Mode does not fit that particular definition. The threshold, while it exists, responds more to items that are nulling on masked items (which may include ground and some hot rocks) than to ground variations in the classic sense as would be expected of a pure all metal mode. However, the extra capability offered sure does not have me pining for a true threshold based all metal mode.

Gold Mode can run at MF (multifrequency), or 20 kHz or 40 khz. It does fit the definition of being an all metal mode by not being able to employ target tone identifications as is available in all other modes. You have a single tone, but it is adjustable for pitch. You do however have full time on screen target id numbers displayed at all times so you do have visual discrimination ability, but Gold Mode goes one more step, and you can also block/mask/notch just like you can in other modes. This is particularly important for the very low numbers down around -9 and -8 as some ground and hot rock responses roll in around there. Blocking low end ground responses causes the threshold to null (assuming you have it set loud enough to hear it) and so the nulling effects can alert you to ground changes and a possible need to tweak the ground balance if you are running in manual.

However, what makes Gold Mode different in my mind is the processing, and in particular the audio, which employs a VCO based boosted audio that conveys the target in a way that gives a fuller picture of target intensity. The other modes have the standard Minelab modulated "beep" that simply gets weaker or stronger depending on the size and depth of target. The Gold Mode VCO based "rising/falling" response is more akin to what is seen in machines that produce that "zippy" response on tiny targets.

The bottom line is Gold Mode can provide stronger audio responses on tiny targets. The large coil is fighting this a bit as a smaller coil or an elliptical will provide even tighter, zippier responses.

The Gold Mode is not an automatic magical solution; it is simply a mode processed in a different way that can be advantageous in some situations and not in others. I expect given how some of us are very particular about how machines sound and act that this will be a mode some people really love and others might hate. VCO tends to have that effect on people.

To sum up, Gold Mode is optimized for tiny targets, the most obvious way being with a boosted VCO type response on tiny targets, but there may be more to it than that I am unaware of. It does have both volume and threshold controls and while it is monotone the pitch can be varied. There is full time on screen (LCD) target id information as will as the ability to individually mask responses, mostly intended for hot ground/hot rock/ferrous responses but it may be used on non-ferrous targets also.

Anyway, for those who think this is a key issue for them between Equinox 600 and Equinox 800 I wanted to try and clarify this a bit while people are still in pre-order mode in case people want to rethink things. To me the Equinox 800 is something I have to have based on the audio and other advanced tuning options, and Gold Mode is just an excellent bonus. in other words, I would still get the Equinox 800 even if Gold Mode did not exist. That's just me however and for others that lean differently hopefully this helps you out.

https://www.detectorprospector.com/forums/topic/7468-my-tips-on-nugget-detecting-with-the-minelab-equinox/

 

[InTrouble]

Thank you for the well thought out explanation Steve. As I have found in the last while as a member new to this game, you have a way of cutting out the chaff and getting to the nitty gritty of the issue. I have learned a great deal more from your posts, not just about the Equ  but on the subject of metal detecting itself, than from just about anywhere else I have tried to find info on the subject. Thanks for the great explanations and keep up the good work....

[Steve Herschbach]

Well, just to be very clear - I do not know the technical details of how Gold Mode is doing what it does. I may have went astray in mentioning all metal modes and attempting to define them. That is not what is important to me or what I was trying to convey. I was just trying to describe what Gold Mode acts like, nothing more. For me the big difference in Gold Mode is the way the audio gets processed. There may be far more to it than that from a technical perspective. I am just trying to describe the difference from an end user perspective. The only reason I mention the classic threshold based all metal mode is that it provides a frame of reference for the old-timers in the game.

[Jonathan Porter]

Steve I think you've done a stand up job and it is definitely food for thought at this early stage. From my perspective (Gold Prospecting-centric) I'm no longer trying to get max depth from this type of detector so just do not focus heavily on deeper sounding responses, I have an SDC and GPZ for that type of detecting. With that restraint removed I'm then freed up to focus on what the Equinox is truly good at, ping little nuggets in quieter soils with real time data on target probability. 

To me the EQ brings me into a whole new world of information not previously available in a decent auto Ground balancing VLF gold machine, I am now, whilst prospecting, able to tap into some of the features I love so much on the top end dedicated coin and relic machines, and whats even more impressive, I can take that exact same detector and go chase coins and relics if I want to, no re-familiarization process just change modes and away you go, brilliant! 

A really good read and food for thought as we all patiently wait for the Equinox.

JP

[Steve Herschbach]

Thank you JP for all you do and the kind words. I am like you in that I am used to running a GPZ day in and day out and so when I switch to VLF my concern for depth is not paramount. If it was I would keep swinging the GPZ. It's not that VLF depth is not important, but when talking prospecting detectors and VLFs it always has to be stated "great depth - for a VLF". I don't want people thinking that a $900 VLF somehow changed the rules versus the big gun prospecting detectors. Just like the Aussies that thought the Gold Monster was going to outperform the SDC 2300 on hot Oz ground. I would like to try and keep this all as real as possible.

[Mountain Mike]

As a long time coin and relic hunter with no prospecting experience. I am really looking forward to this new machine as it will give me a new excuse to make some road trips and search for gold. So what is the TID range for raw gold? Or is that still  being tweaked? 

[Steve Herschbach]

Raw small gold typically gives low target id numbers, single digits, but you have to incorporate personal experience on your ground when relying on such things as gold nugget will read anywhere from foil to aluminum can. Here is a thread that details the subject. When in doubt - dig it out!

[Jonathan Porter]

3 minutes ago, Mountain Mike said:

As a long time coin and relic hunter with no prospecting experience. I am really looking forward to this new machine as it will give me a new excuse to make some road trips and search for gold. So what is the TID range for raw gold? Or is that still  being tweaked? 

Depends on the level of mineralisation. When hunting gold you have to look at discrimination differently, it becomes part of your tool set in combination with a lot of other things like, swing speed, coil height, audio response (a very important one that one) ground type etc. I use all metal almost exclusively, if that helps.

JP

[Mark Gillespie]

I have desired and conveyed a particular want in a motion all machine for years.  It is simply an audio option of at least two different tones.  One for iron, the other for non ferrous targets in a VLF machine.  Is that to much to have asked for?

I had one of the guys at 1st Texas reply with a similar statement, "it's easier said than done" 

[Steve Herschbach]

OK, after a little more study, I have decided to create a new term - "trailing VCO audio". Park, Field, and Beach mode employ a more or less standard Minelab "beep". The sound is modulated so small or deep targets produce a weaker "beep".

Gold Mode employs trailing VCO audio. The response ramps up almost instantly on strong targets and then trails off. Weak signals have a soft response, strong targets a higher pitch louder response. The difference is that in traditional VCO response the target ramps up and trails off in a more even/equal fashion on both weak and strong targets. On Equinox the weak targets have a softer response that is more like traditional VCO but the strong targets ramp up instantly and then taper off.

Hard to describe but this short video should make it obvious. Standard 35MB mp4 video that needs to download and play locally.

This was shot in my basement so the sensitivity is down at 10 to eliminate noise from electrical, surrounding junk, rebar in floor, etc. The only intent here is to try and show the audio difference so please don't read anything more into it than that.

Park Mode first, then Gold Mode, then Park Mode again....

herschbach-eqx800-audio-park-vs-gold-mode.mp4