Procom has unveiled two new TETRA combiners – a two-channel version and a four channel version. The four-channel TETRA station combiner (PRO-MIX-PHY-TETRA-4-N) consists of a highly selective helical duplex filter for each input. This duplex filter will split the transmitter (TX) signal and the receiver (RX) signal in two and send the TX-channel to an isolator and the RX-channel to the passive RX-splitter.
From the isolator the TX-signal is fed through a low-pass filter into a hybrid. From the hybrid the four TX signals are fed to another helical duplex filter similar to the input duplex filter and is now connected to the antenna. The RX-signal runs from the antenna through the output duplex filter to a hybrid splitter where it is divided into four and sent to the four input duplex filters.