Operation Manual Part 1

ManualsBrandsThomson Broadcast & Multimedia ManualsElectronicsUHF Digital transmitter, for use with MediaFlo

Digital Liquid Cooled UHF

TV Equipment

Detailed operational description

9946 V1

45321648.01 104 A E

preliminary

26 / 131

Numéro / Number Doc. Rev. Lan

16/06/2006

Information contained is this document is confidential, is THOMSON property and cannot be disclosed in whatever form without prior written authorization of THOMSON.

Input liquid temperature fault

An "input liquid temperature" fault signal from the sensor in the internal cooling system sends a

command to lower the transmitter power by 6 dB.

SWR or amplifier overdrive fault

When the number of faulty amplifiers (SWR or overdrive fault) in the amplifier channel is greater than a

particular number (which depends on the total number of amplifiers), the fault processing system

triggers the following sequence of operations:

♦ re-initialisation of the faulty amplifiers,

♦ if the fault persists:

• reduction of transmitter power by 3 dB,

• re-initialisation of faulty amplifiers.

♦ if the fault persists:

• reduction of transmitter power by 6 dB,

• re-initialisation of faulty amplifiers,

♦ if the fault persists: shutdown of transmitter

SWR antenna fault

When the return wave antenna is higher or equal at 2, the fault processing system triggers the

following sequence of operations:

♦ reduction of transmitter power by 3dB.

♦ if the fault persists: reduction of transmitter power by 6 dB

♦ if the fault persists: shutdown of transmitter.

Automatic exciter changeover (only applies to the dual drive version)

The fault processing system sends a changeover to reserve exciter command signal to the command

control system when one of the following fault signals is received and when the reserve exciter is

switched off and fault-free:

♦ Exciter fault :

• Communication link failure with the Sirius,

• Power supply of exciter fault,

• RF output signal missing from Sirius (Sirius rack is ON with an modulator not mute).

• Modulator fault,

• Sirius fault,

• RF preamplifier fault,

• Signal missing of the 10 MHz external (external GPS configuration only),

• Board fault (synthetizer or TS board or Tx board or GPS board (internal GPS configuration only)

or EXT INPUT board (if installed card).

♦ Pilot fault :

• Signal missing of the 10 MHz external when the synthesizer 10 MHz is configured in external.

• 1 PPS signal missing when MUTE function is selected for this signal (in mode SFN only).

♦ Absence or input MPEG-2 signal faulty when the modulator is not configured in PRBS (this

configuration is not possible in SFN mode).