Powerful High Speed 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
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 ѕ 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.
Specifications:
|
TRANSCEIVER |
|
Frequency range |
400 ... 470 MHz |
|
Channel spacing |
12.5 / 25 kHz |
|
Communication mode |
Half-duplex |
|
Transmitter |
|
Carrier power |
1 W ... 10 W / 50 ohm |
|
Receiver |
|
Sensitivity |
-116 ... -110 dBm (BER < 10 E-3) |
|
Adjacent channel selectivity |
> 60 dB /> 70 dB |
|
Diversity scheme |
Space diversity, selection combining |
|
DATA MODEM |
|
Interface |
RS-232 or RS-422. RS-485 |
|
Interface connector |
D 15, female |
|
Data speed of RS interface |
300 - 38400 bps |
|
Data speed of radio interface |
19200 bps (25 kHz channel) |
| 9600 bps (12,5 kHz channel) |
|
Data formats |
Asynchronous data |
|
GENERAL |
|
Operating voltage |
+11.8 ... + 30 Vdc |
|
Power consumption |
3 VA typical (receive) |
| 25 VA typical (transmit) |
| 0.05 VA typical (when DTR is "0") |
|
Temperature range |
-25°C ... +55°C |
|
Antenna connector |
TNC, 50 ohm, female |
|
Construction |
Aluminium enclosure |
|
Size H * W * D |
151 * 123 * 31 mm |
|
Weight |
550 g |