Tektronix 1705A instruction manual Zeroing in on a Satellite

Introduction

Zeroing in on a Satellite

In almost all cases a set procedure for Locating, Identifying, Finding (transpond- ers), and Optimizing will be followed. The 1705A Spectrum Monitor is a tool that greatly simplifies the individual steps so the correct satellite transponder can be accessed in the minimum time.

Locating the Satellite In most cases the elevation (angle above the horizon) and the true azimuth (direction east or west to the satellite) of the antenna will be the same as it was for the previous access of the same satellite. This angle can be found in one of two ways, calculation or approximation from previous accesses; however, no matter how the satellite is located the signal path will need to be optimized. In most cases the approximate location of the satellite is known from previous transactions and only identification of transponders and signal strength remain to be dealt with.

Identifying the Satellite Each of the satellites has one or more singular characteristics. In many cases the singular characteristics can be easily identified on the spectrum monitor, which can save valuable setup time. These characteristics can take the form of telemetry beacons, transponder polarization schemes, or blocks of non-video signals that stand out. And in a few cases, the easiest method of identification may be the fact that the satellite is near another satellite that is readily identifi- able.

Telemetry Beacons. Satellites have special tracking or telemetry beacons that are easily recognizable on the spectrum monitor. Not only do these assist in identifying the satellite, but they provide an accurate way to set the frequency offset to correspond with actual satellite frequencies. Figure 1-6 shows a typical Ku-Band satellite telemetry beacon. Note that the 1705A readout frequency can be offset to read the down link frequency in GHz. Similar beacons can be found on some C-Band satellites also.

1705A Spectrum Monitor 1- 13