JVC TDR6 installation and operation guide Input Status LED Not Illuminated, Minimum E b /N 0 dB

To clear the fault history log from a remote unit issue the FAULTLOGCLEAR command.

Initialization Self-TestThe TDR6 has several built-in-self-tests. many of these tests are performed Function automatically when the unit is powered up or reset. Faults detected when the unit

is powering up are displayed as error messages on the LCD screen.

Other self-tests are performed during real-time operation as the system monitors the transport stream. Faults detected while the unit is running are indicated by the LEDs on the front panel.

You can also query the system on the status of faults using the Faults menu.

Troubleshooting the This section provides information on troubleshooting the QPSK demodulator in a QPSK Demodulator TDR6 configured with a TDEM-6110 option module.

Input Status LED Not Illuminated

If the Status LED is not illuminated, the demodulator, decoder, or the transport stream is not locked. This problem may be caused by:

■Receive signal Eb/N0 level is to low

■Receive signal power level is to low

■Receive carrier offset is wrong

Receive Signal Eb/N0 Level

The Eb/N0 value in the Details menu under Input/Status displays the estimated Eb/N0 level of the receive signal in units of decibels (dB).

The minimum Eb/N0 level required by the QPSK demodulator for flawless video reception at each Viterbi Code Rate is listed in the following table.

Viterbi Code Rate And Eb/No Minimum Levels for QPSK

Demodulator

Viterbi Code Rate	Minimum Eb /N0 (dB)
1/2	4.5
2/3	5.0
3/4	5.5
5/6	6.0
7/8	6.4

An Eb/N0 level above the minimum DVB requirement is acceptable.

■If the Eb/N0 level drops below the minimum DVB requirement, the video reception can be interrupted or of poor quality.

■If the Eb/N0 level is above the minimum DVB requirement, the TDR6 should acquire the carrier, demodulate the signal, allow the decoder to lock the transport stream, and provide decoded video and audio output.

For information on estimating the Eb/N0 level, refer to the appendix on the QPSK demodulator.

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