| 摘要 |
PURPOSE:To eliminate a ring tone loop produced by a hybrid at both ends of a 2-wire converting circuit by using a terminal telephone set extended with a subscriber line while keeping the four-wire system. CONSTITUTION:An amplifier circuit 9' for compensating line loss, a dial signal transmission circuit RG transmitting a dial signal to a 4-wire system line, a in- band signal generating circuit 7', a signal circuit 8' and a power supply AC/DC adaptor 11 receiving commercial power supply and supplying the power to the said circuits are incorporated in a case of a subscriber telephone set 15, in a device of the subscriber side. Thus, the transmission loss attended with the conversion of two/four-wire and the member for loss required for stabilizing ring tone are not required and the entire transmission loss is reduced. |
