Effect Of Black Sand On The AT Pro? Brent Weaver's Answer:

[John-Edmonton]

Brent Weaver is the engineer behind the AT PRO. I thought this might be of interest so I pulled this off the Friendly Metal Detecting Forum:

[color=#009933[size=large]"Mineralized black-sands are a challenge for any detector. However, the AT Pro performs quite well in these conditions for the following reasons:

- The DD coil design significantly reduces the negative effects of ground minerals.

- The ground balancing function also significantly reduces the performance-robbing effects of ground minerals.

- The internal filtering and signal processing are designed to address highly mineralized environments."[/color]



Brent

 

[bearkat4160]

Kool I like it! Not much time to wait now!

He also had a hand in the design of the Infinium...hopefully hes working on some additional improvements on it for the prospector...!

Alan

 

[John-Edmonton]

He has an excellent reputation from the people who I have spoken to who know him.

 

[Uncle Willy]

Yeah I mentioned those points awhile back when the question was posed plus Charlie Weaver had tested it in the black sand in Idaho on the Snake River and it performed just fine.

Bill.

 

[Uncle Willy]

He ain't a bad engineer either. HAA.

Bill

 

[SteveP(NH)]

I'm not sure what the context of the question he was answering was, gold field hunting or beach hunting, but the problem isn't black sand all by itself, it is black sand and salt water wetted sand mixed together, and the problem that the concentration of black sand and salt changes very rapidly over short distances. Black sand and salt have very different ground balance settings and when you have the two mixed together you can't just take an average reading with the vlf detectors I have used thus far. Plus at the beaches I hunt at the black sand (its really very dark purple here) is heavier than the white sand and so it concentrates where the wave action is the heaviest as the white sand gets washed away there. Plus when you are down in the salt water wetted sand each step you take towards the ocean has a different ground balance value than a step farther away from it. You need to at the least have some sort of ground tracking system to keep up with the changing ground balance values to have a chance but using VLF machines with ground tracking such as the GTI-1500 fitted with the 10x14 shoulder breaker DD. or a Minelab Xterra 705 (which even has a salt water beach mode) fitted with the 18KHZ DD coil can't keep up with the multi-frequency machines. Although I don't have any experience in the gold fields I understand that the black sand concentration can vary over short distances there as well.

I am sure the AT Pro will be a great relic machine for use at inland locations but is it a wise idea to promote it for uses which it might not be suited for? A customer who buys one for salt water beach use, before we have real reports about how it does at salt water/black sand beaches based on posts like this, may be getting set up for a major disappointment and then disillusionment with Garrett detectors. Remember a lot of newbies lurk on the forums and don't have any experience on which to evaluate reports like this. I am sure it will do as well a,s if not better than. other VLF machines that don't have ground tracking but that still doesn't make it a first choice for a purpose for which it wasn't designed.

 

[Frank in NH]

n/t

 

[John LA]

n/t

 

[metalhead]

I use my LS or MKll in the salt water/black sand beaches. They work like a charm and get great depth. If you want a machine that works great in those conditions, get a P.I.
As far as VLF machines go, of course the multi-frequency units run smoothest in these conditions, but don't get the depth of a P.I. and have better disc than P.I.
Yeah, you can use a manual ground balance single freq VLF and just balance on the fly. Kind of a hasle, but still fun on the ocean beach. I'm sure that the Pro will work alright in these conditions.
I'm just glad that Garrett's finally came out with a new VLF wader, which I'll use mainly for fresh water hunting. I've been waitin' on this for years and the freq is perfect for gold. Happy Hunting!

 

[EZrider]

Some VLF detectors out there have a "Beach" or "Salt" mode that you switch to so you can ground balance. The reason is that ground balancing in the dirt or freshwater is diff rent than the wet salt sand. These salt switches worked to a point on calming the machines down. The Scarface was the loss of depth.

The AT will work in the salt "some places" and people will make finds with it no doubt. There are some places that even the best multi freq machines have a hard time at. I think the AT is really going to shine in the Fresh water!! One good find and its payed for.

 

[SteveP(NH)]

I use my LS or MKll in the salt water/black sand beaches. They work like a charm and get great depth. If you want a machine that works great in those conditions, get a P.I.
As far as VLF machines go, of course the multi-frequency units run smoothest in these conditions, but don't get the depth of a P.I. and have better disc than P.I.
Yeah, you can use a manual ground balance single freq VLF and just balance on the fly. Kind of a hasle, but still fun on the ocean beach. I'm sure that the Pro will work alright in these conditions.
I'm just glad that Garrett's finally came out with a new VLF wader, which I'll use mainly for fresh water hunting. I've been waitin' on this for years and the freq is perfect for gold. Happy Hunting!

I use a multi-frequency unit with ground tracking. The PI units do go much deeper but there is just so much trash on these heavily used beaches so I prefer the discrimination and target ID capabilities of the multi-frequency VLF units.

However I do prefer to use single frequency units for relic hunting as the are lighter and go just as deep. That is why I have pre-ordered an AT Pro, I would not be surprised if it gives my Fisher F75 a run for its money but I think that is largely going to come down to which unit has the faster recovery speed. Haven't heard much about that on the AT Pro but Garrett has used its recovery speed as a point in its marketing materials so I trust it will be a fast machine.