Teleline – T1

4-wire T1 Plug-in Isolator Card

4-wire T1 Isolator Plug-in Cards provide high voltage isolation between an incoming 4-wire T1 circuit and a Network Interface Unit (NIU) located in the substation.

  • 751329R2¬†features Surface Mount Technology (SMT) for increased reliability
  • 751329SP¬†features Surface Mount Technology (SMT) for increased reliability and offers a span powering option using -48 Vdc at 60 mA


  • T1 Carrier (1.544 Mb/s)
  • E1 Carrier (2.048 Mb/s)


  • Cards are suitable for transmission at frequencies up to 5 MHz provided the line is conditioned appropriately. Isolation of 50 kVrms (70 kV peak) its provided while maintaining full communication between terminals
  • Communication maintained across the gap by high voltage isolation transformers that provide low-loss low-distortion transmission.
  • The 4-Wire T1 Isolator plug-in cards can be installed while power is supplied to a Teleline Isolator shelf.
  • Simplex Sealing Current is provided for on the CO side. Sealing Current is not transferred to the Station side

The card can be housed any 4-wire capable 3-card shelf, 5-card shelf, or 8-card shelf, or in any of Positron’s pre-configured High Voltage Interface (HVI) units.

751329R2NPP13S0BAA4-wire T1 Plug-in Isolator CardUser guide
751329SPNPP14S0BAA4-wire T1 Plug-in Isolator CardUser guide