Use Manual

DMR repeater 24/01/2011 Versione 1.3

Documento Riservato - non divulgabile senza autorizzazione

Pag. 31 / 31

∞ voltage polarity, used to supply the optically isolated digital input contacts: inside PSU module, a 4

poles dip-switch allows to set the polarity, according the following table:

1 ON

2 ON

3 OFF

4 OFF

+12V

1 OFF

2 OFF

3 ON

4 ON

-12V

∞ AF line interface characteristics: inside I/O module, a 2 pole dip-switch allows to set the line type (2W

or 4W) and the input impedance of eventual 4W line (600 ohm or high), according the following table:

1 ON

Zin (4W) = 600 ohm

1 OFF

Zin (4W) = High

2 ON

2 OFF

5.3.7 SELF-CALIBRATION PROCESS

During self-calibration process internal parameters of modulator and demodulators are tuned by generating a

signal through the synthesizer of the transmitter, by automatically connecting its output to the input of the

receiver and by analyzing the received signal. If a strong signal is received by the external antenna during self-

calibration, it is possible that the process ends with errors (a corresponding “warning” alarm will be displayed

on both frontal leds and monitor of PC for remote control). In this case the DSP will load from flash memory

the previously saved parameters without any problem for the transceiver.

To obtain better results from self-calibration process, it is recommended to set the calibration frequency as

near as possible to the transmitter frequency; if there is a range of allowed frequencies for transmission, it is

recommended to set the centre of this range as the calibration frequency.

5.3.8 PPS SIGNAL

For applications in simulcast networks where the source of synchronization is the PPS signal by GPS, if this

signal is missing, the radio coverage of the areas which are reached by several repeaters with the same field

strength, is not ensured. Attention must be paid in choosing and placing the GPS antenna.