✅ MADE IN THE USA

✅ 2-YEAR WARRANTY 

✅ FREE U.S. SHIPPING ON ORDERS OVER $50 

✅ SINCE 1931 – THE PIONEER IN METAL DETECTING

Impulse AQ Limited
Impulse AQ Limited
Fisher Impulse AQ Pulse Induction Metal Detector Infographic Highlighting Key Features and Specifications
Impulse AQ Limited
Impulse AQ Limited
Impulse AQ Limited
Fisher Impulse AQ Pulse Induction Metal Detector Infographic Highlighting Key Features and Specifications
Impulse AQ Limited

Impulse AQ Limited

Fisher: Since 1931
$1,999.99 USD
{price}% OFF Sold out
Find a Dealer
Untitled_design_3_7af8c1c5-e612-43a9-9d74-845ed6bbc60f.png

Customer Reviews

Be the first to write a review
0%
(0)
0%
(0)
0%
(0)
0%
(0)
0%
(0)

Product Description

The Fisher Impulse AQ Limited is a high-performance pulse induction metal detector designed for serious beach and shallow-water treasure hunters. Built for professionals who demand maximum sensitivity in mineralized environments, it excels at locating gold and other low-conductive targets. What sets it apart is its unique combination of Pulse Induction power with advanced iron rejection and specialized beach modes.


Powered by cutting-edge PI technology, the Impulse AQ delivers exceptional depth and stability in saltwater, black sand, and other challenging terrains. With five detection modes—including All Metal, Tone, Mute, and Volcanic Sand—it adapts to changing conditions and target types with ease. Adjustable pulse delay (7–11.5 µs), ZTS® (Zero Target Separation), and HRS® (Highly Reactive System) technology enable precise, lightning-fast target detection, while advanced EMI suppression keeps performance stable in noisy environments. Its 12.5" mono searchcoil covers ground quickly and offers top-tier sensitivity to even the smallest gold items.


Engineered for durability, the Impulse AQ features a rugged build with a fully waterproof design rated to 3 feet. The adjustable shaft and balanced 4.2 lb. frame provide ergonomic comfort during long hunts, and the NiMH battery pack delivers up to 3.5 hours of runtime. Designed for harsh beach and surf use, this detector offers intuitive analog controls and a factory-sealed enclosure for long-term reliability in the most demanding environments.


Purpose: Beach Hunting, Shallow Water Treasure Hunting, Gold Jewelry Detection, Wet Sand Searching

Specifications

  • Operating Principle: Pulse Induction
  • Pulse Frequency (All Metal): 4.02 – 4.17 kHz
  • Pulse Frequency (Tone/Mute): 3.04 – 3.12 kHz
  • Pulse Frequency (Volcanic Sand): 1.54 – 1.56 kHz
  • Adjustable Pulse Delay: 7 – 11.5 µs
  • Audio Output: Headphones
  • Audio Tones: Multitone / Mute
  • Searchcoil Size: 12.5" Mono
  • Weight: 4.2 lbs
  • Length: 43 – 48 inches (adjustable)
  • Batteries: NiMH 2200 mAh
  • Battery Life: Approx. 3.5 hours
  • Waterproof Depth: Up to 3 ft / 1 m
  • Operating Temperature: -10°C to +40°C (+14°F to +104°F)
  • Iron Reject: Variable
  • Frequency Offset: Adjustable for EMI suppression
  • Target Separation: Zero Target Separation (ZTS®)
  • System Reactivity: Highly Reactive System (HRS®)
  • Sweep Speed: Adjustable
  • Sensitivity Control: Yes
  • Threshold Control: Adjustable
  • Volume Control: Adjustable
  • Warranty: 2-Year Limited
  • Stability: Excellent in wet sand, dry sand, and surf
  • Manufacturer: Fisher Research Labs (a Subsidiary of First Texas Products)
  • Brand Name: Fisher Research Labs (a Subsidiary of First Texas Products)
  • Country of Origin: USA

    • Shop

    Parts & Accesories

    Manual

    IMPULSE AQ

    Support

    For more information and to purchase, visit where to buy , email us , chat with us, or call us at 1-800-685-5050   for any questions.
    For repair service in warranty or out of warranty please fill out the RMA form.

    Videos

    Fisher Research Labs IMPULSE AQ: All Metal Mode Explained
    Fisher Research Labs Impulse AQ Assembly
    Introducing the Impulse AQ from Fisher Research Labs
    Impulse AQ from Fisher Research Labs

    Frequently Asked Questions

    Is the Fisher Impulse AQ the right detector for my needs?

    The Fisher Impulse AQ is specifically designed for serious beach hunters looking for maximum depth and performance in saltwater, wet sand, and mineralized beach conditions. If you primarily detect in parks, relic sites, or highly trashy inland areas, this may not be the ideal unit for you.

    Here’s what you get with the Impulse AQ:

    • Pulse Induction (PI) Technology – Excels in saltwater and black sand, ignoring mineralization that would cripple VLF detectors.
    • Superior Gold Detection – Optimized for low-conductivity targets like gold jewelry while still detecting high-conductive metals.
    • Waterproof Construction – Fully submersible up to 3 feet (1 meter) for shallow-water detecting.
    • 12.5” Mono Searchcoil – Provides deep penetration and broad coverage on wet and dry sand.
    • Adjustable Pulse Delay (7μs - 11.5μs) – Allows tuning for small gold pieces or larger, deeper targets.
    • Tone, Mute, and Volcanic Sand Modes – Provides flexibility for different beach conditions and target preferences.
    • Weight: 4.2 lbs – Lightweight for extended hunting sessions.

