Fisher Research Cz-7a Metal Detector
By Jay Pastor
From Page 40
July, 1998 issue of Lost Treasure
Taking the new Fisher m-scope CZ-7a out for a test drive made me feel like a kid again. It brought back the era when all you had to do, while shopping for a worthwhile piece of equipment, was to look for a familiar trademark and the stamp Made in U.S.A. You had the confidence that whatever you wound up with a can opener, a lamp, or a locomotive would do that job right.
Fisher Corporation was in business even back then. It started out in the early 1930's, when there were zeppelins in the air, radio aerials on the roofs, and trolleys sparking along the streets. During the past 67 years, it has maintained its leadership with continually evolving, intelligently designed detectors that often push the state of the art.
For the CZ-7a, Fisher wanted to deliver a top of the line instrument sort of a dream detector that surpassed even its popular CZ-7 QuickSilver. But how do you improve a machine that already offers the following powerful capabilities?
In the CZ-7, operation is automatically controlled by a microprocessor that allows programmable seven notch accept/reject discrimination. Dual-frequency operation, coupled with Fourier (pronounced the French way: Four-ee-yay) signal analysis a complex mathematical filtering technique (also employed in sophisticated radar and audio equipment) evaluates responses from buried targets, providing crisp discrimination and greatly increased detection depth. A simplified, manually-operated control allows subtle ground-balance adjustments. Operating modes are selected by touchpads that almost anyone can manipulate easily (pads are raised and can be felt even through light gloves). You can backlight the liquid-crystal mode selection and bar-graph visual target readout display by pressing a switch; theres an accompanying, three-tone audio target identification signal as well as the visual display. Operation is silent until a target is detected; whereupon a clear-cut signal (something like the plunk of a guitar string) lets you know that theres something underground.
A telephone bell (the soft ring of an electronic phone) sounds when the detector encounters large targets, thereby helping you avoid incorrect readings. Tuning in All-Metal mode is automatic. Pinpointing and depth analysis (an all-metal operation) is non-motion and initiated by the touch of a button. A VCO (voltage-controlled oscillator) raises the amplitude and the frequency of the tone indication as you approach the target. (This sound, however, can be quite shrill if the volume isnt adjusted properly.) The light-weight, open, spider search coil is fully encapsulated and immersible. A firm S-frame shaft, that feels as secure as a solid bar, permits three-part disassembly, making it easy to pack for a trip. Miserly-efficient circuitry minimizes battery drain you get 90 hours on a set of alkaline AAs. The detector is also smart-looking and easy to maneuver.
To demand improvement in a machine of this caliber is something like asking Rolls Royce to come up with a smoother-handling limousine. Right now, Im looking at the first production model of the CZ-7a and have just finished putting it through its paces. Heres what Ive discovered:
Besides offering all the capabilities of the CZ-7, the CZ-7a has the following new features: A unique, waterproof, internal speaker makes headphone use optional and completely does away with the need for an accessory rain cover. Inserting a captive rubber plug into the headphone-jack makes the control housing completely weatherproof impervious to rain, splashes, and dust.
The three-quarter round lower stem has been replaced with Fishers original round, nylon-reinforced fiberglass double-locking stem.
New electrical features include faster response when Pinpoint mode is selected and storage, without battery drain, of last settings in use just before the detector was turned off (settings are held in memory, even if batteries are later removed).
Although the sun shone brightly during an exceptionally warm February week, a few cumulus clouds wouldnt have been a threat, because both control housing and battery case are sealed.
It took me less than a minute to put the detector together. The isolator stem slides in easily and locks in place neatly and solidly. The replaceable search coil (already assembled) is adjusted with a single nylon wing-nut that keeps the coil set at the attitude you select. (The coil doesnt slowly slouch downward during use.) Dress the coil cable neatly, about half a dozen loops, around the shaft; insert the connector into its keyed mate on the control housing and screw the connector collar finger-tight. Thats it.
