Thor Broadcast F-MININODE-2RT FTTH Optical CATV RF Mini-Node | Receiver with Return Path | Two-Fiber HFC Design

FTTH Receiver with Return Path

Fiber to the home designs need an endpoint that hands television to the subscriber's coax while carrying cable modem traffic back toward the headend. The Thor F-MININODE-2RT is an RF optical receiver and return path transmitter built for that role in FTTH and hybrid fiber-coax networks. This model uses two fibers, one for each direction, which keeps the forward and return budgets independent of each other.

Forward Reception and Link Figures

The receiver handles wavelengths from 1200 to 1620 nm with input power from -6 to +2 dBm, and return loss of at least 55 dB with UPC connectors or 60 dB with APC. Passband options are 54, 70 or 85 MHz up to 1002 MHz. At -1 dBm optical input the unit produces about 21 dBmV with 80 NTSC channels and 450 MHz digital loading, with CNR of 51 dBc or better, CSO at -65 dBc and CTB at -67 dBc.

Return Transmitter and Connections

The return path transmitter is centered at 1310 nm with output power of 0 dBm for FP, or +3 dBm for DFB and CWDM versions, on an SC/APC connector as standard. Return passband choices are 5 to 42, 5 to 55 or 5 to 65 MHz at an input level of 20 dBmV per channel, with input return loss of 16 dB or better and RF gain flatness within 1.5 dB. Forward output impedance is 75 ohm with 1 dB flatness.

Laser Choice and Test Points

Link performance depends on the laser fitted: an FP laser gives CNR of 48 dBc or better with CSO and DTO at -55 dBc, while DFB and CWDM lasers raise CNR to 51 dBc with CSO and DTO at -60 dBc. Choosing between them is a question of route length and split count rather than installation practice. Test points are provided at -20 dB on the forward output and -20 dB on the return input for commissioning measurements.

Single and Dual Fiber Versions

Thor lists F-MININODE-2RT as the receiver and return path transmitter over two fibers, and F-MININODE-1RT as the WDM version that does the same work over a single strand. FTTH drops, MDU and hotel CATV distribution, and HFC networks carrying digital television with cable modem return are the usual applications. Use SC/APC angle-polished connectors on the optical ports; flat PC terminations need a PC to SC/APC jumper.