Most accurate TID

A "more" accurate answer for the question below depends on the following being true.
No trash in the area.
A target (coin) is laying horizontal to the top of the ground.
Let's say at an a depth of 6".

The metal detector you are using has the transmit winding's on the right side and the receiving on the left of the coil.
Now if you approach the coin from a left to right swing of the coil, with the TX side over the coin first will the target ID be more accurate?
Or is there a difference which signal is first?

Whites XLT hands down for pure ID at 6 inches....

Not into windings but especially deep coins go at them from several directions and lets not forget the speed of the swing which all equates to proper ID....

In my area CTX or Etrac

Sovereign hands down...at at depth too. When I was really in tune, I could get a signal and say I bet thats an early wheat, or bet its an indian with a high success rate.Even called a war nickle once before diggin.As for the newer detectors, I find my gb pro to be accurate.

I had a night like that one night using a tesoro vaquero i could call a IH penny or a silver at average depth of about 7"

For the benefit of those who may have misunderstood the original poster's question:
I think he's asking "Will target ID be better if I swing from left-to-right or from right-to-left? That is to say, does it matter whether the TX or the RX coil passes over the target first (assumption being it's a DD coil)
Personally I've seen no difference, it would be easy enough to flip the coil round on most machines (so it's pointing towards you rather than away) in order to try all 4 possibilities. It's tempting to think there could be some difference that a machine might be able to make use of. I'm thinking along the lines of doing an intelligent average of a double-sweep. I suspect there will only be a noticeable difference for iron targets - the 'iron grunt in one direction' and 'high-tone the other direction' effect. It may be useful for combined iron/non-iron targets, like the brass buckle with remains of iron pin attached.



Edited 2 time(s). Last edit at 01/20/2013 07:46PM by Pimento.

sd

Not sure I follow you on the winding's......Are you talking about a DD?

Keith

Pimento Wrote:
-------------------------------------------------------
> For the benefit of those who may have
> misunderstood the original poster's question:
> I think he's asking "Will target ID be better if I
> swing from left-to-right or from right-to-left?
> That is to say, does it matter whether the TX or
> the RX coil passes over the target first
> (assumption being it's a DD coil)
> Personally I've seen no difference, it would be
> easy enough to flip the coil round on most
> machines (so it's pointing towards you rather than
> away) in order to try all 4 possibilities. It's
> tempting to think there could be some difference
> that a machine might be able to make use of. I'm
> thinking along the lines of doing an intelligent
> average of a double-sweep. I suspect there will
> only be a noticeable difference for iron targets -
> the 'iron grunt in one direction' and 'high-tone
> the other direction' effect. It may be useful for
> combined iron/non-iron targets, like the brass
> buckle with remains of iron pin attached.


Thanks Pimento

I will try it the next time I go detecting.

I have never noticed a difference....

I do like elliptical vs Round though.....Less field disruption....Things happen faster..

Keith

*** Now if you approach the coin from a left to right swing of the coil, with the TX side over the coin first will the target ID be more accurate? ***


Don't see how the sweep direction makes any difference. The Rx and Tx coils are inductively balanced. While the Tx coil is the only portion of the DD design that is actively transmitting, it has no means to detect a signal from a target. Likewise, the Rx coil is passive, but has no ability on its own to detect a signal without the Tx coil doing its thing. The two coil assemblies work together - separately they do nothing.

Thus, it is only the decoupling of the Tx and Rx coil when in the presence of a metal (conductive) target or iron (some permeability other than 1) that generates a signal in the Rx coil. That is, some energy from the Tx coil is transferred to the Rx coil.

The target ID has to do with the post-processing of the received signal as compared to the Tx coil signal, which all happens independently of which way the coil is moving. In other words, the direction of swing or side of coil that intersect a target first doesn't matter - it simply will generate a signal and the demodulation of the signal occurs later.

It is true that only one side of the DD coil is actually transmitting (normally the Tx coil is on the side where the cable enters) - but for a voltage to be applied to the Rx coil it has to work as a balanced unit, separately the parts can do nothing to create a signal.