The digital field strength meter (FSM) is a compact, battery-powered device to assess reception at the planned installation site of an AM modulated long-wave receiver.
Using the built-in ferrite antenna, the signal strength of the existing time signal is measured and the measured value is displayed in [dB µV/m] on the LCD. A conversion table in [µV m] printed on the back of the device supports interpretation of the field strength values.
At the same time the quality of the received signal is measured and reported as a quality index in the range of 0 (not usable) to 6 (very good) on the LCD.
The prospect of successful signal reception can be determined by evaluating the combination of the information on the prevailing signal field strength and the bit quality.
Thus, the FSM is an ideal tool for the preselection of a suitable installation location or for the proper alignment of a time signal receiver (or its antenna) to the transmitter.
An FSM is available in each device version for the worldwide active AM time signal transmitters DCF77, MSF, WWVB, JJY and BPC.
The JJY version is designed as a 2-band receiver and can switch between the 2 carrier frequencies (40kHz and 60kHz) to switch between the JJY Japanese time signals. The other device versions are 1-band receivers.