ADI AR-147 User Manual page 9

4-2-2 Fixed Station
A regulated DC power supply (13.8 VDC capable of supplying at less
11 Amperes) is required.
1. Never connect the AC power cable to the AC until all other
connections have been made.
2. Before connecting and disconnecting the power connector, be
sure to turn OFF the POWER switches of both the transceiver
and the DC power supply.
3. Observe polarity of the DC power cable. The Transceiver
operates on 13.8 VDC, negative ground. Battery polarity must
be correct. The power cable is color coded:
Red + (Positive polarity)
Red - (Negative polarity)
4. The transceiver has voltage protection which keeps the voltage
under 18VDC.
5. Once the voltage is over 18VDC, the transceiver will shut
down automatically. To restart the system, adjust the voltage
to 13.8VDC and switch off the power then switch on again.
4-2-3 Antenna
The type of antenna that is use will greatly affect the performance of
the transceiver. Use a properly adjusted antenna, of good quality, to
enable your transceiver to perform at its best. The antenna input
impedance is 50 ohms. Use 50-ohm coxial cable such as RG-8U or
8D-2V for this connection. If the antenna is far from the transceiver
the use of low coaxial cable, such as RG-8U is recommended.
Match the impedance of the coaxial cable and that of the antenna so
that the SWR is less than 1.5 to 10. The protection circuit in the
transceiver will activate if the SWR is particularity poor (greater than
3 to 1).
High SWR values will cause the transceiver output to drop, and may
lead to TVI or BCI reports.
CAUTION:
We recommend that you install a high quality lightening arrestor
in your antenna lines for protection again fire, electric shock,
personal injury, or damage to the radio itself.
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