Thor Broadcast F-RF-RP4RX 4-Channel CATV Return Path Optical Receiver | 5-200 MHz Upstream | Dual Power, LCD Display

Upstream Receiver for HFC Headends

In a hybrid fiber-coax network the return path matters as much as the downstream lineup, because cable modems and set-top boxes answer on the low frequencies. The Thor F-RF-RP4RX collects return path signals from four optical links at the headend and converts them back to RF for a CMTS or other upstream equipment. One rack unit therefore aggregates four nodes' worth of upstream traffic.

Band, Levels and Channel Isolation

The receiver covers 5 to 200 MHz with in-band flatness within 1 dB and an output level of 105 dBuV or more, into 75 ohm with return loss of 16 dB or better. Isolation between channels exceeds 65 dB, so four nodes can share the chassis without interacting. NPR dynamic range is 15 dB or more with a DFB laser at the far end, or 10 dB or more with an FP laser, both measured at NPR of 30 dB.

Optical Input, AGC and Test Points

Received optical power and the AGC range both span -10 to 0 dBm, across wavelengths from 1100 to 1600 nm, with optical return loss above 45 dB. Output level adjustment covers 10 dB with the optical AGC enabled or 30 dB with it switched off, giving headroom to align each port to the upstream equipment. An RF test port is provided at -20 dB within 1 dB, and RF connectors can be male or female F type.

Chassis, Power and Environment

The unit measures 483 by 365 by 44 mm, a 1RU chassis for a standard headend rack, and accepts AC 90 to 250 V at 50 Hz or -48 V DC, consuming about 20 W. Operating temperature runs from -20 to +45 degrees C with storage from -20 to +65 degrees C and humidity up to 95 percent without condensation. Dual power supplies and an LCD display for monitoring are part of the design.

Headend Applications and Pairing

Cable operator headends, hotel and campus HFC networks with interactive services, and FTTx systems aggregating return traffic from several nodes are the usual deployments. Pair the receiver with Thor mini-nodes or return path transmitters at the field end, matching laser type to the required NPR figure. Use SC/APC angle-polished connectors on the optical ports; flat PC terminations need a PC to SC/APC jumper.