USER’S MANUAL
SERIES 48750 RF REPEATER
N um ber of
Signals
dBm
m W
1
30.0
1000
2
26.0
398
4
22.0
160
8
18.0
63
16
14.0
25
32
10.0
10
64
6.5
5
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.
.
AGC AUTOMATIC SHUTDOWN
When the automatic gain control circuit reaches its limit (20 dB), the power amplifier stage is shut down
to prevent harmful distortion and potential damage to the repeater. Shutdown will only occur if the AGC
control limit is exceeeded for about a half second. Power is then cut for 2 seconds. After this time-out,
power is brought back on-line. If the overload condition is still present, shutdown will again occur in
about 1 second. This cycle will be repeated until the condition causing AGC to reach its limit is removed.
Conditions which can cause AGC to reach its limit include the presence of one or more very strong
channels, a strong in-band noise source, or amplifier oscillation due to inadaquate antenna isolation.
MANUAL GAIN ADJUSTMENT
The independent manual attenuators, RX for uplink and TX for downlink, are accessable from the bottom
of the unit. They are set fully counter clock wise, at min attenuation – max gain. Manual attenuation is
separate from the AGC so these attenuators can be used to reduce overdrive while maintaining the AGC
range. At fully clockwise, 20 dB of attenuation will be introduced in the respective gain path.
AC / DC POWER
AC power is supplied through a standard 3-wire male plug connected through a standard IEC-320 plug.
Connect this plug to any standard 3-wire 120 VAC outlet. A 5 x 20 mm, 3.15 amp fast blow fuse is used
to cut power in the event of a severe AC fault. A 5 amp mini ATO fuse is used between the 28 VDC from
the power supply and the control board which distributes the power to all components. This is located on
the control board.
WARNING:
ALWAYS REMOVE POWER BEFORE CHECKING OR CHANGING FUSES.
120
VAC can be lethal.
Always unplug
the amplifier before servicing the interior.
Never insert
conductive
objects into any opening.
Do not remove or probe
under the plastic safety cover over the AC terminals
of the 28 VDC power supply.
Always use
a standard 3-wire electrical outlet with safety ground for AC
power.
INSTALLATION
6Dwg 602300003500/Rev.1
6
