Racal 1991 Frequency Counter

Frequency, Period, Time Interval, Ratio, Totalize, Phase, and Peak Amplitude measurements are all possible with the 1991 2-Channel Universal Timer/Counter. Also, it's ready to use as an integral part of an Automatic Testing Equipment Station. Front panel buttons are conveniently grouped by function and LEDs indicate when you're communicating through the GPIB port, when the 1991 is gating, and when the 1991 requests service, plus a HOLD button for fluctuating displays. It can even temporarily store information for later retrieval. Frequency range from DC to 160MHz; Channel A's sensitivity is 25 mV rms up to 100MHz, >100MHz, it triggers on 50 mV rms to 160MHz; Channel B has same sensitivity as Channel A except that the frequency range is 10Hz to 100MHz. 9-digit display offers the resolution required to make accurate measurements. The 1991's other outstanding features include auto-triggering and attenuating, direct digital trigger entry, comprehensive external arming, time-interval delay, extensive math functions plus offsetting and normalization capabilities.