Introduction - Tait T880 II Series Adjustment Manual

T881 General Information C1.3
M880-00
1.1

Introduction

The T881 is a synthesised, microprocessor controlled FM base station transmitter
1
designed for single or multichannel operation in the 800 to 960MHz frequency range
with a standard power output of 5W. The RF section of the transmitter comprises a fre-
quency synthesiser which provides 100mW of frequency modulated RF drive to a 5W
RF power module. A thermal shutdown feature is provided in the T881 in case operat-
ing temperatures exceed acceptable levels.
A wide selection of audio characteristics may be obtained from the audio processor.
Optional circuit blocks are an audio compressor and a pre-emphasis stage. They can be
bypassed or linked to one or both audio inputs, and then back into the remaining audio
circuitry in almost any combination. All audio processor options are link selectable.
The synthesiser frequency is programmed via the serial communications port. Eight
channel select lines are accessible via an optional D-range connector (D-range 2 -
T800-03-0000) at the rear of the set.
All components are mounted on a single PCB. This is secured to a die-cast chassis
which is divided into compartments to individually shield each section of circuitry.
Access to both sides of the main circuit board is obtained by removing each of the chas-
sis lids. There is provision within the chassis to mount small option PCBs.
The front panel controls include line sensitivity, microphone socket and carrier switch.
This switch turns on the carrier (unmodulated) as an aid to servicing.
The T881 is 60mm wide and occupies a single space in a Tait rack frame, which has the
ability to accommodate up to seven standard modules.
1. Although capable of operating over the 800-960MHz frequency range, the T881 has an
8MHz switching range (see Section 1.2.3 and Section 3.1).
Copyright TEL 10/07/00