One day last October, a friend who collaborates with me and I were en-route from Expo 86 in Vancouver, B.C., to California. By invitation we made a detour to Sweet Home, Oregon, where we spent a wonderful and instructive day visiting the Whites Electronics plant. There was only one restriction: we didnt get within 100 feet of the engineering department Today, this is more than understandable. We undoubtedly would have seen components unlike anything that wed ever seen in a metal detector, parts for the re-cently introduced Whites "Eagle," and the cat would have been Out of the bag.
To some, the Eagle may seem at first glance to be a digital version of the 6000 Di Pro in appearance and performance features. Both have "Autotrac" (an automatic ground balancing system that self-adjusts to changing mineralization), for exam-ple. But a silicone chip, similar to the ones that made personal com-puters possible, permits the Eagle to take up where the 6000 Di Pro (and the Liberty Di) left off. And it does it with no knobs on the control box.
The Eagle is such a departure from any other metal detector that Whites has conducted a series of all-day comprehensive seminars for its dealers and their sales personnel; this allows Whites to unravel the mysteries of the new instrument before they attempt to sell them to customers. I attended the seminar held in Sacramento, Calif., earlier this year as a member of the working press. So, when I received the Eagle that I field-tested, there were no surprises.
The detector was packed in a rugged cardboard container to eliminate any possibility of shipping damage. Assembly was identical to the Whites Pro series detectors and is hardly worth mentioning, other than to note that it was done in a matter of minutes and required no tools. The pole sections slid smooth-ly within each other, and the snap-lock spring tensions were just right.
The Eagle is, at first glance, much like most of the other Whites Pro series detectors: a rectangular blue control box, with a handle, and the pinpointing/returning toggle switch mounted to the meter casing within easy finger reach of the handle. Thats where the resemblances end.
The control box has no knobs.
Since there are therefore no calibrations, the space has been used to show V.D.I. target calibration on one side where the handle extends and start-up instructions on the other side both by means of silkscreen printing. The bottom of the box is used in the same way to show more detailed operating instruc-tions. I found this to be a very handy field reference.
The meter is much more than a meter and unlike anything Ive seen on a metal detector. It consists of a rectangular L.C.D. (Liquid Crystal Display) surrounded on three sides by a cluster of 14 key-pad switches, each clearly marked with its func-tion. The switches replace the usual control box knobs and buttons and then some. The fourth side is a lamp that can be turned on for night operation.
All metallic elements and their alloys have their own signature, due to differences in electrical conduc-tivity. Metal detectors are possible as we know them because they con-duct differently and they allow dis-crimination; factor in mass and you have Probable Target Identification (Probable LD.).
Whites has divided the responses of the most common targets into 95 increments, starting with iron at 00 and working up through the familiar items of junk and U.S. coinage to a silver dollar in the 91-94 range. Virtually all metal detector moving -needle, target identification meters have a numerical scale to help the operator identify frequently encoun-tered targets.
The limitation of the moving-needle meter is space. A scale with 95 readable divisions would mean a meter so big that it simply would be impractical. The Eagles digital L.C.D., however, shows very readable V.D.I. response numbers along with Probable I.D., and the meter takes up so little display space, it simultaneously shows a lot of other information.
Starting up and ground-balancing the Eagle is not very different from other automatic, ground-balancing detectors. The angle of the pole and search coil is adjusted so that when held in the normal search position it is flat on the ground and the toggle trigger switch is in the center position. Pressing ON/OFF briefly brings everything possible onto the screen, as in the accompanying illustration on page 55. This quickly fades, leaving only the outline of a detector its coil in the air; this is the air prompt. With the coil held at waist level, AIR is pressed. The detector will emit either a single beep or a two-tone beep. A two-tone beep means that theres some sort of interference, making it necessary to move to a different location. After moving press AIR again and repeat this procedure until a single beep is heard. At this point, the air prompt will disappear and be replaced by the ground prompt, the outline of a detector with the coil in the search position.
When GND is pressed, the detector will again emit either a single beep or a two-tone beep. The latter means that there is either a target directly under the coil or that there is so little mineralization present that the detectors pre-set ground balancing will be sufficient. If moving to another location and pressing GND again produces a two-tone beep, it probably means there is little mineralization present and the double beep should be ignored.
