User's Manual

File Doc. No. Date Version Page
DBHB-20 5700 9004 055 Nov. 05 1.0 11/13
Next Generation
Signal Enhancement
Annexure 2
Trouble shooting procedure DBHB-20
Conditions Possible Reasons & Solutions
A. Initially all the LED’s
will blink two times
1 Check the power cord and the AC power socket
2 Please note that the AC main power has to be within the
range 90~270VAC
3 Verify the D.C Adapter output voltage is 9V.
B. Signals are not
amplified after
completing the
installation
1. Check all the connectors of the repeater system for proper
connections. The “BTS” connector has to be connected to
donor antenna, and the “MS” connector has to be
connected to server antenna.
2. The poor isolation between donor and server antenna will
cause system oscillation and it may damage the amplifier of
the repeater. It is to note that the repeater gain should
be at least 10 db lower than the antenna isolation.
C. The system performed
well in the beginning
but after few days the
performance has
degraded.
1. The received signal level from the base station might have
degraded due to environmental changes such as new
building construction and so on. If so, please follow the
suggestions below:
a. Try to re-align the donor antenna towards the base
station
b. Adjust the gain attenuation of the Up or Down link
direction
c. Relocate the donor antenna to solve the problem
2. RF Cable problem: Check the RF cable for physical
damage by rats etc. Also check for sharp bands or RF cable
pressed. Under these conditions, RF signal losses could
have increased. If so, replace RF cable.
3. Indoor structural change: The signal level will vary
according to the interiors. Look for any interior changes
subsequent to the repeater installation or site survey. If so,
adjust the gain of repeater or re-align the server antenna
without affecting the existing coverage.
D. Alarm indication LED
will glow in red colour.
It indicates that the received signal level from BTS is high or
forward / reverse gain of repeater is high. If alarm persists for a
long time contact SHYAM technical support team.