Low-cost Frequency Counter from TTi operates to 3GHz

Despite its compact size and low cost, the PFM3000 incorporates several advanced features. It uses the ‘reciprocal counting’ measurement technique to achieve high measurement resolution at all frequencies. The system yields up to 8 digits of resolution per second of measurement time, and can resolve low frequencies to 0.001mHz (0.000001Hz).

Two measurement ranges are provided. Range A covers from below 3 Hz to above 125 MHz via a high impedance input. Range B covers from below 80 MHz to above 3000 MHz via a 50 ohm input. Sensitivity is typically better than 15 mV across the range, rising to 25 mV at 2.5 GHz and 50 mV at 3 GHz.

Period measurement is provided for signals in the range from 8 ns to 330 ms. A selectable low-pass filter is provided to reduce the noise on lower frequency signals. A ‘hold’ key allows readings to be frozen on the display whenever required.

Low power consumption circuitry ensures long battery life, and a ‘push to measure’ facility is also incorporated. This provides an immediate reading on the press of a key followed by an automatic power down after 15 seconds, thus ensuring maximum battery life when continuous signal monitoring is not required.

The PFM3000 is housed in a robust ABS case measuring 81 x 173 x 30mm (7 x 3 x 1.2 inches) and weighing less than 200 g (7 ounces). A large LCD display of very high contrast with 11.5mm high characters is incorporated. The display incorporates 15 annunciators covering measurement function, measurement time, units, overflow, trigger activity and low battery.