How to connect several TV sets to a single aerial / aerial array?
When building an aerial system from scratch the task is much easier. We predict in advance how many receivers we want to receive which signals. Then we select the individual components of the network so that it meets all our requirements. This is different for an existing installation. In such a case we are often faced with the following question:
How do I connect additional TV sets to the aerial / aerial array without loss of reception quality?
However, this seemingly simple activity requires proper knowledge, and the solution depends on several important factors.
The basis is the strength of the signal that comes from the aerial or aerial array. With the use of the appropriate measuring equipment ( DVB-T/T2 signal meters) one needs to check the power level of the received signal. We can also use the signal level indicators visible on the TV screen during tuning. However, we have to know on what channel (frequency) a given MUX is received in our location. Then, in the course of setting the manual tuning of the receiver, we specify the frequency we want to receive and look for such a position of the aerial where the received signal will be best. What remains to be done is to calculate whether, after splitting, it will be high enough to supply several additional receivers with the correct level.
If the signal strength is high enough,then we use passive splitters to divide it.
One should take into account that using these splitters introduces attenuations that lower the signal level. Therefore, we recommend using low-loss splitters, such as: RM2/3/4F or PCT-1000-xW. Additionally, it is worth remembering that the higher the attenuation, the more branches the distributor has. Standard splitters available on the market are characterized by minimal attenuation on each branch at the level of 4dB (two-fold splitter), 8db (three-fold) or 11dB (four-fold). For this reason one should not use splitters in which the number of outputs is greater than the number of televisions we want to connect. This is because it would cause an unnecessary reduction in signal strength. The number of TV sets to be connected to the network should be well thought out, so as to choose a device with the appropriate number of outputs. So if we want to connect one additional TV to the existing one, we have to split the signal from the aerial into two, using a two-output splitter. When we want to connect two additional TV sets, we divide the signal into three, so we use a three-output splitter, etc.
If, in turn, the signal strength is low,then, after splitting the signal, it may turn out that the quality of reception on any of the receivers does not meet our expectations. In such situations active splitters should be used, e.g RTA-120 or RTA-140. They are equipped with a built-in amplifier that compensates the losses resulting from splitting the signal and partially compensates for attenuation of the cable leading to the receiver. It is also the common cause of signal loss, so the use of good quality coaxial cables is as important as the selection of an appropriate aerial for the installation. For longer distances between the splitter and the receiver, exceeding 10–15 m, the loss may be so significant that it should be taken into account when choosing an appropriate splitter.
Sometimes, however, the signal coming from the aerial is so weak that even the use of active splitters may not be sufficient. In such a case it should be amplified in the previous section of the installation, using e.g. a single PAR-820 preamplifier before the splitter. However, remember to power it up! The downstream splitter should be able to pass the voltage. It will be similar if the existing installation is based on an aerial with a built-in preamplifier. Using a splitter that passes voltage to the aerial will then be necessary for proper operation of the installation.