| 摘要 |
PROBLEM TO BE SOLVED: To provide a repeater to automatically compensate difference of optical loss due to difference of length of an optical cable connected between a master machine 3 opposed to a radio base station of the repeater mounted in an underground shopping area and a tunnel as a measure against a dead band and a slave machine 4 dispersedly arranged in the underground shopping area, etc., and opposed to a portable machine. SOLUTION: Current detectors 35, 44 to detect current values of O/E converters 34, 42 to convert received light into an electric signal are provided to both of the master machine 3 and the slave machine 4. The repeater is constituted so that the difference of the loss in the optical cable is compensated by providing gain control signals by which an output RF signal level transmitted to the portable machine corresponding to the detected current values becomes a stipulated value from control circuits 37, 45 to variable gain amplifiers 36, 46 respectively. A setting adjustment work in the case of new installation of the repeater and expansion of the slave machine becomes extremely easy.
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