we each need to figure out what is best for us and the types of sites we hunt, what we are after, and the level of trash we plan to deal with.
From the Racer Owner's Manual we can refer to the following, and I made some key points bold and colored:
Gain in Discrimination Modes
Page 16 Gain and Threshold
Since the threshold setting is not available in the discrimination modes, you can increase the
depth of the device or ensure noise-free operation on different grounds only by using the Gain
setting.
In order to adjust the Gain in the discrimination modes, first ground balance while the Gain is at
its default setting. After ground balance is completed, hold the search coil still or swing over the
ground at search height. Reduce the Gain if device receives noise. If not (ensure that the ID
FILTER is also at its default settings when checking this), increase the Gain gradually until there is
no popping sound. If the device starts to receive noise during searching, reduce the Gain
gradually.
NOTE: The electronic Gain of the RACER consists of 3 levels to eliminate the internal
electromagnetic noise and to adjust the saturation level. The electronic Gain change points
correspond to levels 39 and 74 on the Gain setting. In case of saturation, you may raise your
search coil a bit or adjust the Gain to the lower electronic Gain level. For example, in the All Metal
and Two Tone modes, if the Gain is set to 75 or above and if saturation occurs, adjusting the Gain
to 74 or 39 will minimize or eliminate the saturation. Similarly, if you experience saturation in the
Three Tone mode, adjusting the Gain to 39 will be sufficient. Reducing the Gain will not cause a
dramatic decrease in depth.
Also, each of us might have some different thoughts on just what a "trashy site" is, and that makes quite a difference in settings we each use. In addition, the settings used are only a part of how successful we might be, and other factors come into play such as:
• Search coil used.
• Search coil sweep speed.
• Search coil presentation, to include coil height and being overlapped sufficiently.
• Operator's level of patience and commitment to recover what they perceive to be a 'questionable' or 'iffy' target signal.
Since may of '69, the bulk of my hunting has been at older, out-of-use sites that abound in various levels of iron debris. Nails, rusty tin and other ferrous junk. And when I say they abound it in, I mean you're not likely to find any other type of site as challenging as these places. Due to the nature of the locations I hunt, I almost NEVER use more Discrimination than just enough to barely reject iron nails.
With some makes and models that feature Tone ID to help classify ferrous and non-ferrous targets, I will often search with a lower Discriminate setting and rely on the coil used, the performance provided, the settings that work, and operator skills and search techniques to achieve success. This is especially the case with models I use from both Makro and Nokta.
With the Makro Racer, it uses the small 'OOR' coil the vast majority of the time due to the brush, building rubble and dense trash I deal with. My primary settings are:
Gain: '85' when I start working any location. After GB is achieved, I search the site and adjust the Gain as desired based upon EMI, density of targets, etc.
ID Filter: I use the default start-up of '10' and usually leave it there, but might adjust it to no more than '24' if iron nails start to annoy me, or I might reduce it if that would be in my favor.
I never speed through a site. Instead, I work the search coil is a slow and methodical manner with straight side-to-side sweeps, then I 'scribble' the coil when in amongst dense brush and rubble to make sure all spots as possible get searched. Quite often I visually grid sections of the areas I want to hunt to be more thorough.
I have friends who use their Racer at only the default settings, some who increase the Gain almost always, and some who tend to reduce it to the '35' to' 55' range based upon what they have been comfortable with. Just work with your Racer to figure out the best settings of each adjustment function that seem to fit your hunting needs.
Monte
