Subscriber station network

An improved telephone subscriber station network,

• said network comprising telephone lines for connecting subscriber stations to other subscriber stations,
• said telephone lines comprising at least two lines having a D.C. potential therebetween,
• receiver means for receiving communication signals from said lines,
• transmitter means for transmitting communication signals over said lines;
• first solid state electronic means coupling said transmitter means to said telephone lines for automatically compensating for losses on said telephone lines,
• said first solid state electronic means comprising a transmitter transistor for amplifying the communication signals generated at said transmitter means,
• said transmitter means coupled in series with the emitter and collector of said transmitter transistor,
• voltage divider network means coupled between said at least two lines,
• said voltage divider network means comprising a first resistor in series with a line compensating network,
• the base of said transmitter transistor being connected to the junction of said first resistor means and said line impedance compensating network, and
• means connected in the circuit including the transmitter and the transmitter transistor for controlling the transmission gain of said transmitter.

An improved subscriber station network for telephone systems including telephone lines for connecting said subscriber station to other telephone subscriber stations,

• said telephone lines comprising at least two lines having a D.C. potential therebetween,
• telephone receiver means for receiving communication signals from said lines,
• telephone transmitter means for transmitting communication signals over said lines,
• the improvement characterized in this that a first solid state electronic means couple both said transmitter means and said receiver means to said telephone lines for controlling transmitted and received signals for keeping the amplitude of the signals constant independent of line length,
• second solid state electronic means in series between said first solid state electronic means and said receiver means,
• means for controlling the gain of said second solid state electronic means responsive to signals on said telephone lines, and
• said first and second solid state electronic means being coupled together to control the amplification of said received signal and the sidetone from said transmitted signal.