Ground Balance, Sensitivity and TID

[scoopjohnb]

As sensitivity is one of the first things we adjust when switching on the detector,... a few things have had me thinking.

When dropping sensitivity and using ground tracking, automatically the ground rejection will drop as well.
Ok understand that,... less noise means it can use less noise rejection.

However when ground values drop or rise and ground tracking adjusts on the fly,... how does it effect TID?
Can certain targets that just fall below a certain tone break, actually end up in a different tone region??

When searching with a fixed Sens and fixed Ground,... will the actual ground under your coil changing from the fixed setting distort TID??
And how could we quantify the flex in TID if indeed TID was distorted by changing Ground Balance numbers??

 

[rks1040]

I don't have my Deus yet (should be here Friday) But I've been reading a lot,and the way I read the instructions on the V3 version the target ID Norm feature locks the TID into one range for all frequencies, I'm guessing it dose the same for the GB also. It wouldn't be very useful if it allowed changes in the TID,because the GB has changed? Like I said I'm just guessing,I'm sure someone on here has experience with this,and will comment! ID NORM

The Target ID value for a specific target will be consistent across the 4 operating frequencies when the ID Norm option is activated (pg 27).

 

[squirrel1]

Sounds like you are indeed trying for the perfect ID scenario using your detector settings. IMO there are way too many variables associated with how the ground can affect your target response. When in doubt dig it out. I've dug some very good targets using the version 2.0 reading 94-98. Most folks would have walked right by thinking iron all the way. The tone just had just that little too good of a sound to be iron and those digs paid off. I know I've had my deus in manual GB and you can see the ground change by looking at the numbers when sweeping from one small area to another. I usually run mine in tracking and have had good luck. I've not used my 3.0 upgraded deus a whole lot yet. Will try this week to get out with it and see what happens. The deus is a killer machine for me.

 

[scoopjohnb]

I'm indeed trying to get a feel for this Deus thing LOL

Fact is, I've found more small jewelry dirt fishing with the Deus in the short time I've had it.
Then with any of my other units.

Getting it to run as a great coin machine, it needs accurate ID to get a feel for the iffy signals.
When running in GB tracking, the targets tend to sound that little bit more fuzzy.
Running a fixed GB well adjusted to that particular spot, the Deus just comes alive and deep!

Problem with the GB differing from one spot to the next, indeed ID's tend to drop or rise.
Now trying to learn specific target sounds is somewhat difficult if they change the tune on you every few steps,...

Coin machines and steel crown caps, well .... glad they designed Silencer 4,... but it just kills the unit.
It creates a whole mess trying to pinpoint a coin with a crown cap nearby.
The Deus just seems to hang onto that cap.

Anyway,... and here is me thinking out loud again.
I'm going to start over and treat this thing as a jewelry machine, high end TID is messed up anyway.
Back to the drawing board.

Did I mention I've found some nice bling with it,... LOL

Thx for the reply Squirrel

 

[rks1040]

I haven't had my Deus very long,but I found that the TID numbers jumped around a lot! I used NORN ID,and selected YES. This makes the TID read as if it's always at 12 HZ! Now for the other question,do I have to do this for each program,or does it cover all of them on the machine?

 

[Andy Sabisch]

I haven't had my Deus very long,but I found that the TID numbers jumped around a lot! I used NORN ID,and selected YES. This makes the TID read as if it's always at 12 HZ! Now for the other question,do I have to do this for each program,or does it cover all of them on the machine?

The ID NORM function makes all TID values read as if you were running 18 kHz not 12 kHz . . . . . . small point but it makes a difference in terms of what TID values you are looking to see for certain targets.

The ID NORM function is program dependent so you have one program with it on and another with it off

Andy

 

[rks1040]

Why do they use the 18 kHz TID, and not the lower 4-8 kHz TID for NORM ID ? For me (anyway) the 4-8 kHz numbers are spread out better, giving a larger TID reading spread, and separation, between targets. This makes notching out unwanted targets easier!

 

[scoopjohnb]

The 18 kHz capability combined with a very sharp DD coil, makes it have the tendency to high tone any decent conductor.

In Europe the most treassured finds are small celtic gold coins, small middleaged wafer thin silver coins.
Both ID in the foil to pulltab range.

So you want a detector to compound every high conductor in the field, WWI, WWII shrapnel and grenade shards in the high numbers range.
Which leaves you with an expanded low conductor range. Took me a while to figure that one out.

My best result with the Deus has been a castle park hunt for old stuff in between modern trash.
Disc as per standard 12 kHz program, low tone till 35, high tone 35-85, low tone 85-100, audio amp at 0.

Listening for those faint whispers, which dissappear when you turn on the Garett or Minelab pointers.
Not digging a single loud high tone. Often Deus won't even ID the signal, these are the ones I'm after.

This digging has resulted in some 1400-1700 finds in much better shape then those frequently found in the fields which receive too much nitrates.
Killing the coins in the process.

That's my take why they normalised everything at 18 kHz.

 

[Schultzie]

That's my take why they normalised everything at 18 kHz.

I believe you are right... remember, this unit was designed in France, not the USA. They have much different needs there and the unit is built around the 18kHz platform.


Correct me if I am wrong, but doesn't "ground balance" effect how the detector processes the ground mineralization signal by removing it so it is not detected? I do not believe it effects the TID aspect of the display. Therefore the TID's should remain the same... its a matter of, if it is not set properly, the ground mineralization will sound off as a target.

 

[Deusdigger]

Remember if there are any metals close to a good target it will change the TID of that target. I have found it best to rely more on the tones than the TID to choose whether or not to dig.