Commercial In Confidence
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4.1
INTRODUCTION
The ART Series are DIN rail mountable Radio Modems/Repeater for outstation applications,
although with the upgraded internal heat sink they could be used as base station/scanners,
providing the transmit duty cycle is less than 75%.
Correct installation should ensure reliable data communications for many years.
The most important installation points to remember are:
Suitable antenna system mounted at the correct height & polarisation to achieve the required
distance.
Reliable power supply capable of supplying the correct voltage and current.
Correct installation for the environment
Correct interface and set-up
Assuming the unit has been correctly installed and tested at the correct data speed, the only
other factors that will effect the performance, are the RF power, (Normally Specified by the
regulating authority), the local topography and the weather, none of which the user can
control.
4.2 POWER SUPPLIES
The ART series can be powered from any power source providing the voltage is between
9.6VDC & 15VDC –VE GND. If a +VE GND system is in use, an isolated converter will be
required.
The ART Series is available in either 10mW – 1Watt or 20mW – 5Watts, which requires a
supply current of 1Amp and 2.5Amps respectively.
Under no circumstances should the output of the supply rise above 16VDC.
For 240/110VAC, 50VDC or 24VDC, R.F. Technologies produce a range of uninterruptable
power supply units with an in-built charger and power fail indication. A range of suitable
Gel type batteries is available should a back-up supply be required during power fail.
ART DIN Power Supplies:
ART750
80- 250VAC to 12VDC 3 Amps with backup battery charger & fault
reporting via the I2C Bus
ART751
18 – 60VDC isolated to 12VDC 3 Amps with backup battery
charging and fault reporting via the I2C bus
4.3
EFFECTIVE RADIATED POWER (ERP)
The Radio Frequency (R.F.) Power allowed can be specified in two ways:
The “Terminated power into 50 ohms”, which in the case of the ART 5watt product would
be a maximum of 5Watts.
The “ERP” is the actual radiated power, taking into account the gain/loss of the antenna and
loss in the feeder. Hence, if we use an aerial with a Gain of 3dB (x2) and assume no loss in the
cable, the ERP with an input of 5watts would be 10Watts.
The gain of an antenna is very useful as it enables lower power transmitters to be used
in many cases in place of high power transmitters, with the advantage of a much lower
current consumption.
