What does correct setting of a satellite dish or improvement of the signal depend on?
While following industry forums recently, we came across a discussion like this:
A forum member was having trouble with his signal and asked what kind of meter he should buy or borrow to be able to set up his satellite dish correctly. One of the "experts" advised him quote "Why do you need a meter when you have a dish?". Despite the validity of this very pertinent comment, we decided to expand on the topic a bit. I also hope that the author of this comment meant a satellite dish, and not some other instrument or device.
Signal parameter requirements
The change of the terrestrial television broadcasting system from analogue to digital and the transition to satellite broadcasting in DVB-S2 standard and MPEG-4 compression have significantly raised the bar for the requirements for signal parameters. In return, we were given the opportunity to place more channels and/or improve the quality of those currently broadcast. There was also a significant increase in data rate by about 19Mbps on average. This is a lot.
Weather conditions and reception problems
Currently all Polish HD channels are broadcast in DVB-S2 standard, but nothing is "for free". In poorer weather conditions, rain or heavy cloud cover they are the ones more prone to reception problems. This is because the higher standard requires much better signal ratios. Especially when it comes to the MER parameter (the minimum level is 14 dB for DVB-S2 in currently valid PN-EN-60728-1_2015E standard).
If the antenna installation is done properly, with good quality equipment and components, the antenna is correctly positioned and not too small, then generally the problems should not occur. During exceptionally intense weather events, it may of course happen that the signal will fade from one or two frequencies. The reason is that on the same satellite there are sometimes stronger and weaker transponders, but this is beyond our control.
Converter
Instead, we have an influence on the choice of an important element, which is the converter. Unbranded converters, due to their parameters and manufacturing technology, significantly increase the differences in signal reception. On a professional meter with SPEKTRUM function, e.g. TAB 4 Easy (see here), we can easily observe such an case. So the use of a brand-name LNB, e.g. FTE, is a very important element of every satellite installation.
Receiving antennas
As with any signal reception, the basic element in the installation is the receiving antenna. Thanks to the larger diameter of the antenna, we can get a larger ratio of correct signal to noise. This results in a more stable signal in poor weather conditions. Of course, there is no point in overdoing it and installing big "dishes". It is assumed that for proper reception of DVB-S2 (HD/SD) channels in Poland an antenna of 80-90 cm diameter is sufficient. With smaller diameters we have to reckon with possible gradual loss of reception stability. Such an installation will be more susceptible to changing weather conditions.
Antenna alignment
The second very important element is proper antenna alignment, and this requires accuracy. In the case of setting up a terrestrial antenna we could follow the "per neighbour" method. In this case, it is no longer that simple. We have to remember that the distance to a geostationary satellite, as opposed to a terrestrial TV transmitter, is over 35 thousand km. So moving the antenna even by 0.5 degrees makes a very big difference.
Surely, anyone can mount and set up a satellite dish, but only people with knowledge, skills and proper equipment can position it properly. Precise positioning of a satellite dish is very difficult. Writing about equipment and instruments I mean solid devices that measure important signal parameters, such as signal strength in dB, quality parameters MRE, BER, and not needle or LED indicators working on the "there is - there isn't" principle, which do not identify the satellite. This also applies to the percentage bars on the tuners. In capricious weather, every decibel of signal is important, and in many cases it's a fight for tenths of it.
Precision in antenna installation
The next problem with antenna installation is precision. When installing and positioning a satellite dish, details are important. The most common mistake is lack of adjustment of the converter's rotation angle - in LNB bracket the converter can be rotated freely. Proper installation means not only position of the converter with its "F" socket facing down, so that water cannot get inside the connector. When installing a converter, it is best to start with its position farthest away from the dish, as this position can be later adjusted during signal alignment. By moving the converter in a bracket in directions towards or away from the antenna mirror, we can use trial and error method to optimally align it in the focus of the dish's reflector.
Installer and measuring equipment
Despite precision in positioning the antenna, inaccurate placement of the converter is a big loss of signal. You can't do much here without a more accurate measuring device. Not every decoder will show this difference in the signal bars. It may seem that the antenna is positioned perfectly. And in the meantime, there is margin to do it better and gain a reserve for worse weather conditions. So it's worth considering the help of a professional installer.With the knowledge and equipment they have, they will be able to do this as accurately as possible.Only with a precision signal level meter can this be done really accurately.
Stable mounting
However, no equipment of even the best quality and precision in positioning the dish and LNB will help. Especially if we do not take care of proper selection and crimping of "F" connectors for coaxial cable, as well as we do not take care of sufficiently stable installation. Satellite dish is especially exposed to gusts of wind, putting much more resistance than traditional DVB-T antennas. The larger the diameter, the greater the forces acting on the supports and mounts, and thus on the converter holder. This translates into vibration of the entire system with the danger of a staged, slow dish movement and gradual unscrewing of the "F" connectors. This causes moisture migration and ultimately corrosion and short circuits. The consequence of this is a successive, significant loss on signal level, fluctuations, lack of stability of operation. This translates into increasingly poor quality and comfort of transmission.
So: good and tight connectors, decent, gelled coaxial cable, properly adjusted mounting structure for the size of the antenna and the type of the foundation, and solid workmanship of the whole installation. This is the best guarantee of correct and continuous operation of the system.
The only thing left is to fix the converter properly, precisely position the dish to the desired satellite.... and you are done. But that's a detail ..... 'cause after all, we have a "dish".