B&K Precision, represented in Australia by Unispan Instruments , has released the 1856D lightweight frequency counter. It is capable of frequency measurements from 0.1Hz to 3.5GHz for a range of laboratory and service applications.
It has a revolutions per minute measuring function, an external frequency standard input with a nine-digit LED display, an attenuator, a low-pass filter and a line filter. It has a 50W-terminated input for use in high-frequency VHF/UHF/microwave/mobile telephone systems, as well as a standard 1MW input for frequency measurements up to 100MHz. The counter uses a nine-digit display, which provides up to 10nHz resolution to 3.5GHz, 1Hz resolution to 100MHz, and 0.1Hz resolution to 10MHz.
In period mode, the unit measures the period required (in microseconds) for one cycle, over the range of 5Hz to 3.5MHz. At low frequencies, much greater accuracy can be achieved by period measurement than by frequency measurement.
Totalise mode permits the counting of individual events. The counting process can be gated, either manually by a front panel switch, or by a gating signal applied to a rear panel jack, for more exact electronic control.
Front panel push-button switches select the operating mode and one of four decades of resolution. Readouts are provided by large, bright digits, automatic decimal point placement, leading zero blanking, and LED display of proper measurement units. Over range and gate functions (indication of a measurement in progress) are also shown on front panel indicators.
A front panel hold switch is provided which freezes the display at the present reading. A reset button clears the counter display and initiates a new measurement when released. A selectable X10 attenuator and selectable 100KHz low-pass filter are incorporated at the standard frequency input jack, for lessened susceptibility to noise and (in low frequency measurements) undesirable high frequency components.
The 10MHz time base is generated by a temperature-compensated crystal oscillator (TCXO) for stability with regard to temperature (±1ppm, 0°C to 40°C), and line voltage variation (0.1ppm for ±10% variation). Other features include universal ac capability, a multi-position carrying handle/tilt stand for portability, and internal RF shielding.
It measures 88.9mm x 10.269.24mm x 238.76mm and weighs 2.497kg. It comes with an operating manual and a line cord.