Meinberg RU226 - Manual (Page 2)

FUNKUHREN
RU226
DCF77-receiver
Antenna
Generally, the exact mounting of the antenna is important. It has to be placed in longitudinal
direction to the transmitter (Frankfurt). The antenna should be installed with a minimum distance
of 30cm to all metal objects. A distance of several meters to TV- or computermonitors should be
kept. The vicinity of computers or microprocessors must be avoided. Adjustment of the antenna
can be done by watching the LEDs. But: a large field strength on its own is no guarantee for good
conditions of receiption, because interfering signals within the bandwidth of the receiver also have
an effect on the brightness of the 'field'-LED. Therefore, only undisturbed pulses per second
together with a high field intensity is a criterion for good receiption of the DCF-signal.
Power supply
The receive module needs a 3,5 V to 5,5V power supply. This voltage should be sourced by a
linear regulated power supply. If the use of a switched mode power supply becomes necessary the
GND access of the RU226 has to be grounded directly or via a capacitance of min. 0.1µF. This
connection avoids the signal-to-noise ratio reducing influence of the harmonics of the switched
mode power supply.
Polarity of the pulses
If the cover of the case is removed, a jumper becomes accessible. The position of this jumper
decides on the polarity of the output signal. The selection of high-active (default) or low-active
pulses is possible.
Jumper Jumper
Output signal