TXRX Combiner

The Head-end equipments may consist of more than one single modem or voice repeater. A TXRX combiner is used to combine all voice and data signals into a single SIAMnet network.

The TXRX combiner is designed to operate in the 600 to 900 Mhz frequency band.  It may be equipped with up to eight (8) Modems (data) ports and four Repeater (voice) ports.

The “Tx Voice” and “Rx Voice” ports provide a 50 ohm connection to voice radio systems such as repeaters. The “TX Voice” port provides specific filtering, protection and manual input attenuation control.

The system In/Out port is a 75 ohm port that is connected directly to a bi-directional amplifier at the Head-end of the SIAMnet.

The “Tx Data” and “Rx Data” ports are general-purpose 50 ohm ports that can be used with any data radiomodem.

The TXRX combiner and other Head-end equipment are mounted into a 19-inch rack cabinet. The cabinet size is chosen to accommodate all the equipment required for the customer's application.

The Head-end cabinet includes the TXRX, voice Repeaters, base radio modems (BMRM), video demodulators, telephone interconnection units, power supply units, etc.

This cabinet protects the equipment from dust and other debris that could damage the electronic circuits and shorten the life span of the equipment.