Next, check the battery voltage. pressing LAMP will bring the actual voltage correct to 1/10th of a volt on the screen as long as the switch is pressed; there is no decimal point. For example, the number 48 would indicate 4.8 volts good working voltage for the rechargeable battery. Fresh alkaline battery packs show about 60 or 6.0 volts. An internal voltage regulator allows either type to be used without changing the detectors performance; if voltage falls too low during operation, LOW BAT will appear on the screen. Pressing LAMP again will turn the lamp off after the battery check has been completed.
When ground balancing is com-plete, the outline of Whites trade-mark will appear at the bottom center of the screen, indicating that the detector is ready to go. Prompts (black bars) next to AUTOTRAC and DISC ON indicate that these functions are on. The "A" next to AUDIO MODE shows that the de-tectors audio will operate a thresh-hold tone. The 3 next to SENS means that sensitivity is at level 3 (1 is minimum; 5 is maximum). Five black bars next to VOL indicate that volume is 5/8 of maximum. This has been accomplished with what Whites designates as Primary controls, those used each time the Eagle is turned on; their switch buttons are labeled in green.
The detector will now operate in a G.E.B./DISC motion mode with Autotrac on, audible threshold search, medium sensitivity and audio volume slightly more than half. The DISC is controlled by a pre-set notch program designed to reject most junk while accepting goodies. I found out in short order that the Eagle rejects most pull tabs while still accepting nickels, solving a common problem with many VLF/ TR detectors, which characteristically wipe Out nickels along with the tabs.
The Secondary controls labeled in yellow are used to make alterations to the Primary control settings, de-pending on conditions and/or per-sonal preference.
Pressing DISC ON Shuts off DISC and the black bar next to this control will disappear from the screen. The Eagle now shifts to a non-motion, ALL METAL mode. Similarly, pressing AUTOTRAC turns off this function, and the black bar next to the control likewise disappears from the screen. You will probably not turn the AUTOTRAC off often. I had great success with the AUTOTRAC on Whites Liberty DI (Lost Treasure, Jan. 87) finding very old coins in an intensely miner-alized area. A friend and I had searched the same area with two more expensive detectors with medio-cre results. And the Eagles AUTO-TRAC is even more sophisticated than the Liberty Dis. If AUTO-TRAC should reach its limit of self-adjustment, the ground prompt that was used for ground balancing will appear on the screen, indicating the need to rebalance. Nonetheless, if you want to shut off AUTOTRAC, you can.
Successively pressing AUDIO MODE will bring up the letters A, B or C next to it on the screen. "A" mode, the initial setting, is thresh-hold hum, motion or non-motion, depending on whether DISC is on or off. "B" mode is silent search until the target has been accepted. "C" mode is audible treshold, but oper-ates in two different ways: When DISC ON is on, it produces a high tone for targets accepted by the discriminate program and a lower one for targets rejected. When DISC ON is off, it produces the lower two for all metals.
SENS controls the Eagles sen-sitivity. Successively pressing it will bring up the number 1 (minimum) through 5 on the screen next to it. It starts out at 3 and each press increases it one increment, until at 5, it reverts to 1 and then works back up. Searching with the most sensitivity local conditions will allow is all-important. A rag-ged or pulsating threshold indicates too much sensitivity and turning it down until it smoothes out is necessary, but sometimes this can be deceptive at least to me. The Eagles SENS is set mainly by sound, but the VDI numbers on the screen are another very useful indicator. If they jump around when a target is encountered, it may well indicate too much sensitivity even if the tone sounds smooth. If its a good target, lowering the sensitivity by one increment will likely stabilize the display.
VOL UP, VOL DOWN controls levels of both threshold and response audio. The lowest level consistent with the operators hear-ing, background noise, etc., is de-sirable. As with all other detectors, the higher the audio level, the shorter the battery life. A bar graph appears on the screen next to these controls. One bar is minimum, eight bars show maximum and the bars begin at five.
