SATELLINE-3AS(d) Epic

Powerful radio modem with diversity reception

• RS interface data speed 300...38400 bit/s
• Interfaces RS-232, RS-422 or RS-485
• LCD display and four push buttons in 3ASd Epic
• Error correction (FEC)
• Repeater function
• Programmable output power 1 W...10 W
• Frequency tuning range +/-2 MHz from the central frequency

High-Speed UHF Radio Modem with 10W Output Power and Diversity Receiving

Radio modem SATELLINE-3AS Epic includes a high power (10W) transmitter and two receivers which gives you numerous diversity functions. Due to the powerful transmitter the coverage is better than before and the distances between the stations can be remarkably longer. With the diversity receiver the modem selects the best signal from the ones received in distinction to the two different points. Thus we can improve the reliability of the connection where there is a lot of reflections and fading. These new characteristics make it possible to more than double the distances between the modems compared to the existing SATELLINE-3AS radio modems.

Diversity Reception

In radio systems it is not necessary to have a direct visual connection between the master station and the moving substation because the radio signal transmits by reflecting from buildings and terrain e.g. such as hills. The fading occurs when the radio signals reflect from several objects to the antenna of the receiver. The propagation speed of the radio signals is at the speed of light so the signals reflecting from different objects arrive into the receiver at different times. The signals at the receiving antenna are in different phases so in the worst case two equally strong signals being in opposite phases cancel each other out and thus will cause the fading. The dips of the signal appear with half wave intervals. In connections, which are only based on reflections, the reliability of the signal receiving is depending on the position of the receiving antenna even ones fairly close to the base station.

By setting the two antennas of the diversity receiver at least ¾ x wavelength apart from each other the message can always be received by one of the receivers if not both. When installing the antennas in this way they are rarely at the same time in the fading dips.

Dual Band Version

The SATELLINE-3AS(d) Epic modem is available also as a "Dual Band" version. The transceiver of the radio modem offers as an option two 2 MHz frequency bands, tuned at the factory with a maximum separation of 15 MHz between the highest and the lowest frequency. The radio modem can be reprogrammed to operate at any channel within those two bands.