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5.9.7 Modem Acquisition, Low Power Carrier
In this example, we have created our new profile as in 5.9.1, however in this case we are using a
modem signal for our Acquisition Source. In moving from the old satellite to the new one, we find
that the modem reports back lower power (SNR) from the specified carrier than before. This is
causing the system to sometimes miss the satellite, resulting in a failed acquisition. The
recommended solution is to lower the following parameter to compensate. Keep in mind that
multiple parameters may affect a specific acquisition issue; we might also adjust the modem lock
threshold to improve the result.
- Scan Az Velocity (under signal parameters, level 4)
Figure 5.9.7 – Modem Scan Az Velocity
The Scan Az Velocity controls how quickly the antenna moves in Azimuth while looking for the first
sign of a signal from the modem. Because of this, we want to reduce this value only to the degree
required to obtain a consistent result without increasing scan times more than necessary. In this
case, the best value will be found with some amount of trial and error.
