My Search Programs for Minelab E-Trac & CTX 3030 Metal Detectors

Search Program #1 for Detecting Coins: Level 1 - High Discrimination/Low Noise, page 9

DISCRIMINATION PATTERNS


NOTE: The Smartfind window on the E-Trac Pattern Screen shown below is identical to the Smartfind-2 window on the CTX-3030 Detect Screen in terms of the same FE-CO coordinates system - Minelab's unique 2-Dimensional Scale of Discrimination. The Target Crosshair takes the same spot where it would be on the E-Trac's screen.

The Level-1 Discrimination patterns should be used in conjunction with Level-1 program settings at the metal detecting site of a former settlement or just a single homestead that you visit for the first time and do not know the following:
1) site's "topography" - former locations of main dwellings, stone walls, flower and vegetable gardens, and secondary structures - utility sheds, well(s), pathways, chicken coops, cowshed, pigpens, outhouses, cesspits, etc.;
2) site's status - "virgin" or "searched out";
3) site's current level of junk content - high or low levels of old iron junk and/or modern trash;
4) site's natural level of mineral content (magnetic mineralization) - neutral, low-mineralized or high-mineralized ground, and whether the "sporadic magnetic mineralization" (hearths, pottery, brick, slag, coke, etc.) is interspersed with soil or not.

The following Discrimination patterns are designed for detecting only SHALLOW and UNMASKED coins, jewelry and other non-ferrous "goodies" in the iron-contaminated ground. Even though the Discrimination level is high (all iron is rejected) in these patterns, you may still find deep coins where the iron junk is not too cluttered and the ground is neutral. With these Discrimination patterns, both E-Trac and CTX-3030 respond to deep targets even with low sensitivity settings.

Later on, during your subsequent visits to the site, and after you are done exploring the site and recovering all easy-detectable targets, you should switch to the Level-2 and, subsequently, Level-3 search programs with their Discrimination patterns to get the most out of the site (read more about different search methods and detecting strategies in my article "How To Metal Detect Around Homesteads and Cellar Holes").

Just to remind you that in the E-Trac's Smartfind window, the FE-17 line is a dividing line between the Conductivity and Ferrous zones: on a vertical Ferrous axes, the Fe values from 01 to 17 correspond to non-ferrous targets, and the Fe values from 18 to 35 correspond to iron.

Ferrous and Conductivity Areas in E-Trac's Smartfind Window

The same structural principle is applied to the CTX-3030's Smartfind 2 system of FE-CO coordinates.

To meet the objectives set for the Level-1 search program, I recommend to use this Discrimination pattern for both E-Trac and CTX 3030:

Discrimination Pattern for Level-1 Coin Search Program

Minelab CTX-3030 & E-Trac Discrimination Pattern for Detecting Coins with Least Noise

Entire "ferrous area" (from horizontal FE-18 line to FE-35 inclusively) is blackened, and this is a lot of Discrimination! Coins that are partially masked by nails will not give out any responses because all iron nails are rejected. With Sensitivity set to "Auto", to make your E-Trac's operation quieter, you can increase Discrimination a bit more. However, you should keep in mind that the more Discrimination you use, the less deep targets you hear. With this Discrimination pattern, the E-Trac's responsiveness to deep targets will be below average according to the Minelab standards, but still above the average detecting range of many detectors of other brands.

To eliminate the "wrap around effect" (see description of this effect in my "E-Trac Field-Test Report" page 2), the FE-01 line is also blackened with exception of a gap extending from CO-38 to CO-48 and allowing to detect large silver coins (in the US: Franklin Silver half, Kennedy Silver half, Peace Dollar, Eisenhower Dollar, and Morgan Dollar) and some old European copper coins of large sizes.

The FE-02 line is blackened from CO-01 to CO-31 inclusively to eliminate iron falsing caused by the "wrap around effect" as well ; the rest of the FE-02 line remaining white to accept the large silver coins mentioned above. The CO-50 line is blackened from FE-01 to the FE-07 inclusively to mute possible responses to hot rocks.

To reduce the iron falsing caused by the "wrap around effect" even more, you can also blacken the FE-03 line while keeping the "CO-32 - CO-50" segment white; however, the detector's responsiveness will be also reduced a bit. If you still get some iron falsing caused by the "wrap around effect", blacken the same portions of the FE-04 and FE-05 lines as well. Blackening FE-06 and FE-07 may cause rejection of some thin silver coins (in case they are present in your locality).

Always keep in mind that good targets sometimes, when 1) positioned close to rejected targets, or 2) partially masked by rejected targets, and/or 3) "disguised" by highly mineralized ground, will be identified with FE numbers reaching up to 27 (!) value. Such distorted FE-CO readings of the good targets often fall into certain rejected (blackened) zones, called "Secondary Discrimination Zones" (described on next page), inside the patterns with ample Discrimination.




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