A lot depends on the distance of your receiver from the transmission equipment. If the distance is very long, you need an antenna that can detect and receive data signals that have been weakened over the distance.
Signal can get weakened and disrupted due to tall trees, buildings and other such obstructions that come in its path of propagation. If you live in an area where the data signal faces multiple obstructions on its path, call a digital antenna installer as they would be a big help in detecting useful signal properly.
One directional and multidirectional antenna
One directional antenna points towards one direction and receives signals only from that direction. Multidirectional antennas can be used to pick up signals from multiple directions. Most of the home TV digital antennas are one directional. They are pointed towards the broadcast source during antenna installation and then receive digital signal all through the year.
Receiving direction in case of multiple direction antennas can be changed according to the direction of broadcast. This is very useful especially in case you are on the go or travel a lot. These antennas are commonly found on holiday caravans.
Number of channels required
A number of various bands and frequencies of channels are being broadcasted under digital TV. If you require the entire spectrum of channels, hire professional antenna installer to help you out in fixing and buying the right antenna to receive all the channels.
Depending on your sole usage and aim you can accordingly pick up a receiver based on its output and performance. Most people use between 5 to 8 for home use and larger amplifications for outdoor purposes. If you are investing in a system for your office conference room then a higher amplification is probably a better deal for you.