a bunch of 'head scratching' at times.
Ronk, to answer some of all your posts here:
The Teknetics T2 will reject targets okay and give good detection depth with the Disc. setting from '0' up to about '49'. When you adjust to '50' or a bit higher, you will actually get a little increase in Sensitivity, and that = depth (in some conditions).
Now, let's consider detection depth as well as Discrimination and the responses we get, with both Audio Tone (Target) ID and Visual Target ID. There are going to be some variables that are really tough to answer exactly. We'll consider the following: Saturated Audio Vs Modulated Audio circuitry; Ground Mineral influences; Target related considerations and ???.
Saturated Audio Vs Modulated Audio: Some models provide a full audio Saturated response, such as the Teknetics Delta. What does that mean? It means that the circuitry is design such that a certain amount of detection signal is required in order to process the response. If ample signal isn't received for analyzing and processing, it is 'clipped' and you don't hear a thing. Thus, regardless of the target's
processed response depth, you will hear a full-bodied audio sound. If a target lacks sufficient response to process, you won't hear a thing.
With a Modulated audio, which I usually prefer for most detecting, a target's audio response will be fairly strong for maybe the first 3" (depending upon the Sensitivity level used), and then it will start to 'modulate' or trail off as the coil-to-target distance increases. This audio will start to diminish and continue to weaken, even to a whisper, at the farthest coil-to-target distance/depth.
Usually, although not always, a Saturated Audio circuitry will provide a reasonably consistent and proper Tone ID and visual Target ID for all processed signals. Modulated Audio processing is doing just what it does without and without any audio enhancement. This means the deeper-reading targets might have a less than necessary signal to process a 'proper' audio and visual TID response. The result could be a higher or lower than 'proper' reading.
Ground Mineral influences: Manufacturers also have to deal with the ground mineral signal along with a target signal. Ground produces a signal of about 1 Hz to 2 Hz, and there can be various levels of difference in that, too, such as if the ground is loose and porous, moderately packed, or densely packed and on to solid, such as pea gravel. Some might be about neutral some moderately mineralized (referring to iron/ferrous mineralization, and some might be more extreme.
Due to the ground that surrounds a target and the circuitry used for detection, including the search coil size and type, it can be very difficult to process a 'proper' audio or visual TID. Also, I am referring to detecting a target that has been lost and positioned in the ground for a reasonable period of time (over a year) and the ground is all uniform in its consistency.
Once someone digs a hole and places a coin in the hole, it's not going to be 'normal,' either. An exposed hole with a visible coin at the bottom
might not signal at all or it might be weaker than expected, and quite often there is not be a 'proper' Tone ID or visual Target ID. This is partially caused by the disturbance of the ground at that spot and sweeping across the ground the detector has to process the abrupt change in ground signal, and that alone can hamper target detection.
The same is true if the disturbed and loose dirt is put back in the hole on a fresh-buried coin. That's why many people are confused when they try to learn about a detectors detection depth and visual performance potential, but results don't look good. the best 'testing' is by actual, in-the-field hunting for naturally lost targets that are in an undisturbed state.
Target related considerations and ???: This is simply a matter of the target size, shape, position, metal alloy and depth that need to be factored in to get proper visual and audio responses. Also if there is any nearby masking metal. If everything isn't 'perfect' for that detector/coil/ground environment at the time, the visual and audio response might be 'off.'
Through all the years I have been detecting, in a number of different US states and a wide-range of ground mineral environments, I know that sometimes the responses are off a little when I used a Saturated Audio model. I also know that I will get errant Tone ID and Visual Target ID responses when I have used a Modulated Audio model. No, not always, but I do get more targets that will read higher than the target will when out of the ground, or sometimes a lower TID than a 'proper' in-air response would be.
I also know that using a good Modulated Audio model I will find deeper targets, smaller targets, and some 'iffy' targets than I would if using a Saturated Audio model at the same spot and time. I just prefer a good Modulated Audio model, and that includes the Omega ... kind of.
The Omega does have some enhanced signal processing in the d3 and d4 Tone ID options that sort of saturates the audio at least to a certain percentage of its depth, then it modulates more. This is why I mainly like to use the d1 single Tone ID function, to get very good Modulated Audio performance, or the d2 function when I want to hear any typical iron targets.
So, just for the record, I like my Omega with the stock 10" Concentric coil (better discrimination, especially in iron) or the round 5" DD coil, and I have found some deeper coins. Many times the deeper coins, which could be anything from 5" on down deeper, might result in a 'proper' TID, but also could give me an improper higher-or-lower TID response based upon all the variables we have to contend with.
Also, a detector's discrimination circuitry might also need a certain amount of signal to give a proper rejection or visual response. A too-deep target might not be rejected, even if it is below the Disc. set-point. I'm sure Dave J. could give a more 'proper' answer and correct my non technical references. These are just generalities in layman's description.
Monte
at 4-5" deep each. Think Teknetics is on to something here?