Garrett AT Max Chatter

[mh9162013]

I mainly run a Minelab Vanquish 540 and search for coins and/or jewelry. So it's a rare occurrence for me to hear it sound off on iron or EMI.

I recently acquired a barely used AT Max and compared to my 540, it sounds like it's nuts, with chatter like crazy. Some of this appears to be EMI. But it also seems to be super sensitivity to faint signals, especially iron.

I used it outside for a bit and I usually needed to set the sensitivity to 2, 3 or 4 (out of eight) to stop the chatter. My understanding is that I have 3 realistic options to reduce chatter.

One, I can adjust the frequency/channel (F1-F4) and see if that helps.

Two, I can reduce the sensitivity while the machine is on. This seems to work, but I'm afraid it's killing my depth (although I don't know by how much).

Three, I can set the sensitivity to 1 and turn off the machine. Then, turn it back on and only then, adjust the sensitivity to as high as I can get away with. The higher the sensitivity is set when turning it off, the more chatter I get when I turn it on.

Are there any of things I can do to get a less fritzy machine?

Any insight or experiences will be appreciated. Most likely I'll sell either this or one my Vanquishes and right now, the AT Max is getting clobbered by the 540. But to be fair, I've used the 540 for probably 50 or so hours and the AT Max for less than 2.

[JCR]

Check the coil cable connection for snugness then do a Factory reset. This will get you a fresh base. Afterwards find a CLEAN patch of ground in Zero mode and get a good ground balance on the detector. At 6/8 sensitivity it should be stable with a good ground balance. If the ground is highly mineralized, then you may need to reduce the sensitivity more or run the Iron Disc up to around 5-10. If the EMI is bad it will false & flash VDI's with the search coil elevated, that is what the frequency shift is for. If you still have instability you may have a bad coil. To check, tap it lightly with your no jewelry hand.

[phrunt]

When I was looking into these detectors as an AT Max popped up very cheap nearby and I was considering getting it I watched this video that compared the AT Series.  The seller of the AT Max here said it's very chattery but not faulty, they'd had it checked.  They basically didn't like it but were new to detecting.

In this video the Max likely had the best depth by a little bit but it was in my opinion very unstable compared to the AT Pro and AT Gold with the chattering you're talking about.  I think it's because they've got an At Pro and cranked this thing up as high as was possible to make the AT Max on the edge of stability so running a little lower on the gain is probably not that detrimental.   If it's anything like my T2 the performance is better on 60 gain out of 99 than it is at 99.

Either way, this video is worth the watch, the AT Max does do arguably a bit better, but you have to put up with a noisy detector which I don't like.

 

 

[mh9162013]

Thank you both for the responses. I'll take them into consideration when I next tinker/use my AT Max.

[mh9162013]

1 hour ago, JCR said:

Check the coil cable connection for snugness then do a Factory reset. This will get you a fresh base. Afterwards find a CLEAN patch of ground in Zero mode and get a good ground balance on the detector. At 6/8 sensitivity it should be stable with a good ground balance. If the ground is highly mineralized, then you may need to reduce the sensitivity more or run the Iron Disc up to around 5-10. If the EMI is bad it will false & flash VDI's with the search coil elevated, that is what the frequency shift is for. If you still have instability you may have a bad coil. To check, tap it lightly with your no jewelry hand.

I checked the cable connection and did a factory reset. Still no difference.

I also tapped the coil and didn't notice any change in performance or odd sounds.

I was able to set the sensitivity at 5 and there was little to no chatter in my living room. But I had to use the "turn it on with a 1 sensitivity" trick.

It appears that, like many others with an AT Max, I don't have a faulty machine. Rather, it's just super sensitive. But in making the necessary adjustments, I'm curious as to what kind of performance I'm getting.

Like phrunt already alluded to, an AT Max on 5, 6 or 7 sensitivity might be equal to max sensitivity on the AT Pro. So running an AT Max on a 6 or 7 might give the equivalent depth ability as an AT Pro that's maxed out with its sensitivity.

Thanks again for your help.

