Thor Broadcast F-RF-1550-Tx-EM-2 Externally Modulated 1550 nm CATV Transmitter | Analog, QAM & ATSC | Long-Distance RF

Externally Modulated Long-Haul Transmitter

Over long single-mode routes, laser chirp interacting with fiber dispersion distorts the signal before it arrives. The Thor F-RF-1550-Tx-EM-2 avoids that by modulating externally rather than driving the laser directly, carrying analog CATV and digital QAM or ATSC signals. It is built for larger networks where RF has to travel a long way before being amplified and distributed, rather than for a single building-to-building hop.

Laser, Outputs and Link Quality

A high-power, low-noise continuous-wave DFB laser with a typical line width of 0.65 MHz feeds four high-linearity optical outputs, each delivering 7.0 dBm or more and each able to drive a high-power FTTB EDFA. Without an EDFA, back-to-back CNR is 53.5 dB or better on a 60-channel PAL-D load, with CTB and CSO at -65 dB. Side mode suppression is 45 dB or better and equivalent noise intensity -160 dB/Hz or lower.

RF Band, Levels and Connectors

Working bandwidth is 47 to 862 MHz with a 47 to 1000 MHz option, at an AGC-managed input level of 18 to 28 dBmV on a 75 ohm F-female connector with return loss above 16 dB. Flatness is within 0.75 dB to 862 MHz and within 1.5 dB on the optional extension above it. Optical outputs use LC/APC connectors with return loss of 50 dB or better, and SBS suppression is adjustable from 13 to 19 dBm.

Wavelength Control and Management

Operating wavelength covers 1548 to 1563 nm, adjustable within 1.6 nm, equivalent to 200 GHz, in 0.05 nm steps, so a channel can be placed precisely on a DWDM grid. Wavelength stability is held between -1 and 0 pm per degree C across a 20 to 70 degree C case range. Management is available through an RJ45 SNMP network management interface and an RS232 communication port for local configuration and alarm reporting.

Versions and Typical Networks

Thor lists F-RF-1550-TX-EM-2 at +2 dBm and F-RF-1550-TX-EM-4 at +4 dBm output. Over 65 km of fiber at 0 dBm received, CNR remains 52.0 dB or better on a 60-channel load. City-scale CATV backbones, regional headend interconnects and large FTTH networks are the usual deployments. Configurations are quoted per project, since wavelength plan, output count and amplifier pairing all depend on the network design.