NMRF FBP-902S Bandpass Filter

NMRF | Part: FBP-902S

Tiny bandpass filter mistuned for the US ISM band.

Comments from the Austin Mesh Community

Not recommended for obvious reasons.

Specs

Brand

NMRF

Part Number

FBP-902S

Filter Type

Bandpass

Connectors

SMA Male + SMA Female

Loss at Meshtastic (906.875 MHz)

16.17 dB

Loss at MeshCore (910.525 MHz)

19.25 dB

Return Loss at Meshtastic

1.4 dB

Return Loss at MeshCore

0.9 dB

3 dB Passband

888.5-899.2 MHz (10.7 MHz)

Dimensions

34 x 17 x 8 mm

Test Results

This page collects 2-port VNA measurements of one unit of the NMRF FBP-902S Bandpass Filter, measured firsthand by the mesh community (KG5HZC). Every sweep is charted below and downloadable as a Touchstone (.s2p) file. Measured 3 dB passband is 888.5-899.2 MHz (10.7 MHz wide).

Test 1 (KG5HZC)

At Mesh Operating Frequencies

Meshtastic (906.875 MHz)

Loss: 16.17 dB

Return loss: 1.4 dB

MeshCore (910.525 MHz)

Loss: 19.25 dB

Return loss: 0.9 dB

3 dB passband: 888.5-899.2 MHz (10.7 MHz wide), minimum loss 6.22 dB at 892.2 MHz.

Out-of-Band Rejection

433 MHz (70cm ham / ISM)46.3 dB

700 MHz (LTE 700)46.7 dB

824 MHz (Cellular uplink)42.8 dB

894 MHz (Cellular downlink)6.7 dB

930 MHz (Pagers)49.9 dB

960 MHz (Fixed links)44.6 dB

1090 MHz (ADS-B)54.1 dB

Notes from test

Measured passband is centered near 892 MHz, well below the 902-928 MHz ISM band, with 14-19 dB of loss and a poor match at Meshtastic and MeshCore frequencies.

Tested By

Tommy Ekstrand, KG5HZC on 2026-07-11

Download .s2p (902-928 MHz, 101 points)Download .s2p (870-930 MHz, 101 points)Download .s2p (430-1500 MHz, 101 points)

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