Searching, either in GEB/DISC or ALL METALS is done with the trigger-switch toggle at its center position. I found it most effective to search by audio in whatever mode seemed most appropriate; once Id found a target, I consulted the VDI display for identification. The VDI Probable I.D. is calibrated in terms of modern U.S. coins and commonly found junk. A large cent (discon-tinued in 1857) made of copper and slightly larger than a quarter, reg-istered 87 the very top of the quarter range. The Probable Target I.D. also showed a quarter. A Susan B. Anthony dollar, composed of outer layers of copper-nickel bonded to an inner core of pure copper, also was identified as a quarter, for which they are so often mistaken. One thing I always try with any detectors visual target. identification is a sweep across a buried quarter, two inches deeper. Then, I uncover it, put a second quarter in the hole, replace the dirt and make a second sweep. The first sweep always shows a quarter, as it did with the Eagle. The second sweep has always shown a half-dollar, but not with the Eagle. The detector I was using couldnt decide. Operating at a maximum SENS appropriate for the area, the read-out alternated between "quar-ter" and "half," which I think says a lot for its accuracy.
The Eagles Probable I.D. read-out is tied to V.D. I. numbers just as surely as if it were lettered on the face of a moving-needle meter. When I was nugget shooting, hot rocks showed as 00 and were correctly identified as "iron," as were some old bottle caps. Pieces of foil and several pull tabs all registered within VD.I. number ranges assigned to these items by the pre-set DISC program: 01-08 and 28-39, respectively, and were correctly identified. The two nuggets I found each weighed less than half a pennyweight. One registered at V.D.I. 11 and had no Probable I.D., since nothing is related to that number. The other, somewhat larger, had a V.D.I. number of 17 and was identified as a nickel since it fell in that coins 16-27 range.
Pinpointing is accomplished by squeezing and holding the trigger. The detector is then in non-motion, ALL METALS mode and the display shifts to depth reading with depth from 0 to 9 1i2" appearing next to the word deep. A vertical line appears next to the VOL bar chart, which now reads in terms of response volume rather than audio level.
Sweeping the target area with an X patter to locate the center of the coil is suggested. When doing this with a conventional V.D.I. meter instrument, the goal is to have the needle show minimum depth while the audio is at its highest level. The Eagle accomplishes the same thing, but in a much more precise fashion. I found it much easier to "turn" down the numbers on the Deep scale to the smallest number, then move the coil until the VOL bar chart was at its tallest and then move the coil around until both values appear on the screen simultaneously; this method is easier than trying to re-member exactly where the needle was and the audio sound at the magic moment of centering. If desired, keeping the trigger squeezed during pinpointing can be avoided. By pushing the toggle all the way forward, you can lock it into the pinpointing mode.
The blue keypad switches are for Discriminate Control. With these, the pre-set program can be altered to either Accept or Reject as desired.
The letters MEM appear on the screen when the controls are set to alter the DISC program. This means that such changes will be fed into the detectors memory. Shutting the Eagle off reverts the DISC program to the factory original. But, if desired, the new program can be retained by squeezing and releasing the trigger switch immediately after releasing ON,OFF. Your program will stay in the memory indefinitely unless the battery voltage falls below 3.6 (36 on the screen) or if it is necessary to put in a new battery pack to maintain voltage. Its better to periodically check battery voltage than to rely on the LOW BAT indicator. As an added feature, the Eagle will turn itself off if no controls are used for 20 minutes.
This feature lengthens battery life, but it will also wipe out any new DISC program.
The simplest way of reprogram-ming DISC is to teach the Eagle to accept specific targets to pre-set program rejects or vice versa. Both objectives are accomplished in much the same way. To program the Eagle to accept targets, set the controls to search in DISC ON mode. Now, press LRN ACC CLR once; a small prompt next to the switch and MEM should appear on the screen. The, pass samples of the targets to be accepted across the coil, four inches from it four to six times each, or until a good tone is pro-duced. The samples can be either in the air (as in a bench test) or in the ground, but a consistently good tone is necessary. When this step is complete, press LRN ACC CLR again. MEM and the small prompt will disappear and the detector is ready to search. Teaching the Eagle to reject presently accepted targets is done in the same way, except that LRN REJ SET is used.
The factory DISC program may also be altered without passing samples across the loop. Pressing either EDIT Up or EDIT Down brings the V.D.I. numbers onto the screen, one pair at a time. If nothing appears after the number, the DISC is clear to accept it; if the letters SET appear with it, the DISC is set to reject it. Appropriate Probable I.D. names also appear Nickel appears with each number 26 through 27, Pull Tab with 29 through 39, and so forth. MEM is also present all the time. Pressing EDIT Up moves the V.D.I. numbers up; 00 through 95, or anything in-between. EDIT Down moves them down: 95 through 00, or anything in-between. Any number which is set to reject can be cleared to accept by pressing LRN ACC CLR. Conversely, any number cleared to accept can be set to reject by pressing LRN REJ SET. Squeezing the trigger switch returns the Eagle to the search mode.
