# 85685A Agilent Analyzer Used

**Additional Features:**

-   Operates with the Agilent 8566B and 8568B spectrum analyzers
-   Reduces overloading from out-of-band signal
-   Improved system sensitivity
-   Built-in transient limiter
-   Frequency range RFP bypass: Input #1: 20 Hz–50 MHz; Input#2: 20 MHz–2 GHz; DC–18 GHz (nom.)
-   Connector type:  Input #1: BNC, 50 ? (nominal); Input #2: Type N, 50 (nom.)
-   Maximum safe input power: +30 dBm (1 Watt)
-   Attenuator range: 0 – 50 dB in 10 dB steps (nominal)
-   Linearity check: Add 3 dB (nominal)
-   Preamplifier gain: 20 dB (nominal) for 0 dB RFP attenuation

The 85685A preselector adds:

-   Automatic filter tracking
-   Input overload protection
-   Low system noise to the 8566B and 8568B spectrum analyzers

Add the 85685A RF preselector to the 8566B or 8568B general-purpose spectrum analyzer, and you have a test receiver for specialized applications. The RF preselector enhances these high-performance spectrum analyzers with tracking filters and preamplifiers that cover the 20 Hz to 2 GHz range. The spectrum analyzer/test receiver is sensitive to low-level signals while providing overload protection from out-of-band signals.

The result, for tests in the presence of high-level interference, is a measurement range 30 dB greater than that of the spectrum analyzer alone. (The improvement is even greater in the presence of broadband pulse-interference.)

The test receiver is easy to operate; simply use the spectrum analyzer controls without concern for preselector settings. The preselector automatically adjusts binput-filter tracking, and the spectrum analyzer reports preselector operating conditions on the CRT display. For remote operation with a computer, the receiver system is fully GPIB programmable (GPIB is hardware, software, documentation, and support for IEEE-488 and IEC-625, worldwide standards for interfacing instruments.)

## Details

- **Price:** 0.0 USD - 1875.0 USD
- **Vendor:** Agilent
- **Type:** Ana Oth
- **Tags:** Agilent, Agilent Keysight, Analyzers, Manufacturers, Other, product_manual_group_1, Product_used

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| None | 0.00 USD | In stock |
| Z540 With Data | 1875.00 USD | In stock |

## Images

- 85685A Agilent Analyzer Used

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> Source: [ValueTronics](https://valuetronics.com/products/85685a-agilent-analyzer-used)
> Updated: 2026-05-21