Fluke 1953A Counter Timer 125MHz 9-Digit LED Freq Ratio Period Measurements

Fluke 1953A Counter Timer 125MHz 9-Digit LED Freq Ratio Period Measurements

The Fluke 1953A is a benchtop universal counter/timer covering DC to 125 MHz with a bright 9-digit LED display and 1 Hz frequency resolution. It provides a full set of measurement functions — frequency, frequency ratio, period, time interval, and gated totalize — in a single compact instrument suited to calibration labs, production test benches, and general RF/electronics work. This unit came directly from an electrical engineer's professional calibration and product development lab.

Specifications & What's Included

• Frequency range: DC to 125 MHz
• Sensitivity: 30 mV
• Display: 9-digit LED with MHz, KHz, ms, µs, sec, Overflow, and Remote annunciators
• Frequency resolution: 1 Hz
• Gate time: 0.1 ms, 1.0 ms, 10 ms, 0.1 s, 1.0 s, 10 s (selectable via front-panel Range knob)
• Time resolution: 0.1 µs to 10 ms (selectable)
• Measurement functions: Freq A, Freq C, Freq A/B (ratio), Period A, Time Interval A–B, A Gated by B, Self Check
• Channel A: DC to 125 MHz, 1 MΩ / 50 Ω input impedance (selectable), X1/X10 attenuation, adjustable trigger level and slope
• Channel B: DC to 25 MHz, adjustable trigger level and slope, X1/X10 attenuation
• Channel C (option): 50 MHz / 520 MHz, 50 Ω, 5 V RMS max (BNC input visible on front panel)
• Remote control: Remote/Cycle Rate front-panel input with INC switch
• Mode: Continuous / Triggered (front-panel Mode switch)
• Form factor: Benchtop
• Rear panel: BNC connectors, IEC AC inlet, heat sink fins
• Unit only — no manual or accessories included

Applications

Universal counter/timers like the Fluke 1953A are standard instruments in electronics calibration labs, RF design benches, and production test environments. They are used to measure the precise frequency of oscillators, crystal resonators, signal generators, and clock circuits; to time interval measurements between two events on separate channels; and to perform frequency ratio comparisons between two signals. The 1953A dates from the late 1970s to early 1980s, an era when Fluke produced a well-regarded line of benchtop counters that competed with HP and Racal instruments on accuracy and build quality. Its 125 MHz upper range and selectable 50 Ω / 1 MΩ input make it useful across a wide range of RF and low-frequency work. These counters remain highly practical today for anyone maintaining vintage lab equipment, calibrating signal sources, or working with legacy instrumentation that predates PC-based measurement systems.