This is a very powerful detector. At first, I thoughtlessly tried to operate it with factory (Preset) settings in the house and received mostly bell-tone responses. Sobered by the instruments sensitivity, I took the CZ-7a outside to a well-hunted field that had previously produced Colonial coins. Many have told me its hunted out; Ive had no luck there myself lately. But, within the first few minutes I got several hits. Over half of them were deep (one read 10-inches), but the ground was too frozen to dig.
I pressed the Pinpoint touchpad and immediately began to count. Pinpoint was initialized before I got to three - nothing to complain about there. The VCO works well, but, unfortunately, I couldnt dig anything up to determine how close I had come. I placed a few coins on the surface of the ground; the pinpointing that way was about as accurate as you can get.
I have no doubts whatsoever that when I return in the spring there will be several good finds awaiting me. (For summer THing with the CZ-7 model, refer to the Field Test by Joe Patrick that appeared in our December 1997 issue.)
For additional confirmation, I checked two other areas and in one was able to pry a few modern coins out of the stubborn soil. But I think the good items will start appearing in May; Im looking forward to it.
Afterward, I set the machine for an odd group of operating conditions, rotated the Power control to OFF, and removed the battery holders (theyre drop-in and self-connecting/disconnecting). After an hour, I reinstalled the batteries and energized the machine to verify that the last operating selections were still in effect. They were.
Im very much at home with this new detector. Although I respect its power, I tend to relate to it like an old friend someone Ive known for years and feel comfortable with. Dealers tell me they dont get Fisher detectors on trade-ins, even from someone who buys a new Fisher machine. He still keeps the old one.
From everything Ive seen so far, the CZ-7a is a class act, well worth considering for all kinds of land-based treasure hunting simple enough for a novice, and powerful enough for a pro. Its a very fine machine.
Summary of CZ-7A Leading Particulars:
General Appearance: Smart, yet subdued. Weight: Four pounds (very nicely balanced). Operating Frequency: Dual (5 and 15 KHz). Microprocessor Frequency: 1 MHz (for rapid response). User Controls: Tactile feedback touchpad mode select. Power/Manual Ground Balance rotary control. Sensitivity and Volume touchpad adjustment. Modes of Operation and Options: Motion discriminate. Motion All-Metal (auto-tune, widescan). Faint-target audio boost. Non-motion Pinpoint (VCO)/Target Depth. Wet sand compensation select. Display: LCD with Bar-chart. Displays modes, discrimination notches, target ID cursor, target depth, battery condition. Backlight selection. Sophistication: Microprocessor control. Dual operating frequencies with Fourier domain signal analysis. Ease of Handling: Turn-on and go operation. (Additional adjustments convenient for the experienced user). Very comfortable to use. Ease of Mode Selection and Operation: Learnable first time operated. Ease of Assembly: Fast and Simple. Frame Style: S-frame with removable handle and isolator stem. Battery housing below arm rest. Search Coil Style: Submersible 8-inch Spider potted in lightweight glass-bead epoxy, in an injection-molded ABS housing impregnated with carbon fibers (10-1/2 inch and 5-inch diameter coils are available). Control Housing: Injection-molded, high-impact ABS. Sealed against splashes, rain, and dust. Power Requirements: 12 AA alkaline cells provide up to 90 hours of operation (carbon cells supplied). Connectors: Stereo phone jack (1/4-inch). Five pin female connector for search coil cable. Special Features: Seven-notch accept/reject selection with target icons. Automatic, wide scan, all-metal-mode tuning. Touchpad springs back when pressed and released. Three tone target-identification signal. Instructional Material: Illustrated operating handbook. Target retrieval-technique brochure. Technical Backup: Call the numbers listed below, M-F, 8 a.m. through 5 p.m. (Pacific time), for technical assistance. Warranties: Liberal. Five year (first year: parts and labor; next four years: parts only).
For more information, write to Fisher Research Laboratory, Dept. LT, 200 W. Willmott Rd., Los Banos, CA 93635, or call 209/826-3292. (To send a FAX, use 209/826-0416; for e-mail, use firstname.lastname@example.org). To get the name, address, and phone number of your nearest Fisher m-scope dealer, call 1-800-MSCOPE-1 (i.e., 1-800-672-6731). You might also enjoy visiting Fishers Internet website at: hhtp://www.fisher lab.com