F75 LTD Sensitivity, Tone ID and Depth

Mark......you are so close to margin!.....yet, I would choose Sens 45 and Disc '1'. Especially in bad dirt. And this is to imply how much performance loss there is...... by virtue of going from Disc '4'.....to Disc '5'.

Steve.......if I understand your question correctly: Even though the audio tone....and the VDI are divorced/independent.......a low tone iron signal .... will most always ID in the iron VDI range also. ... Problem is..... if mineralization is fairly bad........say.....a 8" deep dime 'just' starts to read/ID as 'iron' at 8" and deeper...............................there is extreme difficulty determining deep coins from TONS of actual iron nails. You may 'test' your dirt.......by burying a dime at increasing depths.....until you find where it starts to ID as iron. You may also learn that the dime can be detected all the way to depths of 12"..........BUT........anything beyond 8"...and it ID's as iron. Bad soil really hurts!

Mr. D. --

Yep, you answered it -- saying that bad soil will hurt deep TID/VDI.

Test garden is being planned, but before finalizing, I need to buy your DVD. I think this will be a real education (both your DVD, and getting a test garden "planted")!

Steve

When hitting a suspected fringe target in heavily mineralized soil......would dropping from let's say.......4 tone........to 2+ tone....improve the audio & TDI reporting. And would depth increase? And by how much? Mind you, the questions pertain to highly mineralized soil. (As questions relate to my T2 unit)

The reason I ask is because leaving the unit in the Tone's setting when hunting, would seem to be the fastest & easiest adjustment to make for verification, if answers to above questions are 'yes'.



Edited 3 time(s). Last edit at 02/17/2011 07:15AM by TerraDigger.

Terra, that's a great question. I hunt in 4-tone, mostly. I can't IMAGINE that changing tones would improve TID; I could see where it may "improve" audio, but I could also see where more junk would sound "good" too. I am likely wrong about all this, though, and am interested to see what others say about this.

Steve

I have found no change to TID, audio quality or depth by changing tone. But there are unmasking qualities resultant from different tones. Tom describes this in his early articles on the LTD.

"Mark......you are so close to margin!.....yet, I would choose Sens 45 and Disc '1'. Especially in bad dirt. And this is to imply how much performance loss there is...... by virtue of going from Disc '4'.....to Disc '5'. "


Thanks Tom, this was the answer I was looking for. My test were showing the sens 45 and disc 1 being my best choice for the locations I've been hunting. At times I can run the sensitivity higher.

Thanks

I kinda figured you would do better at lower sensitivity.

NASA-Tom Wrote:
-------------------------------------------------------
BUT..................if
> you ever test a Type-1 U.S. $1 gold coin (1849 -
> 1854) in the 'cl' mode,,,,,,,you will instantly
> have extreme appreciation/amazement for this
> technological advancement that is incorporated
> into this detector. The Type-1 one-dollar coin is
> the smallest Federal Issue coin from the United
> States mint. It'll slightly overlap the head of a
> pencil eraser......when rested on top. In areas of
> minimum EMI.......and with the F75 in 'cl'
> mode.......it'll air-test detect this tiny gold
> coin to 17". There's plenty of detectors on the
> market that cannot detect a silver dollar to 17".
> I consider this Type-1 $1 gold coin to be a
> mandatory standardized calibration/validation
> target for the LTD's and SE's.

17"... wow!

I don't have a $1 gold piece but there is a coin show coming to town in one week. I will purchase one and bury it for testing.

My test bed is ~7 years old but 'acts' identical as it did after one month. Earlier on this forum I described how I initially prepared this bed in my red clay soil.

Different tone options does not increase depth nor enhance ID resolution.

The 17" on the Type 1 U.S. $1 gold coin.......is "air-test" results.......with minimal EMI. It's an eye-opener.

Tom, how deep do you estimate the LTD running in CL mode can see the $1 gold in medium soil?

It will be quite an 'eye opener' should it disappear!

Understanding that 'medium' is a vague term; yet, I would suspect approx 8" depth.