Meinberg FM614 - Manual (Page 5)

5
General information about position of antenna
The antenna of DCF-receivers includes a ferrite rod which must be aligned to the
transmitter. For best receiption the longitudinal side of the antenna must point to
Frankfurt. The antenna should be installed with a distance of at least 30cm to all metal
objects because they would detune the antenna resonance. A distance of several meters
to computer monitors must be kept. If they are running in a high screen resolution
mode, their line frequency is close to the carrier frequency of the DCF-transmitter,
which would cause a worse or no reception.
Features of FM614
The FM614 has been developed to help service technicians in finding the best
possible position for installing a DCF antenna or receiver module.
It includes two synchronous demodulators for the DCF-signal. One signal path
detects the field strength of the 77.5 kHz-signal at the output of the antenna, the
second receiver circuit demodulates the timing marks. The determined signal level is
indicated by an analog display, the timing marks are made visible by a LED and can be
observed acoustic by a piezo buzzer.
The FM614 is designed for both AC-line and accu supply. During AC-supply the
internal accus are charged. This state is signalled by a LED, overcharging is not
possible. If the FM614 often runs in accu supply mode, the accumulators should be
discharged (unplugg power supply cable and switch into accu supply mode) at times to
avoid the loss of capacity. The status of capacity can be checked with the help of the
analog display.
The scope of supply includes an active ferrite antenna AI01, a AC-power cord and a
coaxial antenna cable (RG174).