Fisher Gold Bug Metal Detector with 5" DD Search Coil

A general-purpose coin VLF running 7–13 kHz misses small, low-conductivity gold that registers as noise at standard coin frequencies. The Fisher Gold Bug metal detector runs at 19 kHz, tuned for gold nuggets, flakes, and low-conductivity relics that signal too faintly on lower-frequency machines. Ground Grab® computerized ground cancellation keeps the threshold stable in the iron-rich, highly mineralized soils where placer gold concentrates, without the false signals that force you to back off gain and lose depth. Fisher has built detectors in El Paso, Texas since 1931, and the Gold Bug is the brand's dedicated 19 kHz gold prospecting and relic machine.

What You Gain Coming from a General-Purpose Detector

• Frequency matched to gold: Standard coin machines run 7–13 kHz and assign rising target IDs to silver, copper, and iron. Gold nuggets and fine flakes register unreliably at those frequencies. At 19 kHz, the Gold Bug's transmitted field interacts far more strongly with small, low-conductivity targets, which translates directly to detectable signals on the gold you are actually hunting.
• Stable threshold in mineralized ground: Ground Grab® sets automatic computerized ground balance in under two seconds. On a machine with fixed or no ground balance, mineralized soil generates constant false signals that force lower gain and reduced depth. Ground Grab neutralizes that noise so you can run the gain where shallow sub-gram targets are still detectable.
• Proportional VCO audio: The Voltage Controlled Oscillator responds proportionally to signal strength, so pitch and speed tell you something about target depth and size before you dig. A two-tone coin machine gives you on or off; the Gold Bug gives you gradations.
• 1–99 numeric target ID on a large LCD: Visual confirmation alongside the audio. In Discrimination mode, notch rejection lets you focus on the conductor range where small gold and non-ferrous relics live while filtering iron and foil.
• Day-long ergonomics: At 2 lbs 8 oz with a padded armrest, the Gold Bug handles full days across dry washes and creek banks without the arm fatigue that comes from 3–4 lb coin machines.

The Fisher Gold Bug Pro is the step up: it adds a Ground Phase readout showing the actual soil mineralization number on the LCD, giving manual balance more precision on hot or variable ground.

What's in the Box

• Fisher Gold Bug Metal Detector
• 5" DD Waterproof Search Coil
• 2-Year Fisher Manufacturer Warranty

One 9V alkaline battery is required and is not included. We recommend a quality alkaline for the full 15–20 hour runtime.

Gold Prospecting and Relic Hunting with the Gold Bug

Gold Nugget Prospecting in Mineralized Ground

Iron-saturated soils across Nevada, Arizona, and California's Mother Lode country produce the continuous ground signal that makes most coin machines unusable without severe gain reduction. Ground Grab® sets a cancellation offset that smooths the threshold and lets you run the Gain dial high enough to stay sensitive to shallow sub-gram targets. In All Metal mode with a balanced threshold, any deviation from smooth, including the faint rise of a small gold flake, cuts through. The 5" DD coil's narrow detection field averages a smaller ground footprint than a large concentric, further reducing mineralization noise on hot soils.

• Mode: All Metal
• Gain: 5–6 in severe mineralization; raise slowly until threshold smooths
• Ground Balance: Ground Grab auto, then fine-tune with +/- buttons for positive or negative offset
• Discrimination: Off (All Metal mode)

Relic Hunting on Iron-Heavy Sites

Old homestead foundations, abandoned mining camps, and Civil War-era farm fields combine dense iron trash with occasional non-ferrous targets. Discrimination mode lets you adjust notch rejection to knock out iron and foil while keeping the coil sensitive to the conductor range for small copper, lead, and brass relics. The Fe readout adds a second data point: a repeating mid-conductor signal with a clean Fe reading on a productive site is worth a dig.

• Mode: Discrimination
• Gain: 7–8
• Ground Balance: Ground Grab auto
• Discrimination: Iron rejection set to filter low-conductor trash; adjust based on site density

Creek Bank and Dry Wash Hunting

Creek beds and dry wash channels concentrate placer gold in bedrock cracks and gravel benches. The 5" DD coil fits into tight bedrock crevices where a 10" coil passes over the top. Rebalance Ground Grab any time you move from dry to wet material. The searchcoil is waterproof for work at the water's edge and across shallow riffles; keep the control housing above the waterline.

