Articles

The article examines the main causes of cross-polarization interference, its detection using the IQmonitor family of programs, and its elimination during installation and configuration of a satellite antenna and LNB.

The IQmonitor program allows you to customize your receiving installation in the best possible way. To do this, there are tools for accurately measuring the signal level and SNR, the dynamic spectrum of transponders of both polarizations at once in real time, measuring the nonlinearity of the amplitude-frequency characteristic (AFC) of the installation and correcting its unevenness in RF spectra.
And for installation with an antenna on a polar motor suspension, it is possible to take the antenna pattern and determine the actual width of the main lobe of the pattern and the actual gain at different frequencies.
Unfortunately, the motor suspension consumes (especially in the cold season during start-up) a large (up to 0.5 - 0.7A) current, and you have to install it immediately after the drop cable to the receiver (PCI card input). In this case, the motor is connected in series with the LNB both by direct current and by a microwave signal. This leads to the formation of standing waves in the cable and a strong distortion of the overall frequency response of the receiving installation and, as a result, a decrease in its sensitivity.

IQmonitor Pro software is the best of its class for DX-eras and Feed Hanters for searching and deep analysis of DVB-S2 signals. It implements a number of exclusive algorithms and procedures that are based on tunnel computing technology with an efficiency of more than 800%, which made it possible to expand the range of capabilities of both budget and professional PCI and USB cards both in frequency (up to 3 times) and in resolution. and the accuracy of the spectra of DVB-S2 signals (up to 4 kHz). The interface of the IQmonitor Pro program is described below, which is not only a universal tool, but also a personal certificate of the highest user skill. The program is freely distributed on the site https://www.satellitescommunity.de/

In order to tune the receiving system to the global maximum sensitivity, you first need to match the angle of exposure of the antenna with its angular opening (sometimes they say "angular aperture", although this is not correct, IMHO), and then precisely align the antenna to the satellite.

If the LNB is not in the geometric focus of the parabolic antenna, then we will adjust the antenna not by the true azimuth and elevation of the satellite, but by choosing the "best" position of the LNB around…

IQmonitor Pro often scares off potential users with an abundance of interface elements that allow you to set dozens of parameters for optimal program operation.

What does optimal mean? - these are parameters that, depending on the task at hand, will provide either the maximum accuracy of determining the parameters of transponders at an acceptable speed of their search, or the maximum speed of constructing spectra of satellite signals with the condition of finding all above-threshold…