What is the battery type used across the different models?

The Rohde & Schwarz FSH3 uses an internal NiMH battery. In contrast, the Rohde & Schwarz FSH, FSH4, and FSH8 models utilize Li-ion battery technology, with the FSH8 supporting up to 4.5 hours of operating time.

How does internal memory capacity differ on the FSH18?

The Rohde & Schwarz FSH18 features dedicated setup and trace memory that can store up to 100 different configurations and trace results directly on the instrument.

What are the differences in frequency resolution and reference aging?

The Rohde & Schwarz FSH, FSH4, FSH8, and FSH18 all feature a frequency resolution of 1 Hz. Reference frequency aging is less than 1 ppm/year for the FSH4 and FSH8, and 2 ppm/year for the FSH18.

Rohde & Schwarz FSH Series Handheld Spectrum Analyzers

6 models with full specifications from Rohde & Schwarz.

This page covers the Rohde & Schwarz FSH series of handheld spectrum analyzers, a family of rugged field instruments designed for the installation, maintenance, and troubleshooting of RF and microwave systems. This reference is for field engineers and RF technicians deciding which model best fits their frequency, measurement, and portability requirements. The family spans a wide performance envelope, with model-dependent frequency ranges beginning at 9 kHz and extending up to 20 GHz.

While all units in this series share a robust design optimized for on-the-spot operations, they vary in frequency range, internal hardware capabilities, weight, and display specifications. The base Rohde & Schwarz FSH model offers configurations up to 20 GHz, while more specialized models like the Rohde & Schwarz FSH3, FSH4, FSH6, FSH8, and FSH18 target specific bandwidth sectors, from lower-frequency mobile communications up to high-frequency microwave links.

Frequency Range: 9 kHz to 20 GHz (model dependent)
Display Options: 4.7-inch, 5.7-inch, or 6.5-inch color LCD/TFT
Typical Weight: 2.5 kg to 3.0 kg
Max RF Input Power: +30 dBm (1 W) (FSH base unit)

Models in this series

Model	Type	Interfaces	Operating Temperature	RF Input Impedance
FSH	*misc	USB host, USB device, LAN (10/100BaseT), BNC (external trigger / reference), SD card slot	0 to 50	50 Ω
FSH3	Portable	Optically coupled RS-232 / USB	0 °C to +50 °C	50 Ω
FSH6 (models 06 and 26)	Portable	Optical RS-232	0 to +50	50 Ω
FSH4	Portable	LAN, USB, SD card slot	-10 to +55	50 Ω
FSH8	Portable	USB, LAN	0 to +50 °C	50 Ω
FSH18	Portable	Optical RS-232, USB (via optical-to-USB adapter cable)	0 to 50	50 Ω

Frequency Range and Model Classifications

The primary differentiator across the FSH family is the maximum frequency range. The Rohde & Schwarz FSH3 covers 100 kHz to 3 GHz, serving basic mobile radio and lower-frequency transmitter applications. The Rohde & Schwarz FSH4 covers 9 kHz to 3.6 GHz (or 100 kHz to 3.6 GHz in Model .24), while the Rohde & Schwarz FSH6 extends this range from 100 kHz up to 6 GHz.

For higher-frequency operations, the Rohde & Schwarz FSH8 provides coverage from 9 kHz to 8 GHz (or 100 kHz to 8 GHz for version .28). Microwave link servicing is addressed by the Rohde & Schwarz FSH18, operating from 10 MHz to 18 GHz, and the base Rohde & Schwarz FSH unit, which offers options reaching up to 20 GHz.

Hardware and Measurement Options

Several models incorporate integrated tracking generators or network analysis capabilities for testing RF components, antennas, and cables. The Rohde & Schwarz FSH3 (Models 13 and 23) and the Rohde & Schwarz FSH6 (Model 26) feature tracking generator options, with the FSH6 also supporting distance-to-fault (DTF) and one-port cable loss measurements.

The Rohde & Schwarz FSH4 (Model .24) functions as a two-port network analyzer. Similarly, the Rohde & Schwarz FSH8 supports an internal tracking generator on versions .18 and .28, with the .28 version adding a built-in VSWR bridge.

Physical Specifications and Interfaces

These handheld instruments are engineered for tough environments, though physical dimensions and interfaces differ. The Rohde & Schwarz FSH3, FSH6, and FSH18 weigh 2.5 kg, while the Rohde & Schwarz FSH4 and FSH8 weigh 3 kg and measure 194 mm × 300 mm × 69 mm.

Operating temperatures vary: the FSH4 supports a wider temperature window of -10 to +55 °C, compared to the 0 to 50 °C range of the other models. Connectivity ranges from optical RS-232 interfaces on older models like the FSH6 to modern LAN, USB, and SD card storage on the FSH, FSH4, and FSH8.

Frequently asked questions

What is the battery type used across the different models?: The Rohde & Schwarz FSH3 uses an internal NiMH battery. In contrast, the Rohde & Schwarz FSH, FSH4, and FSH8 models utilize Li-ion battery technology, with the FSH8 supporting up to 4.5 hours of operating time.
How does internal memory capacity differ on the FSH18?: The Rohde & Schwarz FSH18 features dedicated setup and trace memory that can store up to 100 different configurations and trace results directly on the instrument.
What are the differences in frequency resolution and reference aging?: The Rohde & Schwarz FSH, FSH4, FSH8, and FSH18 all feature a frequency resolution of 1 Hz. Reference frequency aging is less than 1 ppm/year for the FSH4 and FSH8, and 2 ppm/year for the FSH18.