Hantek Low Frequency Magnetic Near Field Probe Kit - Precision Measurement Tools for Design Engineers

The Hantek low frequency magnetic near field probe kit (Debug Store NFPA-2; Hantek "Low Frequency Magnetic Field Probes, 9 kHz to 50 MHz") covers 9 kHz to 50 MHz with three passive H-field probes: the HNFP-5 and HNFP-6 (1 MHz to 50 MHz, about 25 mm and 10 mm resolution) and the HNFP-7 (9 kHz to 1.5 MHz, about 25 mm). Each probe connects through an SMB port and a 50 Ω cable to a spectrum analyser, oscilloscope or receiver, so you can locate magnetic-field emissions on a PCB or around a cable before a product goes for conformance testing.

Three Loop Sizes for Finding and Pinpointing a Source

Hantek sizes the loops for two stages of the same job. The larger loops are more sensitive but resolve less detail, so the HNFP-5 and HNFP-7, at about 25 mm resolution, pick up fields within 10 cm of the board and show which area is radiating. The HNFP-6 has a smaller loop, about 10 mm resolution and a detection range within 3 cm, so it is less sensitive but narrows the search down to a trace, an inductor or a connector. The probe heads are electrically isolated, and measurements are non-contact, taken close to the device under test with the probe orientation turned to find the peak.

9 kHz to 50 MHz Magnetic Near Field Coverage

The HNFP-7 covers 9 kHz to 1.5 MHz, which takes in typical switch-mode power supply switching frequencies. The HNFP-5 and HNFP-6 cover 1 MHz to 50 MHz, where switching harmonics, clock fundamentals and cable common-mode currents sit. Together the kit closes the band below 30 MHz that the Hantek high-frequency magnetic near field probes do not reach, so a board can be scanned from 9 kHz to 3 GHz with the two sets.

Connection and the Optional HNFPA-1 Preamplifier

All three probes are passive and need no power. The probe port is SMB (male). The supplied RF cable is about 1 m, SMA (male) to SMB (female), and two SMA (female) to N (male) adaptors fit an N-type analyser input.

Weak low-frequency emissions can be raised with the Hantek HNFPA-1 preamplifier: 9 kHz to 3 GHz, typical gain 30 dB, flatness ±1.5 dB and 15 dBm maximum input. It runs from 12 V DC. Hantek lists a power adaptor and a USB Type-C cable in the box, and states the amplifier can also be powered from a spectrum analyser's USB port through its USB boost cable; confirm the cable supplied before relying on USB power.

What Is in the Box

HNFP-5, HNFP-6 and HNFP-7 probes, one SMA (male) to SMB (female) RF cable about 1 m long, and two SMA (female) to N (male) adaptors. The HNFPA-1 preamplifier and SMA to SMA cables are not included.

Specifications

Limitations

• Magnetic field only. For E-field emissions, use the Hantek electric near field probes (30 MHz to 3 GHz).
• The upper limit is 50 MHz. Above 30 MHz, the Hantek high-frequency magnetic near field probes cover up to 3 GHz.
• The HNFPA-1 preamplifier is not included. Using it with the probes needs SMA (male) to SMA (male) RF cables, which you supply.

Hantek Near Field Probe Sets Compared

Typical Applications

Tracing the source of a low-frequency conducted-emission problem to a buck converter's switch node, inductor or input loop with the HNFP-5, then pinning it down with the HNFP-6. Checking the magnetic field around a power stage at its switching fundamental below 1.5 MHz with the HNFP-7. Comparing emissions before and after a layout or filter change, with the probe held at the same position and orientation.

The kit suits hardware and EMC engineers doing pre-compliance debug on switch-mode power supplies, motor drives and mixed-signal boards, who already have a spectrum analyser or oscilloscope on the bench.

Order the Hantek low frequency magnetic near field probe kit €282,95 ex VAT. Add the HNFPA-1 preamplifier if your analyser cannot see weak emissions, or ask us for a formal quotation for the full Hantek near field set. See the full near-field probe range for the high-frequency and electric sets.

Frequently Asked Questions

Which Probes Are in the Low Frequency Kit?

The three Hantek low-frequency magnetic probes: HNFP-5 and HNFP-6 (1 MHz to 50 MHz) and HNFP-7 (9 kHz to 1.5 MHz), with a 1 m SMA to SMB RF cable and two SMA to N adaptors.

Answered by John Legg, Director, Debug Store

Can I Use the Probes with an Oscilloscope Instead of a Spectrum Analyser?

Yes. Hantek states the probes connect to a spectrum analyser, oscilloscope or receiver through a 50 Ω cable. A spectrum analyser gives the frequency-domain view most EMI work needs.

Answered by John Legg, Director, Debug Store

Do I Need the HNFPA-1 Preamplifier?

Not always. The probes are passive and work directly into the analyser. The HNFPA-1 adds about 30 dB of gain when the emission is too weak to see above the noise floor.

Answered by John Legg, Director, Debug Store

Is There a Gap Between 9 kHz and 50 MHz?

No. The HNFP-7 covers 9 kHz to 1.5 MHz, and the HNFP-5 and HNFP-6 cover 1 MHz to 50 MHz, so the ranges overlap between 1 MHz and 1.5 MHz.

Answered by John Legg, Director, Debug Store

Last reviewed: 30 October 2026