The JFW Industries 75BR is a manually variable step attenuator engineered for 75-ohm RF applications requiring precise signal control in laboratory and field environments. Front-panel knobs deliver step-by-step attenuation adjustment with repeatable accuracy across DC to 2150 MHz, depending on model selection. Three connector options (BNC, F, or N female) accommodate diverse system integration requirements. Built for extended operational life, the 75BR withstands 500,000 attenuation cycles per knob and operates reliably from −20 °C to +85 °C.
## Technical Specifications
**Frequency & Power**
• DC to 1000 MHz (75BR-014)
• DC to 1218 MHz (75BR-036)
• DC to 2150 MHz (75BR-023)
• RF input: 1 W average (75BR-014, 75BR-023); 1000 W peak (75BR-023)
**Attenuation**
• Up to 90 dB (75BR-014)
• Up to 70 dB (75BR-023, 75BR-036)
• Step sizes: 0.25 dB (75BR-036), 1 dB (75BR-014, 75BR-023)
• Accuracy: ±0.15 dB at 0.25 dB steps (75BR-036); ±0.5 dB at 1 dB steps, ±0.7 dB or 3% at 10 dB steps (75BR-023)
**VSWR & Loss**
• VSWR: 1.5:1 max DC–500 MHz, 2.0:1 max 500 MHz–2150 MHz (75BR-023); 1.7:1 max (75BR-036)
• Insertion loss: 1.5 dB maximum (75BR-023)
**Physical**
• Benchtop enclosure, approximately 2.3 lbs (75BR-014, 75BR-023)
• Operating temperature: −20 °C to +85 °C
## Key Features
• Manual step adjustment via dual front-panel knobs (typically 1 dB and 10 dB controls)
• Rated for 500,000 attenuation steps per knob
• Counter-clockwise rotation increases attenuation (75BR-023)
• Indexed adjustment with stops at minimum and maximum positions (75BR-023)
• Selectable RF connector interfaces for system flexibility
## Typical Applications
• RF test and measurement setups
• Telecommunications system validation
• Signal level simulation and control
• Cable and component characterization
## Compatibility & Integration
Rear-panel RF connectors support BNC, F, or N female connector options. Manual control eliminates external power or control signal requirements, enabling deployment in standalone test configurations or as an inline component within signal chains requiring manual attenuation adjustment.
