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The Agilent 41800A is an active probe covering 5 Hz to 500 MHz, designed to provide reliable in-circuit signal analysis when paired with a network or spectrum analyzer. The probe combines high input impedance with low input capacitance to enable measurements with negligible loading of the circuit under test, making it suitable for precise probing at the circuit level across audio, video, HF, and VHF frequency bands.
The 41800A supports two primary application areas as described by the manufacturer. When used with a spectrum analyzer, it evaluates circuit quality through measurements of spurious level, harmonics, and noise. When used with a network analyzer, it enables gain, phase, and group-delay measurements at the circuit level. These pairings make the probe a tool for both signal-quality characterization and frequency-response analysis on assembled circuits and prototypes.
Hewlett-Packard's test and measurement business was spun out as Agilent Technologies in 1999, and Agilent's electronic measurement business was then transferred to Keysight Technologies in 2014. The 41800A active probe was originally released under the Agilent brand and remains supported through the Keysight successor organization for the categories where service continues.
| Specification | Value |
|---|---|
| Bandwidth | 5 Hz to 500 MHz |
| Probe gain | 0 dB ± 0.5 dB @ 50 MHz |
| Input R, C (typical) | 100 kΩ, 3 pF (probe alone); 1 MΩ, 1 pF (with 10:1, 100:1 divider) |
| Frequency response relative to 50 MHz | +1/-2 dB @ < 50 Hz; ±1 dB @ 50 Hz to 200 MHz; +1.5/-2 dB @ > 200 MHz |
| Average noise level (typical) | 10 nV/√Hz @ ≥ 300 kHz; +3 dB/Oct @ < 300 kHz |
| 2nd harmonic distortion (typical) | < -50 dBc @ -20 dBm (250 MHz) input |
| 3rd order intermodulation distortion (typical) | < -70 dBc @ -26 dBm two signals input (400 MHz, 400.5 MHz) |
| 1 dB gain compression | > +3 dBm input @ 500 MHz |
| Maximum allowable input (DC + AC) | ±40 V |
| Output connector | 50 Ω type-N male |
| Power | +15 V/85 mA, -12.6 V/65 mA |
| Weight | 0.3 kg (probe alone); 2 kg (including accessories) |
| Length | Approximately 1.2 m |
| Operating temperature / humidity | 0 °C to 55 °C, RH ≤ 95% (40 °C) |
Please review the Manufacturer's Data Sheet to verify published specifications. Feedback on this webpage is always welcome — please reach out to your Test Architect at any time for questions or concerns. Thank you, we truly appreciate you being our customer.
Model No
Agilent
Condition
Used
Manufacturer
Agilent
Frequency
500 MHz
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