Do they make

[rubydarlene]

As there such an animal
A detector that has a true motion all metal mode that has tones assigned to the different ID numbers?
I don't think the Etrac is in that category.
I would like something similar to the F75, motion all metal mode with tones instead of just one tone.

[Mark-VA]

I too live and hunt in the harsh red dirt of Virginia and at times the dirt is just hard to deal with but. I'll make it short. A couple years ago I contacted both Carl at Whites and Dave at 1st Texas and ask if they would be willing to test a sample of material and advise what machine or procedure would work best to hunt the areas. These areas are old school yards, well over 50's old that is. Back when they all burnt coal for heat then disposed of the coal waste on the school property. They would spread this material out over several acres. Most of the material is about the size of BB's with some larger and smaller pieces mixed in. But the bad thing about this material it easily attracts to a magnet. It robs most the signal from my machines and makes depth out of the question. Dave at 1st Texas analyzed the dirt and advised running the machine in true all metal mode was my only option with the machine I had then, but Carl being as busy as he is could not really advise the material. I can only obtain fair depth in these areas by running in all metal mode. But I have always wondered the same as you, all metal mode with just two tones. One for non-ferrous and one for ferrous.

[Waikiki_Sweep]

As there such an animal
A detector that has a true motion all metal mode that has tones assigned to the different ID numbers?
I don't think the Etrac is in that category.
I would like something similar to the F75, motion all metal mode with tones instead of just one tone.

I like Fisher CZ detectors because of multytone sound (3 or 4 tones and I am breaking inside box to make it up to 6 tones with additional resistors) and multifrequency (5 and 15 kHz) metal detecting and it is true motion and all metal mode at the same time.

[Skippy]

It might be worth looking at the Deus' user manual, it might be one of the options. The new additions in the V3 upgrade included a nugget-hunting program, not sure if that was 'delta-pitch'.
I take it the F75's delta-pitch disc mode is not what you were after?

[rubydarlene]

What I'm looking for is a machine that has tone ID attached to the motion all metal mode. The reason I need this type of machine is because in some of my hunting areas the EMI is terrible in discrimination mode so I switch to the motion all metal mode. No filters.

[Waikiki_Sweep]

What I'm looking for is a machine that has tone ID attached to the motion all metal mode. The reason I need this type of machine is because in some of my hunting areas the EMI is terrible in discrimination mode so I switch to the motion all metal mode. No filters.

If your main problem is EMI you can also to try a machine with "BIGFOOT" coil. Because in Bigfoot coil TX has a "8" shape it eliminates all EMI on 100%.
Also you can try to build your own PI detector and put "8" shape coil on it. "8" coils may reduce a depth but it has absolute EMI protection.

Also that Fisher CZ detectors I have learned schematic and can tell they have tons of filters in RX. I have never got any EMI problems with CZ.

[kt315]

antistatic field protection in any coil, to be its PI or VLF design, does not serve against EMI influence. please read the book INSIDE THE METAL DETECTOR for first.

[Waikiki_Sweep]

antistatic field protection in any coil, to be its PI or VLF design, does not serve against EMI influence. please read the book INSIDE THE METAL DETECTOR for first.

"8" shaped RX coil is best protection from EMI. Any objections?

[Skippy]

If EMI is the problem, I think the less tones you have, the better, or you will just hear what Tom D calls the "HillBilly Jug Band". So, two tones, iron / non-iron will probably sound the most intelligable. Which means machines like the XP GMP / Deus, possibly others that mimic this behaviour, Deeptech Vista? Tom D seemed to say it was a similar machine.
And the obvious answer - fit a smaller coil if you have one.

[Silver Dollar]

I believe when he says this "because in some of my hunting areas the EMI is terrible in discrimination mode"
he means falsing not EMI. If it were EMI it would be just as bad in all metal mode... Thus he should try shielding.

[Qiaozhi]

What I'm looking for is a machine that has tone ID attached to the motion all metal mode. The reason I need this type of machine is because in some of my hunting areas the EMI is terrible in discrimination mode so I switch to the motion all metal mode. No filters.

The term "EMI" stands for Electromagnetic Interference, which is probably the wrong term to use here. I suspect you're really referring to "chatter" caused by lots of ferrous trash in the soil. If you attempt to use all-metal mode with ferrous/non-ferrous tone ID, the sheer number of signals will drive you mad.
As someone else suggested here, the best solution in this instance is to use a smaller coil, preferably a concentric.

[Davor]

Chatters do come from old spark plugs as well, regardless of the shield and a terrain. For that reason a figure 8 coil configuration, or any other humbucker configuration would do good. But ... such configurations have + and - phase responses. Not a problem for PI and not a problem if both Rx and Tx are in figure 8 configuration.

I'm considering a 4 quadrant discrimination scheme where phase vs. counter-phase wouldn't make any difference. The only caveat for a figure 8 in that case is - depth loss.

[Waikiki_Sweep]

Chatters do come from old spark plugs as well, regardless of the shield and a terrain. For that reason a figure 8 coil configuration, or any other humbucker configuration would do good. But ... such configurations have + and - phase responses. Not a problem for PI and not a problem if both Rx and Tx are in figure 8 configuration.

I'm considering a 4 quadrant discrimination scheme where phase vs. counter-phase wouldn't make any difference. The only caveat for a figure 8 in that case is - depth loss.

Inverted phase for "8" coils sure is a problem. I can see a lot of detectorists using that 18 inches "Bigfoot" coils.
I have asked many of them and they are extremely happy with it. It gives huge area coverage, lightweight, great pinpointing and sure NO ANY EMI.
They covering area faster than anyone else and taking all the good stuff from the beach.

Looks like that phase inversion problem they solving by running in "all metal" mode and catching all targets than test them by front half of coil where phase is correct.

At least you can just buy a ready to use coil "Bigfoot" and go detecting.

http://i120.photobucket.com/albums/o...uarterRing.jpg - Photo of "Bigfoot" coil from member CyberSage of forums.whiteselectronics.com

Also I think it is good idea to make a pinpointer with "8" coil because such pinpointer will not have any EMI from working near it metal detector.

[rubydarlene]

Coil still and in the air, terrible chatter, EMI.

[Mark-VA]

That is correct rubydarlene. I might add one thing too, move around and check, I've had some areas that were high in EMI then move 50 yards and nothing. Very puzzling at times.