Black Box MT257A Marine RADAR User Manual


 
8
G.703 ADAPTERS AND BALUN MATE II
2. Introduction
The G.703 Adapters and the Balun Mate II enable
75-ohm coaxial G.703 equipment/networks to
communicate with 120-ohm twisted-pair G.703
equipment/networks. They’re specifically designed to
address the Open Network Provision (ONP)
requirement that European PTTs offer 120-ohm twisted-
pair terminations to their customers. Some PTTs and
private carriers had standardized on 75-ohm coax, or
have customers whose CPE has only 75-ohm
connections. The Adapters and the Balun Mate II help
solve this termination mismatch by converting 75-ohm
signals to 120-ohm signals and vice versa, at data rates up
to full E1 speed (2.048 Mbps).
The MT255A-M model of the G.703 Adapter has a
pair of 6" (15.2-cm) coaxial pigtails with male
connectors that can plug into the female coaxial
connectors of an existing device or termination.
The MT256A-F model of the G.703 Adapter has a pair
of female coaxial connectors that existing coaxial cables
can be plugged into.