Gigahertz Solutions HF35C High-Frequency EMF Meter

Easy RF Measurement for Home and Everyday Use

The Gigahertz Solutions HF35C is a high-frequency EMF meter for detecting and measuring radio-frequency (RF) electromagnetic fields from 800 MHz to 2.7 GHz.

It combines a logarithmic-periodic (LogPer) measuring antenna with frequency-compensated RF measurement, switchable peak and average readings, and audio analysis. This makes it possible to measure the level of RF radiation present while also investigating the characteristics and direction of detected sources.

The HF35C is intended for practical RF measurements in homes, workplaces and other environments where mobile communications, Wi-Fi, DECT and other radio-frequency sources may be present.

What Can the HF35C Measure?

The HF35C measures power flux density across a frequency range of 800 MHz to 2.7 GHz.

The measurement range is 0.1 to 1,999 µW/m², with the display providing a resolution of 0.1 µW/m².

Within its frequency range, the HF35C can measure RF signals from sources including:

• Mobile radio networks
• GSM
• UMTS / 3G
• LTE / 4G
• Sub-3-GHz 5G frequencies within the meter's range
• WLAN / Wi-Fi
• DECT cordless phones
• Radar

The HF35C does not cover the entire radio-frequency spectrum. Its specified operating range is 800 MHz–2.7 GHz, so frequencies outside this range require a different measuring instrument.

Identifying RF Sources with Audio Analysis

The HF35C includes an audio analysis function that can assist in identifying certain types of pulsed RF radiation.

The audio signal is proportional to the modulation frequency and field strength of the detected radiation. This can provide additional information alongside the numerical measurement on the display.

The manufacturer gives examples including GSM, DECT and other pulsed RF sources. The audio output can help distinguish different signal characteristics when investigating an RF environment.

Directional Measurement with the LogPer Antenna

The HF35C uses an external logarithmic-periodic (LogPer) measuring antenna. Unlike compact RF meters with an integrated antenna, the external antenna provides directional information that can be useful when investigating the location of an RF source.

By changing the orientation of the antenna and observing the measured level, it is possible to investigate the direction from which a stronger RF signal is arriving.

The HF35C can be used for measurements both indoors and outdoors. When measuring outside, the instrument should be protected from moisture.

Frequency-Compensated RF Measurement

The HF35C is fully frequency compensated within its specified frequency range. The manufacturer states that neither particular parts of the frequency range are deliberately over-weighted nor under-weighted or ignored.

The measurement technology also displays the sum of the RF radiation present at the measurement location, rather than simply selecting the strongest individual frequency.

This is relevant when several RF sources are present at the same time. A broadband measurement can therefore represent the combined RF field detected at the measurement location.

Peak and Average Measurements

The HF35C provides switchable peak and average measurement.

RF signals can vary with time, particularly when dealing with transmitting devices that operate intermittently. Having both peak and average readings available allows the user to examine the measured field in different ways.

Sensitivity and Measurement Range

The HF35C has a display resolution of 0.1 µW/m² and a maximum displayed measurement of 1,999 µW/m².

The manufacturer specifies a basic accuracy of ±6 dB including linearity error. The stated zero-point deviation and special digitising error, referred to as "rollover", is ±9 digits.

This measurement range allows the HF35C to be used for investigating relatively low RF field levels as well as higher levels within the instrument's specified range.

Where Can the HF35C Be Used?

The HF35C can be used to investigate high-frequency electromagnetic fields in a range of environments, including:

• Houses and flats
• Bedrooms and living areas
• Offices and workplaces
• Buildings with Wi-Fi networks
• Locations with DECT cordless phones
• Areas affected by mobile communication signals
• Locations where intermittent RF sources need to be investigated
• Indoor and outdoor environments

The directional antenna is useful when the purpose of a measurement is not only to establish that RF radiation is present, but also to investigate where a stronger source may be located.

The HF35C can also be used to compare measurements taken at different times or before and after changes to an environment, provided that the measurement conditions are comparable.

Technical Specifications

What's Included?

• Gigahertz Solutions HF35C measuring device
• Plug-on LogPer antenna with antenna cable
• 9 V alkaline manganese battery
• Detailed operating instructions with background information

HF35C for UK RF and EMF Measurements

The HF35C provides a practical way to measure high-frequency electromagnetic fields across the 800 MHz-2.7 GHz range. Its external LogPer antenna provides directional measurement capability, while frequency compensation, peak and average readings and audio analysis provide additional information when investigating RF sources.

For UK users, the specified frequency range covers many commonly encountered RF sources, including mobile communications, Wi-Fi, DECT and relevant Sub-3-GHz 5G frequencies that fall within the meter's operating range.

If you need to measure frequencies below 800 MHz or above 2.7 GHz, a meter with a different frequency range should be selected.

HF35C or HF38B - Which Meter Should You Choose?

Both the HF35C and HF38B are high-frequency RF meters with a directional LogPer antenna, frequency-compensated measurement, audio analysis, and switchable peak and average readings. The main difference is the level of sensitivity and additional measurement functions offered by the HF38B.

Choose the HF35C if you want a straightforward RF meter for investigating everyday sources of high-frequency electromagnetic radiation in the home or workplace. It provides the essential measurement functions without the additional sensitivity and Peak Hold function of the HF38B.

Choose the HF38B if you need greater sensitivity, a wider lower-frequency range, a higher maximum measurement range and Peak Hold. It is the better choice when more detailed RF measurements or comparisons are required.