• Mode: All Metal
• Gain: 5–7 depending on black sand content
• Ground Balance: Ground Grab, rebalance at each soil transition
• Discrimination: Off

19 kHz VLF Technology and Ground Grab® Explained

VLF detectors transmit a continuous sine wave into the ground and read the phase shift returned by metal targets. Standard coin detectors run 6–13 kHz, optimized for high-conductivity coins and large jewelry. At those frequencies, a 0.2-gram gold nugget barely moves the phase response. At 19 kHz, the Gold Bug's transmitted field interacts far more strongly with small, low-conductivity targets, including gold, producing signals detectable enough to act on rather than dismiss as noise.

Ground Grab® is Fisher's computerized automatic ground balance system. Pump the coil over the ground while holding the button, and the machine samples the soil and sets a cancellation offset that suppresses mineralization. Once balanced, the +/- buttons fine-tune manually for positive or negative ground response, useful in variable terrain where soil transitions from dry powder to wet clay within a short distance. VCO audio then translates signal strength into pitch and speed: a faint target produces a short, slow rise; a strong shallow target produces a full, fast response. Listening for repeatable, consistent VCO response across multiple swing angles is the most reliable indicator of a real target versus noise.

Build, Display, and Audio

The Gold Bug weighs 2 lbs 8 oz (1.13 kg). The control box mounts at the rear of the arm closer to the elbow, keeping the front end light over long swings. Separate Gain and Discrimination dials, the Ground Grab button, mode selector, and +/- trim buttons are all accessible with a gloved hand. The large LCD displays the 1–99 numeric target ID, depth indicator, Fe readout, and signal strength bar simultaneously. No backlight; it reads well in daylight and open-shade conditions.

Audio runs through the 1/4" headphone jack; standard full-size headphone plugs fit with no adapter. Runtime is 15–20 hours on a single 9V alkaline. A pinpointer speeds recovery considerably in bedrock cracks and deep gravel; we stock the Garrett Pro-Pointer AT alongside the Gold Bug as a complete prospecting pairing.

The 5-Inch DD Search Coil

The included coil is a 5" DD (double-D) configuration. The DD design sends a narrow blade-shaped detection field below the coil face rather than the broad cone of a concentric coil. For gold prospecting, the narrower field averages a smaller footprint of ground per sweep, which reduces the mineralization signal that generates false responses on hot ground. The tight footprint also fits into bedrock crevices and narrow wash cuts where gold concentrates in placer deposits. The coil is waterproof for creek edge and shallow riffle work; the control housing is not rated for submersion.

Specifications

• Frequency: 19 kHz
• Technology: VLF (single frequency)
• Search Modes: 2 (All Metal, Discrimination)
• Target ID: Numeric 1–99
• Fe Readout: Yes
• Ground Balance: Ground Grab® Automatic + Manual Fine-Tune (+/-)
• Discrimination: Adjustable Notch
• Audio: VCO (Voltage Controlled Oscillator) + 2-Tone (Low and High)
• Display: Digital LCD (no backlight)
• Pinpoint: No-Motion
• Memory: Yes (saves custom mode settings)
• Search Coil: 5" DD (waterproof)
• Headphone Jack: 1/4"
• Weight: 2 lbs 8 oz (1.13 kg)
• Battery: 1 x 9V alkaline (not included; alkaline recommended)
• Battery Life: 15–20 hours
• Weatherproof: No (searchcoil waterproof; control housing not rated)
• Country of Origin: USA
• Warranty: 2 Years (Fisher manufacturer warranty)

Why Buy from Serious Detecting

We are an authorized Fisher Research Labs dealer, which means every Gold Bug ships with the complete factory package and registers for the full 2-year Fisher manufacturer warranty. Our team runs the Gold Bug and Gold Bug Pro in the field, so when you call with a ground balance question on your first prospecting trip, you reach someone who has used the machine in the terrain you are hunting. Free shipping, a 30-day return window, and a price-match guarantee against any authorized US dealer. For prospectors comparing the full range of gold-capable machines from dedicated VLFs to pulse induction, our best gold metal detectors guide covers the full spectrum with ground-type recommendations and side-by-side comparisons.