ITEM # 602100023500
DOCUMENT TYPE:
Operation and Installation Manual
REV:
A
DOC #:
602100023
PAGE 13 OF 16
TITLE:
Bi-Directional Amplifier System
Oscillation may also take place between the 800 SMR band and a system for amplifying the 800
Cellular band. Contact RFS applications engineering for assistance.
Diagnostics/Troubleshooting
Test Point Descriptions
•
Green power LED indicates DC voltage is applied to the respective link.
•
Yellow AGC LEDs indicate AGC is active in the respective link
•
Red Fault LED indicates that a under or over current condition exists or that the AGC Shut Down
circuitry has been activated.
•
Relay NC (normally closed), C (common), NO (normally open) is a summary fault relay that
changes state whenever the fault LED is lit or when the power fails. This relay is rated for up to 48
VDC at 2 Amps.
•
Shut Down pin will cause the 48960 to shut down when it is connected to GND (ground). Current
draw is insignificant.
Problem:
Solution:
Green power LEDs on faceplate not
lit.
Check power source and the AC fuse located in the EIC plug.
Check the DC fuse located inside the 48960 on the side of the
individual amplifier modules. Check connections to the
internal power supply.
Red LED on faceplate is lit.
First, try to cycle the power then watch the AGC LEDS to
make sure the unit is not in AGC shut down. If the Fault LED
is cycling then an overdrive condition exists. See AGC
Automatic Shutdown section.
Green power LED lit and no red Fault
LED on faceplate; unit does not
appear to be working.
Check for a break in the donor or distribution networks. Also,
check to ensure the donor signal is still available to the
repeater. An obstruction could be blocking the donor base site
or the donor antenna could have become misaligned. Then,
check the integrity of the distribution network. Coaxial cable
has a minimum bending radius, if that is exceeded the inner
conductor may crack or break causing excessive reflections to
the signals.
Yellow AGC LED is lit.
AGC LEDs indicate an overdrive condition in the respective
link. Reduce the respective link gain via the Gain Adjust until
the LED goes out. Generally, the opposing link gain should be
adjusted to approximately the same setting. If the LED does
not go out, then the input signal is too strong. Sweep the input
to the respective link to identify the source of overdrive. If the
signal is not a desired signal then external filtering should be
considered to attenuate. If the signal(s) are all desired then
attenuate the base port with a 10 dB in-line attenuation pad.
IMPORTANT
The 48960 BDAs are not designed for field repair. The outer cover may be removed for
some troubleshooting but under no circumstances should the covers be removed from
the internal amplifier modules as this will void the warranty.
