Coax EPL Connectivity

Trying to replace a copper T1 with a 10Mb Coax EPL. Technicians cannot get the connection clean enough to support NEC SV8100's at each end. The EPL was installed Mid November of 2014, and we still have not been able to use it.

Has anyone else had issues with Coax EPL and phone systems? Is there something that can be done to clean up the connection to make it servicable?