The γDog Scintillation Radiation Detector
The γDog is a highly optimized, ruggedized field instrument specifically engineered for maximum comfort and efficiency while prospecting for anything radioactive. Conceived and developed by Charles David Young, the device overcomes the limitations of slow-responding Geiger counters when hunting for buried or low-activity specimens by leveraging gamma sensitivity, an instantaneous fast response rate, and an advanced relative audio feedback system.
Hardware Architecture & Sensitivity
Unlike typical pocket meters with small integrated crystals, the γDog uses a high-performance external NaI scintillation probe to maximize field search efficiency.
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Bicron 38B57 Probe Optimization: The standard system is built around the Scionix-Holland / Bicron 38B57 probe assembly, utilizing its substantial 1.5" x 2.25" Sodium Iodide—NaI(Tl)—scintillation crystal. This crystal volume provides a high raw count rate (yielding 100–120 CPS at a typical natural background level) to map deep or faint gamma-ray signatures under several inches or even feet of soil and rock.
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Weather-Resistant PETG Enclosure: Both the round and square control module housings are 3D-printed using heavy-duty PETG filament, offering durable physical shock and weather resistance suited for rugged field abuse.
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Ergonomic Handle & Strap: The handle is specifically designed to make the unit easy to carry and manipulate while digging a hole, featuring integrated notches for a sling strap so you can easily skim the probe right along the ground to find the faintest hotspots.
Advanced Squelch & Relative Audio System
Instead of forcing the user to interpret standard, slow-integrating "clicks" or constantly check a screen, the γDog uses a variable-pitch tone system tailored to the limits of human hearing, allowing for completely eyes-free operation.
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Squelch-Controlled Audio: Training the γDog consists of setting the squelch, which keeps the device relatively quiet when there is just background radiation. The audio becomes noticeably more active when the radioactivity exceeds the squelch, indicating a localized hot spot may have been found.
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Dynamic Tone Generation: Once the radiation count rate exceeds your current squelch, the speaker emits a clean tone whose pitch is proportional to the net count rate. The higher the radiation count rate, the higher the pitch. Small variations are mapped exponentially—an increase of just 30 to 50 CPS above your background causes a massive, unmistakable jump in pitch, allowing the human ear to readily discern tiny fluctuations as small as 5 CPS.
Field Gestures & Operation Modes
The γDog features a minimalist physical interface consisting of two buttons with status LEDs, an on/off switch, and an internal speaker. It handles setup and mode adjustments entirely via internal orientation sensors using intuitive hand gestures:
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Manual Background Sampling: Placing the dog horizontally (with the handle up) and rolling it 90 degrees to one side samples your local environment and locks the squelch, confirmed by two short beeps.
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"Open" vs. "Closed" Squelch: The first roll sets a "Closed" squelch slightly above background for total silence. Immediately rolling the handle back to vertical and back to 90 degrees toggles it to an "Open" squelch slightly below background, letting you hear continuous, faint audio variations.
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Nudge Adjustment: After setting the squelch but before rolling it upright, rolling the unit up about 45 degrees and back to 90 degrees steps the squelch threshold slightly higher.
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Automatic Squelch Mode: Toggled by pointing the nose of the γDog directly at the sky for about 10 seconds. In Auto Mode, the internal software constantly measures the background over a 30-second window to keep the unit sensitive but stable. When set properly, the dog will "growl" occasionally while walking but won't chatter constantly. Auto-mode can be manually set the squelch by simply laying the dog horizontally on the ground while on its strap (if your unit has the GPS upgrade installed, point the nose straight down for a few seconds before laying it flat).
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Inactivity Quiet State: If the dog goes silent after a period of inactivity, simply move the instrument to reactivate the high voltage relay.
Wireless Data & Spectroscopy Features
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Bluetooth Telemetry Logging: The built-in Bluetooth transmitter pairs with the standard Bluefruit Connect application on iOS or Android. Selecting the UART option lets you view real-time operations (including live CPS, squelch configurations, and battery levels).
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ySpec Field Spectroscopy: The control board contains an integrated pulse shaper that outputs pulse-height spectroscopy data wirelessly over Bluetooth. By issuing terminal commands, you can run a field spectrum collection and export a clean data array to spreadsheets (like Excel or Google Sheets), making it simple to visually distinguish between Thorium (Th-232) and Uranium (U-238) decay strings right in the field.
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Console Command Suite: Typing
?into the UART terminal screen pulls up the configuration menu. Primary field commands include:-
q: Toggles the 1-second interval live scrolling status text output on/off (audio tones automatically mute while text streaming is active). -
u [count]: Sets the squelch [optionally to a specific count] -
h [#]: ySpec: 1.collect [spread 1-2] 2.print [0=pause 1=mca] -
x: Toggles the Gamma Spectroscopy pulse-pileup suppression routine on/off (recommended to leave on). -
n [text]: Programs a custom alpha-numeric broadcast name into the Bluetooth module for easy identification on your phone.
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Acoustic Diagnostic Matrix
The device communicates its internal status, battery life, and high-voltage states using distinct acoustic signatures:
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Startup Battery Telemetry: Upon initial power-on, the device emits a rapid sequence of short diagnostic beeps to signal its charge state: 1 beep 75%, 2 beeps 50%, 3 beeps 25%, and 4 beeps (critically low, past time to charge).
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High-Voltage Status Cascades: A rapid falling pitch sequence indicates that the high-voltage power supply to the Photomultiplier Tube (PMT) has been disabled (occurs at startup or when the unit goes quiet from inactivity). A slow rising pitch sequence indicates that high voltage has been enabled and the probe is live.
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Squelch Tone Indicators: A low-to-high double beep denotes an elevated squelch threshold, while a high-to-low double beep denotes a lowered threshold. A pair of long tones separated by an octave signals a shift between Manual and Automatic modes.
Power & Field Charging
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Dual 18650 Battery Setup: Powered by premium Lithium-ion batteries that can be easily replaced by the owner if necessary, providing a massive capacity designed to handle a full days of field prospecting.
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The Power-On Charging Rule: Charging the internal cells requires unscrewing the protective, captive USB cap located on the rear enclosure. The physical power switch must be flipped to the ON position to charge. While the dog will initially emit tones like it is active when plugged in, the high voltage will be switched off after a period of inactivity.
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High-Voltage Charging Protection: While plugged in and remaining completely immobile, standard non-GPS units automatically deactivate the high voltage to the probe for safety (units equipped with the custom GPS configuration keep the high voltage active).
NOTE: By purchasing this item, you agree that you have read our Terms and Conditions (which also serve as Warnings and Notices).