Note: Not compatible with pulse/rotary dialing.
The TBB-1B will boost talk battery voltage up to 48VDC, and current up to 26mA on single analog line extensions behind PABX’s and electronic key systems. This is helpful for powering line powered devices such as touch tone dialers and emergency phones on low voltage and/or low loop current extensions.
When the TBB-1B is being used, the power LED lights extra bright to show activity. The TBB-1B is not compatible with Pulse/Rotary dialing.