TANDBERG High Definition Professional Recevier/Decoder TT1280 - Manual (Page 70)

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Page 6-4 Reference Guide: TT128x High Definition Professional Receiver/Decoder
ST.RE.E10141.5
CAUTION…
1. The Receiver provides dc power (refer to Chapter 3, Operating the Equipment Locally) via the active
L-band input connector to drive an LNB (Low Noise Block Down-Converter). Do not connect
equipment other than an LNB to this connector. Failure to do this may result in damage to the
external equipment
2. The F-type connector is not suitable for repeated connection and disconnection. When intended for
use in this way, fit a sacrificial connector and connect to it.
6.3 HOM Input Card (TT1280/HWO/HOM)
6.3.1 General
The Higher Order Modulation Input Card supports QPSK, 8PSK & 16QAM
demodulation for Satellite Receivers with four L-band inputs.
6.3.2 Connector Details - L-Band Inputs
Connect the L-band output of a suitable LNB to the
F-type connector either directly or via a suitable
attenuator giving adequate consideration to lightning
and surge protection. The active input is chosen using
the Input Status Menu (Menu 2).
In most cases an attenuator will not be required. The following list
summarises the circumstances when one should be used.
When the desired input level is greater than the specified maximum
permissible (-25 dBm).
When the downlead is a short length of low-loss cable and the LNB in use
has a poor return loss (7 dB min).
When the Receiver is receiving one of many carriers in a multi-carrier FDM
system and the level of the wanted signal is close to the specified
maximum permissible.
The specification for this connector is given in Annex B, Technical
Specification.
Table 6.2: HOM Satellite Receiver (L-band) Connector
Input Specification
Connector Type F-type, Female
Connector designation IN 1, IN 2, IN 3, IN 4
Pin: Centre
Shield RF Input
Ground/Chassis
LNB Supply Refer to the next caution box
Impedance 75 Ω
IN 1/2/3/4