signal
10 posts
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Why Radio Speaks in Decibels
Understanding dBm from first principles: where the decibel came from, why radio power is logarithmic, and the physics that sets the noise floor.
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Choosing a LoRa Dev Board for MeshCore
LoRa dev board comparison for MeshCore: Heltec V3, Heltec V4, and RAK WisBlock 4631. TX power, sleep current, and the use case each handles best.
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Every Node Heard It Twice
Duplicate packet floods in a LoRa mesh waste airtime and hide real problems. What causes them, how MeshCore suppresses them, and how to read Live Packets.
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Measuring Your LoRa Link Margin
Measure LoRa link margin from SNR data. Target 15–20 dB above the demodulation floor for outdoor mesh. Track trends to catch margin erosion before failure.
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Measuring SNR on a LoRa Mesh
How to measure SNR on a LoRa mesh: what the number means, where Waev surfaces it per observed link, and how to use it to find links worth fixing.
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The Chatty Node
How to spot and fix a chatty node on a LoRa mesh: diagnosing too-frequent adverts in Live Packets, identifying the source node, and the CLI fix.
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Tuning a LoRa Antenna with a NanoVNA
How to measure and interpret SWR at 915 MHz using a NanoVNA: what the numbers mean, what a well-matched LoRa antenna looks like, and what to do when the dip is at the wrong frequency.
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What dBm Actually Measures
What is dBm? It is an absolute radio power level referenced to 1 milliwatt: the unit behind every SNR reading, transmit spec, and antenna gain calculation.
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What Is SNR in LoRa Radio?
SNR (Signal-to-Noise Ratio) is the dB margin above the noise floor. This covers what the values mean for LoRa and why negative SNR still decodes in MeshCore.
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Why Mesh Packets Disappear
Four reasons a LoRa mesh packet disappears: RF margin, collision, duty-cycle hold, and coverage gap. How to tell them apart in Live Packets.
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