Operation & Maintenance Manual

TELCOSAT RPT 700
Page | 12
Document use is restricted to that described on the cover
Each module has five switches. Each switch has numbers engraved below them. Above the switches the
word “Attenuate” is engraved into the module.
When the switches are in the up position, towards the word Attenuate, the signal levels are reduced.
(Attenuate means to reduce the signal level). To increase power you toggle the switch down.
The numbers below the switches are calibrated in dBm. For instance, the switch numbered 20 means that
if the switch is toggled up, Attenuate, then the signal is reduced by 20 dBm. If the same switch is toggled
down then the transmit power is increased by 20dBm. This same process applies all three modules.
3.8 RSSI METER AND SIGNAL LEVELS
Your Repeater is fitted with a Receive Signal Strength Indicator (RSSI). The RSSI indicator is located
just above the row of attenuator switches and is displayed as green LED’s.
(NOTE: THE RSSI INDICATOR DISPLAYS RECEIVE SIGNAL STRENGTH ONLY. THEY DO
NOT DISPLAY TRANSMIT POWER.)
The RSSI indicator has a dynamic range of -80 dBm to – 65dBm.
The green LED’s display will start to illuminate when a signal strength of -80dBm or greater is received.
When aligning your antenna to the cellular tower the RSSI meter must be monitored during setup. When
you rotate your antenna you will see the RSSI indicator increase and decrease as you pass the signal with
your antenna.
3.9 ALIGNING YOUR DONOR ANTENNA TO A CELLULAR TOWER
It is very important not to have too much signal from the cellular tower on the “Area Fill”
input signal. Full bars on the middle module green LED RSSI display indicates possible
signal excess.
Rotate your antenna until you pick up a cellular signal from a Cell tower. If the signal strength is greater
than -80dBm then the LED window on one or both of the Uplink modules side will start to illuminate.
Adjust the antenna until the received signal is peaked. Check to see that the green LED display is not
more than about 80% illuminated. If you have 100% solid green lights on the centre RSSI display
window then you must reduce the receive signal level.
You can reduce the received signal level two ways.
1) Replace your Donor antenna with a lesser gain antenna.
2) If your system design will permit, slightly rotate the antenna away from the maximum signal until the
RSSI window reads about 98% of maximum display level.