{"product_id":"oled-pen-frequency-meter-200hz-100mhz-rf-counter","title":"OLED Pen Frequency Meter 200Hz–100MHz | High-Precision RF Counter","description":"\n\u003ch2\u003e200Hz–100MHz Pen-Type Frequency Meter with 0.91\" OLED Display\u003c\/h2\u003e\n\u003cp\u003eThe \u003cstrong\u003ePLJ-091OLED-L1 Frequency Meter Pen\u003c\/strong\u003e is a compact, high-precision RF frequency counter built for electronics engineers, hobbyists, and radio enthusiasts who demand accurate, real-time frequency readings. Featuring a crisp \u003cstrong\u003e0.91-inch blue OLED screen\u003c\/strong\u003e and a dedicated \u003cstrong\u003eSJ8K24P-T measurement chip\u003c\/strong\u003e, this pen-style instrument delivers measurement accuracy down to \u003cstrong\u003e1Hz\u003c\/strong\u003e across a wide range of \u003cstrong\u003e200Hz to 100MHz\u003c\/strong\u003e — making it an indispensable tool for RF testing, MCU oscillator verification, and wireless device calibration.\u003c\/p\u003e\n\n\u003cp\u003eMade in Mainland China.\u003c\/p\u003e\n\n\u003ch3\u003eKey Features\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eHigh-Precision Dedicated Chip:\u003c\/strong\u003e The SJ8K24P-T chip delivers measurement accuracy of 10Hz or 1Hz, ensuring stable and reliable performance across all supported frequencies.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eTemperature-Compensated Crystal Oscillator (TCXO):\u003c\/strong\u003e A built-in ±2.5ppm TCXO ensures excellent frequency stability, making this meter suitable for precise, professional-grade frequency measurement.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e0.91\" Blue OLED Display:\u003c\/strong\u003e Bright, high-contrast display shows up to 8 digits for clear, real-time frequency readings — even in low-light environments.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSwitchable Unit Display:\u003c\/strong\u003e Instantly toggle between MHz, KHz, and Hz display modes with the K2 key for fast identification of frequency values.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCompact Acrylic Shell:\u003c\/strong\u003e Pen-form factor with high signal sensitivity makes this meter easy to carry and ideal for on-site high-frequency detection.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eAuto Memory:\u003c\/strong\u003e All user settings are saved automatically when powered off and restored instantly on startup — no reconfiguration required.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eUSB Type-C Power Interface:\u003c\/strong\u003e Modern, reversible Type-C connector for easy, reliable power connection (DC 4.5–5.5V; 5V recommended).\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003ctable\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMeasurement Range\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e200Hz – 100MHz\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMeasurement Accuracy\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e10Hz \/ 1Hz\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eFrequency Stability\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e±2.5ppm\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eGate Time\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e0.1s \/ 1.0s\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003ePower Supply\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eDC 4.5–5.5V (5V recommended)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eOperating Current\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e~30mA at 5V DC\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eDisplay\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e0.91-inch OLED (up to 8 digits)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eInterface\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eUSB Type-C\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eShell Material\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eAcrylic\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch3\u003eIdeal Applications\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003eVerifying and calibrating crystal oscillators in MCU \/ single-chip microcomputer systems\u003c\/li\u003e\n  \u003cli\u003eTesting and evaluating wireless communication equipment and radio transceivers\u003c\/li\u003e\n  \u003cli\u003eCalibrating signal and frequency generators\u003c\/li\u003e\n  \u003cli\u003eEvaluating communication port output timing reliability\u003c\/li\u003e\n  \u003cli\u003eGeneral RF signal measurement and troubleshooting in the field\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eImportant Usage Notes\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003eThe signal ground connection uses only the shielding layer of the shielded wire — the inner core is not connected to ground.\u003c\/li\u003e\n  \u003cli\u003eDo \u003cstrong\u003enot\u003c\/strong\u003e use fast-charging adapters, as they may output voltages higher than 5V and could damage the device.\u003c\/li\u003e\n  \u003cli\u003eWhen a signal exceeds 100MHz in MHz or KHz display mode, the leading digit \"1\" may not display. Switch to Hz mode (press K2) for a full readout.\u003c\/li\u003e\n  \u003cli\u003eColor may vary slightly from product images due to display and lighting differences. Dimensions allow ±1mm–1cm variance due to manual measurement.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat's in the Box\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e1× Frequency Meter Pen (PLJ-091OLED-L1)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eFor further reference on RF measurement standards and electronic test equipment safety, visit the National Institute of Standards and Technology (NIST) – Electrical Measurements.\u003c\/p\u003e\n\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003ch4\u003eQ: What is the measurement range of this RF frequency meter pen?\u003c\/h4\u003e\n\u003cp\u003eA: This frequency counter measures signals from \u003cstrong\u003e200Hz up to 100MHz\u003c\/strong\u003e, covering a wide range of RF and digital signals used in radio transceivers, MCU oscillators, and communication equipment.\u003c\/p\u003e\n\n\u003ch4\u003eQ: What power supply does the frequency meter pen require?\u003c\/h4\u003e\n\u003cp\u003eA: The device operates on \u003cstrong\u003eDC 4.5–5.5V\u003c\/strong\u003e via a USB Type-C interface. A standard 5V USB power supply is recommended. Do not use fast-charging adapters, as they may output voltages that exceed the safe operating range.\u003c\/p\u003e\n\n\u003ch4\u003eQ: Why doesn't the display show all digits when measuring above 100MHz?\u003c\/h4\u003e\n\u003cp\u003eA: The 0.91-inch OLED screen supports up to 8 digits. When the measured frequency exceeds 100MHz in MHz or KHz display mode, the leading digit \"1\" may be cut off. Simply press the \u003cstrong\u003eK2 key to switch the display unit to Hz\u003c\/strong\u003e for a complete, full-digit readout.\u003c\/p\u003e\n\n\u003ch4\u003eQ: Does the device retain my settings after being powered off?\u003c\/h4\u003e\n\u003cp\u003eA: Yes. The frequency meter pen features \u003cstrong\u003eautomatic settings memory\u003c\/strong\u003e. All configurations — including display unit preference and gate time — are saved automatically when the device is powered off and restored immediately upon startup.\u003c\/p\u003e\n\n\u003ch4\u003eQ: Is this frequency counter suitable for testing radio transceivers?\u003c\/h4\u003e\n\u003cp\u003eA: Absolutely. The ±2.5ppm temperature-compensated crystal oscillator and 1Hz measurement accuracy make this meter well-suited for testing and calibrating radio transceivers, verifying oscillator frequencies, and evaluating RF signal sources across the 200Hz–100MHz range.\u003c\/p\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e{\"@context\": \"https:\/\/schema.org\", \"@type\": \"FAQPage\", \"mainEntity\": [{\"@type\": \"Question\", \"name\": \"What is the measurement range of this RF frequency meter pen?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"This frequency counter measures signals from 200Hz up to 100MHz, covering a wide range of RF and digital signals used in radio transceivers, MCU oscillators, and communication equipment.\"}}, {\"@type\": \"Question\", \"name\": \"What power supply does the frequency meter pen require?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"The device operates on DC 4.5–5.5V via a USB Type-C interface. 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