    If you’re serious about treasure hunting in challenging beach environments and want a detector that goes deeper than most, the Impulse AQ is the best tool for the job. However, if you detect mostly on dry land or trashy sites, a VLF detector with target ID and discrimination may be a better choice.

    Why is Pulse Induction (PI) superior to Very Low Frequency (VLF) in certain conditions?

    Pulse Induction is superior in mineralized conditions, such as saltwater and black sand, because it ignores mineralization while maintaining depth performance. Unlike VLF, which struggles with conductive salt and highly mineralized ground, PI operates by sending powerful pulses that measure time-delayed signal responses. This allows it to detect targets deeper without interference from ground minerals.

    How does adjusting the Pulse Delay impact detection of different types of gold targets?

    A lower Pulse Delay (around 7μs) increases sensitivity to small and low-conductivity targets like thin gold chains or small earrings. However, it also makes the detector more prone to saltwater interference. Increasing the Pulse Delay (above 10μs) filters out smaller trash and increases detection depth for larger, high-conductivity gold items like thick gold rings, but at the cost of missing very small targets.

    How does the Impulse AQ’s iron rejection differ from traditional discrimination methods?

    Unlike traditional VLF discrimination, which assigns a numerical Target ID, the Impulse AQ uses a dual-channel system where one channel is optimized for low conductors (gold) and another for high conductors (iron). The Reject and ATS controls fine-tune how ferrous targets are processed, allowing partial rejection while still producing tonal cues to experienced users, rather than a hard rejection.

    How does sweeping speed affect detection depth and target response on the Impulse AQ?

    The Impulse AQ requires a slow sweep speed for maximum depth. PI detectors process deeper signals over a longer time window, so rapid coil movement can cause the detector to miss deeper targets. A fast sweep also increases the chance of desensitization over highly conductive targets. Keeping a steady, controlled sweep maximizes performance, especially in All Metal Mode.

    Why is the Impulse AQ’s ‘Volcanic Sand’ mode necessary for extreme black sand beaches?

    Volcanic sand is highly magnetic and can overwhelm most detectors. The Volcanic Sand mode on the Impulse AQ alters the pulse timing to reject extreme levels of mineralization. However, this comes with a reduction in sensitivity to lower-conductive targets (such as small gold items), making it a necessary trade-off for operating in conditions where most detectors would fail.

    How does EMI (Electromagnetic Interference) impact the Impulse AQ, and how can it be minimized?

    EMI can cause warbling threshold tones, especially in Tone Mode. The Frequency Adjust control allows users to shift pulse frequencies slightly to find a quieter operating range. Holding the searchcoil vertically and rotating 360° can help locate the direction of EMI sources. Reducing Sensitivity and increasing Pulse Delay can also stabilize operation in high-EMI areas.

    Why does the Impulse AQ’s battery life vary significantly based on mode selection?

    The All Metal Mode consumes the most power due to constant signal processing. Modes like Mute and Volcanic Sand are slightly more efficient as they use additional filtering, reducing power draw. Running at high Sensitivity or using low Pulse Delay settings increases power consumption, while reducing Sensitivity and increasing Delay can slightly extend battery runtime.

    What are the audio cues that indicate deep or weakly conductive targets?

    Deep targets often produce soft, elongated responses, while shallow targets give sharp, well-defined signals. In All Metal Mode, targets with inconsistent or double-tone responses may be irregular-shaped iron objects. High-tone responses in Tone Mode often indicate low conductors like gold, while weak, erratic sounds could mean a small target near the detection threshold.

    Why does saltwater require different detector settings than dry sand, and what’s the best way to optimize performance?

    Saltwater is conductive and can cause false signals in low Pulse Delay settings. To compensate:

    • Start with Pulse Delay at 8 or higher to stabilize the threshold.
    • Set ATS to 8 to reduce saltwater signal interference.
    • Adjust Sensitivity downward if false signals persist.
    • Use Volcanic Sand mode if working in areas with a mix of salt and magnetic black sand.

    Is the Fisher Impulse AQ waterproof up to 3 feet for the entire unit, or only up to the battery

    The entire unit is waterproof up to 3 feet, not just the battery compartment.

    Can the Impulse AQ withstand heavy rain?

    The detector is designed to handle strong rainy conditions. As long as the cables are properly hand-tightened to the connectors, water will not enter the pins or electronics. Additional protection is not necessary.

    There have been reports of loose connector plug pins. Has this issue been resolved?

    Yes, we were made aware of this issue promptly and took immediate action to resolve it. As a process-oriented company operating under ISO 9001:2015 standards, we quickly implemented a fix to ensure quality and reliability.

    Share your story for a chance to be featured on our site! 
    Untitled_design_1_75e8c240-cd2e-4f6d-9f9b-0f153068968c
    Landon Howlett
    "...he found his first coin. A 1946 wheat. I'm glad to say we have a new Digger in the family."
    - Fisher F70
    JimDoan
    Jim Doan
    This is a Union Officers belt plate from the Civil War, it was found at a G.A.R. 1895 Civil War reunion encampment...
    - Bounty Hunter Quick Draw 2
    RyanVecchio1
    Ryan Vecchio
    "...great detector please keep me informed on the new machines coming out I got pictures of your detectors for years finding things in fields that have been hunted by everything till the first Texas hit the ground." 
    - Bounty Hunter Platinum
    JamesKSample
    James K.
    "Great contact information, wonderful interaction and the product is wonderful. I will expand my accessories, new usable work products, thanks for this convince and an all USA (EL Paso TX) buy local products." 
    - Fisher TW6