CPI 6275 25W C-Band MBUC

CPI 6275 25W C-Band Marine SATCOM Block Upconverter (MBUC)

The CPI 6275 Series 25W C-Band Micro/Mini Block Upconverter (MBUC) is a maritime RF upconverter and power amplifier designed for high-availability commercial shipping, offshore energy vessels, and naval satellite communications. Designed by Communications & Power Industries (CPI), this compact, feed-mountable unit translates standard L-Band intermediate frequencies (IF: 950–1525 MHz / 950–1825 MHz depending on sub-band selection) directly to the operational C-Band uplink transmission window (5.850–6.425 GHz Standard C / up to 6.725 GHz Extended C) with a rated saturated linear output power of +44 dBm (25 Watts nominal).

The CPI 6275 features an environmentally sealed IP66/NEMA 4X aluminum chassis that tolerates continuous mechanical vibration, high-G wave impacts, and extreme maritime thermal fluctuations (-40°C to +55°C). The internal GaAs/GaN solid-state power amplifier (SSPA) chain delivers low phase noise (compliant with IESS-308/309 and MIL-STD-188-164) and high third-order intermodulation rejection (-25 dBc minimum at 3 dB output back-off), eliminating spectral regrowth and adjacent carrier interference in multi-carrier, high-throughput maritime satellite links.

Model Details

• Manufacturer: Communications & Power Industries (CPI)
• Model: 6275 Band IF MBUC
• Manufacturer Part Number (MPN): CPI 6275 (Sub-variants: 6275-25W-C-AC, 6275-25W-C-DC, 6275-C-F1F2-25)
• Equipment Type: Solid-State C-Band Block Upconverter / Feedhorn SSPA Unit
• Configuration: Waveguide-mounted / Pedestal-integrated transceiver assembly

Technical Specifications

Applications

• Commercial Deep-Sea Cargo & Tanker Fleets: Delivering constant high-bandwidth, weather-resilient corporate communications, electronic chart (ECDIS) updating, and crew internet over C-band beams.
• Offshore Oil & Gas Installations: Mounted on drillships, FPSOs, dynamic positioning (DP3) exploration rigs, and offshore service vessels requiring C-band satellite stability unaffected by tropical rain fade.
• Cruise & Passenger Lines: Serving as dedicated uplink transmitters for redundant maritime VSAT telecommunications arrays.
• Naval & Coast Guard Auxiliary Vessels: Defense-grade tactical satellite internet, real-time video downlink relay, and military telecommunications links resistant to phase jitter.
• Remote Coastal Base Transceivers & Island Teleports: Land-based coastal radar and shore-to-ship microwave relay transceivers requiring feed-mounted outdoor BUC hardware.

Frequently Asked Questions

Can the CPI 6275 be powered directly over the IF coaxial cable?

Yes. The unit supports multiplexed DC injection over the center conductor of the 50-ohm Type-N input port (J1), provided the external bias-T or satellite modem power supply delivers +36 VDC to +55 VDC at up to 5 Amperes. Alternatively, power can be supplied via a dedicated circular multi-pin Mil-spec connector depending on the terminal block configuration.

What is the distinction between Standard C-Band and Extended C-Band on this model?

Standard C-band operates across an uplink frequency of 5.850 GHz to 6.425 GHz utilizing a standard 4.900 GHz Local Oscillator (LO). Extended C-band variants cover 5.850 GHz up to 6.725 GHz (using alternate LO frequencies or wider dual-band filters). Check the serial label on your unit for exact frequency options before installing it in foreign satellite beams.

How do I configure the BUC attenuator if the modem output is too hot?

The CPI 6275 features an internal 30 dB programmable attenuator accessible through the serial M&C port (RS-485 / RS-232) using standard ASCII commands or an FSK link from compatible indoor units (IDUs). To avoid intermodulation distortion and harmonic generation, set the IF input level between -20 dBm and -10 dBm to prevent overdriving the input mixer.

Is an external waveguide isolator required with the CPI 6275?

No. The CPI 6275 has an integrated, full-power ferrite circulator/isolator load inside the output assembly. It can withstand an infinite load mismatch (including open or short circuits) without damaging the internal GaAs/GaN output stages.

How do I clear an “RF Mute” condition in the field?

An active RF mute condition occurs if the 10 MHz reference signal drops below -12 dBm, the LO synthesizer loses lock, the unit exceeds +75°C internal baseplate temperature, or pin J of the M&C connector is held low. Verify the reference carrier presence, check thermal heatsink clearance, and monitor the bi-color diagnostic LED on the connector bracket (Solid Green = Operational; Red = Hardware Alarm / Muted).