Operating Manual

PRELIMINARY FCC ID: BIB61201001 INTALLATION 3-2
PRELIMINARY MCC-6120 SDR Packet Data Radio Network
8-10 ms to several dozen every 8-10 ms. As the number of spikes increase, the level of
interference also increases. When setting up a site, always use the MM command to determine
the level of the power line noise interference. It is mandatory that power line noise be avoided
for an optimum site. Try to place the receiver antenna well away from power lines.
NOTE
Power companies are required to properly maintain their power lines to reduce noise. Call the
local utility in case of severe noise.
Computer-Generated Interference
All computers and printers contain high-speed circuits that generate spurious signals throughout
the 39-50, 151-160 MHz band. Interference will result if any of these signals couple into the
antenna at the MCC-6120 SDR receive frequency. To minimize this type of interference, try to
keep the antenna away from computers by at least 100 feet.
Signal Interference
This type of interference will occur whenever another transmitter is producing harmonics at the
receiver center frequency of the MCC-6120 SDR. Antenna nulling and spatial separation can be
used to reduce this type on interference.
NOTE
With XTERMW installed (see Section 3.3), the STAT command can be used to determine the
site antenna noise levels. Ideally, the background noise levels should be less than –107 dBm
(1µV into 50Ω).
3.1.2 DC Power Source
The MCC-6120 SDR requires a 12-15 V
DC
power source. The average standby current is about
600 mA. When the unit transmits (low band) it requires about 22 amps for 100 msec. For
normal operation, including the transmitter, the average current requirement will be
approximately 2.8A when operating at a normal duty cycle of 10%. An automobile battery
provides an excellent power source.
When the unit is operating as a base station there will normally be AC power available. A car
battery connected to a battery charger provides a good solution. In the event of a power outage
the battery will keep the MCC-6120 SDR on-line and operational for several days until the
power is restored.
CAUTION
The MCC-6120 SDR does not have an internal fuse and consideration should be given to
installing an external fuse.