A couple observations/tests on my Anfibio

[The Digger]

I tested the different modes on my Anfibio to see how they compare depth wise. I only used the depth measurement if it gave a target ID. Here's the results listed from best depth to least:
1. Deep
2. 4 Tone
3. 5 Tone
4. Tie between 2 Tone and 99 Tone
6. Beach Mode
7. 3 Tone
I did not test the Gen or Cache Modes. There was hardly any difference between 5 Tone, 2 Tone, and 99 Tone.
Also, much to my surprise, using the discrimination had very little affect on the depth.
Another interesting point: Setting the ID Depth to Hi gave me a target ID on the deeper coins, where the In and Lo would not.
These tests were all done in 14 KHZ.
Interesting Note: Metal detecting guru, Tennessee Sharp Shooter, likes to hunt in 3 Tone. It seems to me he is giving up a lot of depth, but maybe it works well in his soil.

 

[TheHunterGT]

What was the gain during the tests? I ask because of the change in depth from 89 to 90 in 3 tone mode. So I assume you were above 90 gain.

 

[The Digger]

Hey HunterGT.
Here's how I did it: I placed a silver dime at 6". I then found the lowest gain setting that I could not only hear the dime, but also get a target ID.
On the Deep mode, I had to go to a gain of 40.
4 Tone--Gain of 45
5 Tone--Gain of 60
2 Tone and 99 Tone--Gain of 61
Beach--Gain of 70
3 Tone Gain of 85
This was using no discrimination, although using discrimination had very little effect, if any.
I did test again using a gain of 90, and 3 Tone gave me the least depth.
I don't understand why anyone would hunt in 3 tone with the gain above 89. If you are looking for fast recovery speed, then use 3 tone up to 89.
If you go above 89, it seems to me you are simply giving up the fast recovery speed, and would be better off using one of the other modes.
I guess one other possible reason to use 3 Tone would be to simply cut down on the chatter/noise.

 

[thump7]

When I'm in trashy areas I cut the sensitivity down anyways, extra sensitivity just seems to make a trash hunt that much more unbearable. I expect Nokta upped/ lowered the recovery speed and used the gain @ 89 break-point for this reason.

 

[TheHunterGT]

Yeah, for sure. I often use 70-80 gain no problem in the other modes. Still goes plenty deep. If I want the "faster" recovery...89 gain (in 3-tone mode) does the trick for sure. I just hunted a very trashy section of a 120-year-old park that has square nails from yesteryear and caps and tabs from yesterday.

89 gain (in 3-tone mode) made the coins signals really stand out. Switch up to 90 and they basically clipped out or disappeared from the separation not taking place. It seems similar to FA process on a F75 or D0 on an Omega 8500.

However, going from 89 to 90 gives me a good 2 inches of depth (in cleaner areas) before it gets scratchy and ID starts wavering. For me personally...that answers the "why" of it (for the depth guys not seeking ID clarity).

I think the test you are doing is interesting for ID purposes...really neat actually.

For pure depth...2-tone mode beats out 3-4-5 on my Anfibio by a good inch. California 5-6 bar dirt on the T2 and F75...so fairly nasty stuff. I think Calabash Digger was saying 2-tone seem deepest for him as well.

At "above 90" gain settings I don't see much difference in the 3-4-5 tone modes. They all read an 8-inch Merc dime as ferrous in my nasty soil...2-tone does not until 10 inches. ID is zinc range...but still a non-ferrous tone.

Obviously, that is different than the ID test you are doing. Just saying it is neat all the same. It seems one mode may work well at one thing (such as ID)....then be trumpeted in another test by another mode (pure depth based on non-ferrous signal).