Tait T830 Series, Руководство по обслуживанию

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Copyright TEL 31/01/96
1.1 Introduction
The T838 is an FM base station power amplifier designed for single or multichannel
operation within the frequency range 136 to 174MHz. The output power capability is 10
to 60W.
The PA comprises a broad band, three stage drive amplifier whose output is split to
drive two separate output stages. The outputs from these final stages are then recom-
bined and filtered before being fed to the output socket. This type of balanced output
stage offers two advantages over single ended types:
• improved intermodulation performance in the presence of high signal levels
from adjacent transmitters;
• enhanced reliability: if one of the two output stages fails, the transmitter can
still produce one quarter of its rated power.
VSWR and thermal protection is incorporated into the basic design, while monitoring
and alarm signals are available for both forward and reverse power. The output power
is adjustable from the front panel.
The circuitry is built on a single PCB which is mounted directly on a die-cast chassis/
heatsink.
The T838 has a width of 60mm, occupying a single module in a Tait rack shelf (T99-770)
which will accommodate up to seven standard modules to give an attractive and con-
venient installation.