Detector Test Report

Detector Test Report
November 2004

The annual hunt of the Warrior Basin Treasure Hunters Association of Alabama offered a superb opportunity to compare depth performance for a wide variety of new and old metal detectors. Efforts were made to keep conditions as uniform as possible. Buried copper pennies attached to the ends of wooden dowels cut to exact lengths were used as targets. All detectors were set to discriminate the same square pull tab with sensitivity set just high enough to avoid excessive chatter. Dependable results were obtained for fifteen current and seven discontinued machines.

Limitations of this study must be noted. Tests were made in average soil mineralization conditions (an MXT gave a reading of 62). This was favorable to detectors with preset ground balance since they usually can handle these soil conditions much better than in high mineralization. Tougher conditions need adjustable ground balance to get optimum performance. Other factors besides depth important in detector evaluation include trash penetration, accurate metering, trash separation, pinpointing, electrical interference, quiet operation, false signals and "human engineering." People's idea of proper sensitivity settings can vary. The depth capabilities of White's XLT, for example, were reevaluated upward when it was found that several users had the gain set far too low. Finally, search coil sizes varied and it is important to consider this when comparing detectors.

Some additional information to consider is available in the remarks section of the following tables. Comments on several detectors are found in the conclusion. Air tests in all metal on a 1/10 ounce gold coin are included in the tables solely as a measure of gold sensitivity.

Adjust GB, Meter & tone ID, Freq. shifter, tested in preset mode

Preset GB

Conclusions

The two best performing detectors were White's MXT at 10" and Fisher's CZ-70 at 9" (both signals were weak). However, the Fisher used a smaller search coil -8" vs. 9.5" for the White's.

This writer owns an MXT and finds it to have many virtues but one great fault. It has very poor trash penetration. The 9.5" standard coil is useless in trash. It is best used on old sites with little aluminum junk where it's very real depth capabilities shine. In other areas such as nugget shooting, relics, and beachcombing, it may be among the very best machines available.

The Fisher CZ-70 has a crude metering system which the user informed me requires accurate ground balancing to work right. When this is done it performs well. It gave an accurate "coin" reading down to 8.5" of it's 9" depth. Fishers are sometimes thought to be a bit iron sensitive; the CZ-70 user said his "likes nails at nine inches." Several Jackson, Mississippi Fisher users said their machines ground balanced okay in the tough soils of their area. Unfortunately, the new Coinstrike was not available to test but a Fisher tech informed me that its depth is the same as the CZ-70.

Among older machines the real surprise was the 20 year old Fisher 1265X. Depth wise it is just as good, in my opinion, as any preset ground balance detector today. Its trash penetration is good, too.

When allowances are made for different coil sizes, the other high end detectors can be expected to all have similar depth performances without some of the quirks of the two top machines. It would be advisable to avoid detectors with ground balances preset in discriminate mode in any region with highly mineralized ground.