52
When there is some interference, the C/N ratio is reduced, which renders the antenna
incapable of tracking towards the interfering source, while the AGC level increases, which
makes the antenna track towards the interference source.
Recommended
Preference
Tracking Reference
High
DVB AGC LEVEL:
The most recommended tracking reference is
DVB AGC if a DVB carrier is available. DVB AGC tracking can keep
the antenna point correct because fluctuation is lower than with DVB
C/N.
Medium
RSSD LEVEL:
When there is no reliable DVB carrier available on
the satellite, RSSD is the next preferred reference. It has a very
narrow BW so that the frequency can be tuned into a “sweet spot”
when there is interference. However, LNB must have very good
stability.
Low
DVB C/N RATIO:
This option is recommended when there is
severe interference from an adjacent satellite (ASI) or a local
radar/microwave, etc.
Table 6-2 Preference of tracking reference
6.2
Example of Using the DVB carrier
The DVB carrier is the most recommended method of searching and tracking if the
desired DVB carrier is available. The polarity, beam type, and LNB operating frequency
range of the DVB carrier must be the same as those which the on-board satellite’s modem
is using. Most public DVB carriers can be found in
www.Lyngsat.com
.
The benefit of using a DVB carrier is that it fully utilizes a state-of-the-art SAMYUNG
ENC built-in DVB tuner, so the probability of tracking the wrong satellite is very low. Also,
typically, the uptime of a DVB carrier is very high. When maintenance is being carried out
on the carrier which the satellite’s modem is using, antenna tracking is not interrupted.
NOTE:
If possible, it is recommended to pre-configure the necessary parameters to use
an external lock even though the DVB lock has already been selected as the searching
Summary of Contents for Ku-BAND RX
Page 1: ...INSTALLATION AND OPERATION MANUAL FOR VSAT VS61 Ku BAND TX RX ANTENNAS...
Page 15: ...7 Figure 3 1 Best Location Figure 3 2 Antenna Blockages...
Page 46: ...38 Figure 4 1 Step 1 of Reference Searching Definition...
Page 65: ...57 Figure 6 3 Co pol Kits Optional...
Page 120: ...d Appendix C Layout of Radome and Antenna Mounting Holes Figure C 1 Plastic Radome...
Page 121: ...e Figure C 2 FRP Radome Option...
Page 122: ...f...
Page 123: ...g Maritime Satellite Antenna...