Casella CEL Nomad portable weather station - Manual (Page 61)

General facilities +5 V output
Analogue and digital inputs
Direct TT500 replacement.
8.4.2 Low Power Radio Receiver Specification
Frequency range 458.5 to 458.6 MHz (8 channels)
Frequency stability ±2 ppm
Number of RF channels RS232 or 1 of 8 parrallel select
Channel switching delay <50mS across switching bandwidth
Channel spacing
12.5 kHz
Modulation type F1D/F2D/F3D
Spurious emissions
conducted & radiated In accordance with ETSICEPT specifications
Supply voltage 6-15 DC, -ve earth
Supply current at 7.2 V <40 mA
Interface connections 2- and 10-pin 0.1" header
RF connection 3-pin 0.1" header
Operating temperature -20°C to +55°C
Storage temperature -30°C to +70°C
Weight 35g
Size 60 x 39 x 15 mm
2.36 x 1.53 x 0.59 inches
Type approval MPT1329
Sensitivity <-115 dBm for 12 dB SINAD (12.5 kHz)
<-117 dBm for 12 dB SINAD (25 kHz)
(Measured with a flat audio response)
Image/spurii >60 dB
Intermodulation response
rejection >60 dB
Blocking >75 dB
Intermediate frequencies 45 MHz and 455 kHz
Adjacent channel
selectivity >60 dB for 12.5 kHz channel spacing
>70 dB for 25 kHz channel spacing
Audio response 9 Hz to 6 kHz at -3 dB (25 kHz channels)
Recovered audio level >250 mV p-p (±20%) into 10 k
Ω
Squelch type Noise operated open collector output
General facilities RSSI output (0.5 to +2 V nominal)
+5V output
Independent data output
8.5 GSM Link
Casella CEL can supply a GSM
modem (Global System for Mobile
communications) that
communicates via the GSM mobile
phone network. This arrangement
allows continuous two-way
communication, with control and
data download as described in
Chapter 3.
Please remember that
the GSM link operates via a
commercial carrier, so that
although continuous on-line
Communication
Figure 26: The GSM modem
Page 61 of 68
NOMAD Portable Weather Station
Users Handbook