[mh9162013]

56 minutes ago, phrunt said:

The seller of the AT Max here said it's very chattery but not faulty, they'd had it checked.  They basically didn't like it

If my AT Max can outperform my 540 in my moderately mineralized soil (I get about 70-85 readings on my AT Max when ground balancing), then I'm willing to deal with some extra noise.

Right now, I'm trying to see if "MIQ, but no GB" is better than "GB, but no MIQ."

For shallow targets, I think the AT Max might be more accurate with its VDI...at least in some instances. For example, a copper penny rang up with a range of 23-28 on my 540 and about a 73-79 on my AT Max. 

[Jeff McClendon]

On 6/7/2021 at 2:32 PM, mh9162013 said:

If my AT Max can outperform my 540 in my moderately mineralized soil (I get about 70-85 readings on my AT Max when ground balancing), then I'm willing to deal with some extra noise.

Right now, I'm trying to see if "MIQ, but no GB" is better than "GB, but no MIQ."

For shallow targets, I think the AT Max might be more accurate with its VDI...at least in some instances. For example, a copper penny rang up with a range of 23-28 on my 540 and about a 73-79 on my AT Max. 

As you have experienced, the Vanquish 540 is a very well behaved detector, gets excellent depth and has excellent target IDs even on very deep coin sized targets. Absolutely smokes it on dry and wet saltwater beaches.

As you have also experienced, the AT Max is a bit poorly behaved (but can be trained) detector that gets excellent depth (might go a little deeper than the Vanquish 540 but you won't get an ID or it will call whatever it is iron), has an outstanding, very hot All Metal mode and target IDs are good down to a depth that depends on your soil mineralization. So it is a chatterbox especially if it isn't ground balanced properly and if there is plenty of EMI. Its gain is definitely on steroids.

The AT Gold is more tame but with excellent depth. In my opinion, Garrett took the AT Gold, not the AT Pro, and cranked it way up, added a few features that are missing on the AT Gold and lowered the frequency.

[mh9162013]

46 minutes ago, Jeff McClendon said:

Its gain is definitely on steroids.

Yeah, that's the impression I'm getting. But I'm trying to quantify that concept to my conditions and in relation to the 540.

I'm hoping that there's some "rule of thumb" I can rely on. For example, an AT Max with its stock coil and 4 sensitivity might be the rough equivalent of a Vanquish 540 using a V12 coil with its sensitivity set to 8.

Based on some air testing indoors, my 540 needs to have its sensitivity set to 8 for it to be fairly quiet. There will be a blip or chirp every few seconds, but it will be faint. Even when set at 10, the 540 isn't so chattery that it can't be used, as solid targets can still be easily identified over the chatter.

In contrast, my AT Max needs to be set at 4 sensitivity to achieve relative silence that's on par with the 540 at 8 sensitivity. However, when on max sensitivity, the AT Max is totally unusable. Also, when at a 4 sensitivity, its air test range is probably about 1/6 to 1/4 less than the 540 on 8 sensitivity.

I know this is just a basic test, but I'll see how real world testing seems to compare between the two, both in soil and tot lot conditions (my tot lots have wood chips, ground up tires or sand which are almost like doing air tests, at least with my 540)

[mh9162013]

Update:

I used the AT Max at a local tot lot and it did just fine in sand. I was also able to bump up the sensitivity to 6 with the machine still being usable (for finding dimes, pennies and quarters) and 7 worked too, although was a bit chatty and somewhat usable.

At a tot lot, it's definitely not as quiet as my 540, but seems to perform as well in terms of being able to find the same coins (except nickels). I think it'll struggle more if I'm looking for jewelry or nickels. Might need to keep the sensitivity around a 1 or 2 instead of a 2 or 3. I look forward to doing more testing in the future.

[67GTA]

They will both find about the same as far as coins/relics. Where the multi-IQ shines is with small jewelry and low conductors such as foil/nickels. The Max will give a more scratchy signal and targets can be easily walked over because they can get lost in with the chatter. As you probably already know, multi will still give you clear signals even down to 1.