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User Manual
Rev. 1.2 - 21/01/11
TEX2000LCD
8.8 BIAS Board (SLBIASTEX2K)
The main purpose of this board is to control and correct the bias voltage of
the RF amplification section MOSFETs.
It also provides a measure of the total current drawn by the RF modules and
incorporates a dedicated circuit for power supply fault reporting.
Under normal conditions, bias voltage is adjusted according to set output power
using feedback based on actual output power reading (AGC).
Abnormal conditions affecting bias voltage so as to trigger foldback current limiting
are:
•
Reflected output power too high
•
External AGC signals (Ext. AGC FWD, Ext. AGC RFL)
•
Temperature too high
•
Current draw of one RF module too high
8.9 External Telemetry Interface Board (SLTLMTXLCD03)
This board provides an I/O interface for the CPU with the outside environment. All
available equipment input and output signals are brought to the REMOTE DB15
connector (sect. 6.3.4).
Also mounted on this board is the INTERLOCK IN BNC connector (figure 6.2 - [25])
which can disable device power output. When the central pin is closed to ground,
output power is limited to zero until ground connection is removed.
