Weinschel 1870 B RF Bolometer 12 dB 4.5mA Bias -55 dBm Power Detector Sensor

Weinschel 1870 B RF Bolometer 12 dB 4.5mA Bias -55 dBm Power Detector Sensor

The Weinschel Engineering 1870 B is an RF bolometer mount used for microwave power measurement. It incorporates a thermistor sensing element that changes resistance in response to absorbed RF energy, allowing a bolometer bridge instrument to measure incident power with high sensitivity. The unit features a 12 dB built-in attenuator, a 4.5 mA DC bias current, and a specified tangential sensitivity of -55 dBm, making it suitable for low-level RF signal detection. Manufactured by Weinschel Engineering of Gaithersburg, Maryland, a well-regarded name in precision microwave components and attenuators.

Specifications & What's Included

• Manufacturer: Weinschel Engineering, Gaithersburg, Maryland
• Model: 1870 B
• Type: RF Bolometer Mount / Power Detector
• Built-in Attenuation: 12 dB (as marked on face label)
• Bias Current: 4.5 mA
• Tangential Sensitivity: -55 dBm
• Detector Element: Thermistor bolometer element (visible on rear of disc)
• Body: Circular disc-shaped bolometer head with stainless steel handle/stem
• Connector: Coaxial connector on face (type consistent with N or similar microwave connector)
• Includes: Bolometer unit only — no cables, bridge instrument, or accessories

Applications

Bolometer mounts like the Weinschel 1870 B are used in conjunction with a bolometer bridge or power meter to measure low-level RF and microwave power. The thermistor element absorbs incident RF energy and changes resistance; the bridge circuit detects this change and converts it to a calibrated power reading. This type of detector was widely used from the 1950s through the 1980s in microwave laboratory and production test setups — common on HP (Hewlett-Packard) 430 and 431 series bolometer power meters, as well as similar bridge instruments from other manufacturers. Bolometer mounts remain sought after today for vintage microwave test bench setups, calibration labs maintaining legacy HP/Agilent power measurement gear, and educational/research applications where their sensitivity at low power levels is an advantage. The integrated 12 dB attenuator element extends the usable power range and protects the sensing element from overload.