The current consumption of SATELLINE-1ASl ja -1AS varies between 50 ... 250 mA and of
SATELLINE-2AS and -2ASx between 100 ... 600 mA. In systems where models
SATELLINE-1ASl or -1AS have been changed to models SATELLINE-2AS tai -2ASx , current
supply has to be checked. Especially in portable applications the DTR line of the radio
modem should be switched to position "0" when possible. In this case the current
consumption is approx. 0.2 mA (SATELLINE-1AS and -1ASl) or 3 mA (SATELLINE-2AS and
-2ASx). In mobile use the radio modem is required to have a direct connection to the main
vehicle battery in order to avoid additional interference.
NOTE POWER SUPPLY !
Even if the nominal output current of the power supply does not exceed it might
temporarily be unstable as the current consumption changes e.g. at starting the power
amplifier. The outputs of power supplies are often supplied with sufficient output
capacitance. The output capacitance of self built power supplies with regulators or
switched-mode power supplies might be insufficient or totally lacking.
Even if the nominal output current is considerably higher than the current consumption
of the radio modem, the voltage varies several voltages according to the changes of
the current consumption of the radio modem. This kind of function of the power supply
weakens the function of the radio modem or prohibits it totally.
Supply current should be controlled in situations where the distance is short or the
radio field strength is sufficient but the connection does not work or the number of
faulty packets is big. Quick changes in voltage can not be measured with a multimeter
as they often last for only approx. 0.5 ms. Therefore possible situations with
undervoltage should be surveyed with an oscilloscope. To ensure a reliable operation
of the radio modem the acceptable variation is below 1 V from the stable level and
continuous oscillation below 50 mV.
NOTE!
Whenever connecting RS-232 interface cables to equipment, the
equipment MUST FIRST BE SWITCHED OFF.
5.3
Mounting the antenna
In great distances or in otherwise severe conditions the operation of radio communication
is dependent on antennas and their mounting. In antennas, antenna cables and terminal
adaptors there should always be a gold plated connector. Since connectors of poor quality
oxidate and increase the attenuation in the course of time appropriate connectors and
proper tools must always be used in mounting. One should also check that both the
antenna and possible fitting elements resist well weather and environmental contamination.
SATELLINE-1AS and SATELLINE-2AS
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