Varian VUU-8537 Ku Band WR-62 C Band WR-137 Waveguide Dummy Load Assembly

Varian VUU-8537 Ku Band WR-62 C Band WR-137 Waveguide Dummy Load Assembly

The Varian VUU-8537 is a multi-section microwave waveguide dummy load and directional coupler assembly designed to terminate and sample RF power in both Ku Band (WR-62) and C Band (WR-137) waveguide systems. The assembly integrates a power termination section — using a finned heatsink block to absorb microwave energy — with a three-port directional coupler bar that allows signal sampling at calibrated coupling levels across the frequency range. A flexible waveguide section (flex-guide) on the Ku Band WR-62 port accommodates mechanical alignment. This is a specialized piece of microwave plumbing used in antenna feed systems, satellite ground terminals, radar, and other high-frequency RF signal chains.

Specifications & What's Included

• Manufacturer: Varian MED, FSCM 59782, Made in USA
• Model: VUU-8537
• Sub-assembly part number: 01050282-00 A
• Ku Band port: WR-62 waveguide with flex-guide section
• C Band port: WR-137 waveguide (long straight run section)
• Directional coupler bar: 3 positions, numbered 1, 2, 3
• Coupler port connectors: N-type (female), one per coupler port
• Each coupler retains original calibration card showing Coupling (dB) vs. Frequency (GHz) data
• Coupler 1 calibration: approximately 50 dB coupling across calibrated frequency points
• Coupler 2 calibration: approximately 52 dB coupling across calibrated frequency points
• Coupler 3 calibration: approximately 60 dB coupling across calibrated frequency points
• Termination section: finned aluminum heatsink block for RF power absorption
• End connector: circular multi-pin military-style connector (visible in photos)
• Additional coaxial N-type fitting at the termination/base section
• Mounting bracket integrated into coupler bar

Applications

Waveguide dummy loads like the VUU-8537 are standard components in microwave and satellite communication ground systems, radar installations, and high-power RF test environments. In these systems, a dummy load provides a matched termination that absorbs RF energy without radiation, allowing transmitter and feed chain testing or protection when an antenna is not connected. The integrated directional couplers on this assembly allow engineers to sample the signal at each coupler port with a known, calibrated attenuation — a common requirement when monitoring transmit power or characterizing a feed chain. Varian was a prominent manufacturer of microwave tubes, components, and subsystems from the mid-20th century onward, and their waveguide hardware was widely used in defense, satellite earth stations, and scientific research installations. The dual-band WR-62/WR-137 configuration makes this assembly relevant to systems that operate across both Ku Band (approximately 12–18 GHz) and C Band (approximately 4–8 GHz), such as dual-band satellite uplink/downlink feeds or test benches covering both ranges.