During one coin shoot in DISC. I got into a nest of bottle caps that showed up at the bottom of the 1 10~ range (V.D.I. 60-82), all at about the same depth as the coins Id been finding. They were eliminated by setting the lowest numbers in that range (60-64) to Reject. I still kept finding pennies and dimes and the bottle caps still kept showing up on the Probable I.D., but they didnt come through on the audio.
Another option permits the rapid editing of large blocks of V.I.D. numbers. Using a four-inch coil, rather than the standard eight-inch requires lowering them. To block edit, press either EDIT control to bring the V.D.I. numbers and MEM on the screen. Then scroll (run the numbers) up or down to the first number of the block to be changed. Holding down either EDIT will parade the V.D.I. numbers across the screen in rapid succession. It doesnt take long to control stopping at the desired number and, since nothing happens until another control is pressed, the operator can experiment indefinitely. When the desired number is showing, the block can be changed from accept to reject or vice versa by pressing twice either LRN REJ SET or LRN ACC CLR. Then scroll until the last number to be changed appears by pressing EDIT in the desired direction. The first few times I did it, I overshot, but easily corrected this reversing my overshoot one number at a time.
One of the features that I like the best is Whites Two quadrant V.D.I. ideally suited to artifact hunting. One of the problems of all metal detectors, the Eagle included, with Probable I.D. is that all ferrous metal targets are identified as Iron. Two such widely diverse items as my black iron gas pipe buried 18 inches in earth below two-inch-thick common bricks, and a 19th century four-inch-long square building nail buried three inches down in my test bed, showed the same thing: 00 Iron. However, in Two Quadrant V.D.I., which is a 95 increment minus scale starting at 00 and devoted entirely to ferrous o metals, the gas pipe showed -89 Iron and the building nail - 09 Iron.
You get into this scale by pressing and holding LAMP and then pressing and releasing GND. The screen clears, showing only the battery voltage and a prompt with the next to highest bar of the volume bar graph. When LAMP is released, the screen returns to its searching configuration; if the lamps stays on, it can be shut off by pressing LAMP again. Any resulting minus readings are identified as such by the word LOW, borrowed for the occasion from the LOW BAT indicator.
The Quadrant might eliminate the building nail, which is to artifact hunting what the pulltab is to coin shooting. My initial sweeps in All METALS during the artifact hunt with some friends produced a series of 00 Iron readings, all of which turned out to be building nails. The site seemed to be slowly filling with earth through wind action and some were at the limit of the Eagles read-out (9 1/2") or beyond, eliminating the possibility of guessing a targets identity by its depth. In Two Quadrant, other nails read between 2 LOW and 10 LOW, we just didnt dig anything that read 10 LOW or less. We unearthed some rather nondescript, ferrous-metal household items in the 15 LOW to 25 LOW range and some non-ferrous items that read on the plus (normal) side.
Finally, a friend who was searching with the Eagle, hollered. "Hey! Ive got something that says 90 LOW!" He dug it out and came up with a fine 7 1/2" diameter, old -fashioned cooking pot with a conical cover and a 2" vent at the center well over a foot down. Its predominantly ferrous, but the lack of rust and corrosion indicates some sort of alloy. Since this was a field test, before he dug it, I returned the Eagle to its normal ALL METALS search mode and all the metal indicated as 00 Iron and a 9 1f2" o depth no different from some of the building nails Id dug that day. Like all other Whites top-of-the-line detectors, the Eagle is designed as a general purpose instrument. It fulfills this requirement admirably and has important features not found on any other detector to my know-ledge. I think of it as evolutionary rather than revolu-tionary Sometime, certainly, metal detectors and compu-ter technology just had to get together as in the Eagle.
At a price of $769.95, the Eagle may not be for the hobbyist with just a passing interest in metal detecting, but the possibilities offered by the Eagle may just be enough to convert a passing interest into an avid enthusi-asm.