DB
ELETTRONICA TELECOMUNICAZIONI S.p.A.
PM 1000 – 1 kW FM Broadcasting Transmitter - U
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ANUAL
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GENERAL BLOCK DIAGRAM DESCRIPTION
The general block diagram (see Fig.3.1) consists of the following blocks:
A)
PM1000 RF Amplifier Stage delivers the 1050W output power.
It is realised by means of the following modules:
1) AMP30 (DB 0110_010A) preamplifiers/driver stage for delivering about 24 W RF power.
2) Input splitter (DB 9DB 9702_007) that divide the 24 W in four equal parts to driving
the four AMP300 final amplifiers.
3) Four AMP300 300 W MOSFET technology amplifiers (DB 9812_001).
4) Output coupler (DB 99701_002A) for combining the four 300W stage outputs and to
obtain the full output power.
5) Output low-pass filter (DB 9901_001) and directional coupler (DB 9901_005) for
spurious and harmonic filtering and for forward and reflected output power monitoring.
B) Protection and control board (DB 9601-002) for monitoring and controlling all principal
transmitter parameters.
C) PM 1000 Power Supply Stage. For driving the RF section there is a mains switching board,
giving the correct power supply (45V) for each 300W RF amplifiers. An other switching module
(DB 0206_090) is dedicated for protection and control board, meter stage, Modulator board,
AMP30 Driver stage and all optional boards.
D) PM1000 Meter stage display on a 40 LED scale all major transmitter parameters.
E) SINTEL 96 modulation board allows a high quality direct carrier modulation accepting a
composite stereo (MPX) coming from Stereo encoder (/S option) or a mono input signal with up to
3 SCA subcarriers (for example RDS, ARI, ...).
F) Stereo encoder board (/S option) generates a composite MPX signal for the modulation board
from R and L audio channel.
G) Stereo audio processor (/P option) performs a high quality sound compression.
H) Remote control board (DB 9702-006).
