Tektronix CMC251 Frequency Counter

• Channel A
  • Frequency Range - 1 Hz to 100 MHz.
  • Sensitivity - 20 mVRMS, 1 Hz to 30 MHz; 50 mVRMS, 30 MHz to 100 MHz.
  • Attenuation - 3 V to 42 V (HI); 50 mV to 5 V (LO).
  • Max. Input Voltage - 1 Hz to 5 MHz: 42 V pk. 5 MHz to 100 MHz: 4.9 V pk.
  • Low Pass Filter - -3 dB at 100 kHz.
  • Impedance - 1.0 MΩ, paralleled by 40 pF.
• Channel B
  • Frequency Range - 80 MHz to 1.3 GHz.
  • Sensitivity - 5 mVRMS, 80 MHz to 600 MHz; 15 mVRMS, 600 MHz to 900 MHz; 35 mVRMS, 900 MHz to 1.3 GHz.
  • Impedance - 50 Ω.
  • Max. Input Voltage - 1 VRMS.
• Period
  • Range - Direct: 0.4 µs to 1.0 s. Prescale: 0.04 µs to 1.0 s.
  • Resolution - Direct: 100 ps to 100 ns. Prescale: 10 ps to 10 ns.
  • Min. Pulse Width - Direct: 0.2 µs. Prescale: 20 ns.
  • Frequency Range - Direct: 1 Hz to 2.5 MHz. Prescale: 1 Hz to 25 MHz.
  • Events Averaged (N) - 1, 10, 100, 1000, 10,000 cycles.
  • Totalize Range - 0 to 99,999,999.
• Pulse Width
  • Range - 0.25 µs to 0.5 s.
  • Period Range - 100 ps to 100 ns.
  • Events Averaged (N) - 1, 10, 100, or 1000 cycles.
• Time Base Stability
  • Temperature - <1 ppm from 0 °C to 40 °C.
  • 10% Line Voltage Change - <0.4 ppm.
• Accuracy
  • Frequency - ±(time base error + 1 count).
  • Period - ±(time base error + 1 count + trigger error).
  • Pulse Width - ±(time base error + 1 count + trigger error + 10 ns).
• Plus
  • Selectable Slope - No.
  • Ratio CH A: CH B - No.
  • Display Hold - Yes.
  • Remote Start/Stop - Yes.
  • Time Interval CH A: CH B - No.
  • Safety - UL1244, CSA231, EN61010-1.
  • EMC - Meets Directive 89/336/EEC.

• Training
• Manufacturing
• Production Test
• Field Repair
• Bench Calibration and Repair
• Product Design
• Laboratory and Research
• Education

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