Telebyte Model 279 Single Mode to Multi-Mode Convertor 220 Volts
The Model 279 provides transparent conversion between fiber optic devices utilizing multi-mode fiber and those with single-mode fiber. Single-mode fiber can transmit data over much longer distances than is possible with multi-mode fiber. It accomplishes this by limiting the amount of power lost through leakage in the walls of the fiber and using 1300 nm wavelength emission which has less attenuation than 850 nm. Thus, this converter regenerates signal strength and is used to extend the distance far beyond the specification for multi-mode fiber. The Model 279 can also be used when the optical fiber type of the equipment is not compatible with the installed fiber optic cable. Features of the Model 279 include the ability to operate from DC to 2.5 Mbps. This allows a variety of applications to take advantage of the transmission capability of the device and fiber cable. A loss budget of 15 dB is provided which equates to a distance of approximately 20 kilometers. Since operation is allowed at DC there is no clocking information that the Model 279 can use to perform automatic gain control. Therefore, the gain is user-controlled by a Line Loss switch and, once set, does not have to be changed. Once the single-mode line is installed its length is fixed. Four positions on the Line Loss switch allow selection of 2, 5, 10 and 15 dB of loss. Four LED’s are provided to give a visual indication of the selected line loss. The units are used in pairs, interconnected on the single-mode side. The Model 279 is powered by a wall-mounted DC adapter that develops 12 V. By use of an internal DC-to-DC converter the user can supply any DC voltage from +8 V to +36 V for those situations where AC is not available. The fiber optic ports of the Model 279 are provided on ST connectors. The product is designed for inline mounting. It’s relatively small size allows for placement in virtually any installation.