Test garden depth????

[Herb Jones]

I dug a test garden. Planted some
Coins at 2" increments... I can only get my vaquero to hit a quarter
Down to 8" sporadically. I am maxed out on threshold
Dialed just back from maxed on sensitivity ( until it just stops chattering), and am
Running just a touch 1/8-1/4 turn negative on my ground balance ( which I have dialed
Up and down With little to no effect on depth
And my soil if clean moist and doesn't seem to have heavy mineral problems and I am
Running both the stock 9x8 concentric Coil, and also the 10x12 wide scan
Without too much luck at gaining greater depths... anything seem wrong with the set up?
What depth are you all getting?

 

[pinenut]

..try backing threshold to a low hum, turn sensitivity high but still stable, then do a "power balance" in discrimination mode. Once power balanced in disc, then try getting the sensitivity up as high as you can without becoming unstable. An occasional chirp is OK, constant chattering is too much. That should give you best depth and best response on a quarter. For some reason, being a little too positive will give a weak response on quarters. I wouldn't bother with "supertuning" as you lose info on target depth with threshold cranked up.

 

[Herb Jones]

Thank
You for the tip
Much appreciated

 

[slingshot]

Also, depth will be less if the test garden is relatively new.

 

[Herb Jones]

I made a plug cutter.
1.5" pipe driven into the ground at the required depth.(I markers the outside
Of the pipe In inches. I just give it a twist and
The plug is removed all The way to the Bottom.
Drop in a Coin and then reinsert the pipe
Into the hole and use
A plunger/stick to keep the core
Sample in place while you remove the pipe.
So I didn't really
Dig, and the soil above the target is minimally
Disturbed since the core sample
Plug is Intact.... you can not even tell the ground is
Disturbed

 

[pinenut]

What is commonly called the "halo effect" takes a bit of time to happen. It comes from the metal being partially oxidized into the surrounding soil, and it will help to increase your detector depth. It's pretty obvious for example, when you set your detector to just reject a new bottlecap, but the rusty ones sound worth digging...until you dig 'em out and then they're properly rejected. The surrounding "halo" of rust in the soil is making the bottlecap seem like a bigger target. Over time, most coins give a similar effect, but to a lesser extent than iron.

 

[2 Much Trash]

It could be that when you dropped the quarter in the hole it landed vertical instead of horizontal. If that's the case it would be tough to get a good signal

 

[Herb Jones]

All
Are
Lying flat
On the bottom

 

[Herb Jones]

I feel confident the coins are
Oriented Properly (flat) but I hadn't consider d halo
Effect. I will tak some
Notes of readings over time
And see if they change

 

[slingshot]

I feel confident the coins are
Oriented Properly (flat) but I hadn't consider d halo
Effect. I will tak some
Notes of readings over time
And see if they change

As the interrupted soil and target lay, over time they will leach into each other and the response should improve. You essentially broke an electrical circuit.

 

[Stoof-tabsallday]

Older the garden, the more settled the ground is.
Penetrates deeper.
Just like moist ground seems to reach deeper than dry ground.
Less air pockets for the signal to have to go through.

Not sure if it's science, just what I've noticed and how I explain it to myself

 

[jld66]

Fisher Labs on their info site wrote a good piece about the halo effect. It has more to do with metals that rust or corrode and leach that into the surrounding soil. Coins do not rust and corrode very little. So the halo effect is not a big factor with them as say iron, zinc, etc. Time in the ground does have some effect with coins. But, as far as the halo effect with coins, silver, solid copper or brass, and such metals is minimal at best. I'd say in about 5 or so years, you will get better a hit on them though.