Pesky noise floor

Here is demonstration of using a filter to make your rnode work again in a noisy environment. That video is the fifth of sequence. The video has a several prequels and sequels showing the route to the solution. To see the series in order, go to the link, click on Simon Phillips' icon under the video, and click on the 'videos' tab and then the chronological sequence should be shown. Alternatively, the sequence is also listed here for convenience, and addresses the issue of the noise floor when trying to use a 5 dBm (high-gain) antenna on an rnode running under MeshChat:

1. Reticulum RNode Antennas - higher gain is not always better
2. Comparing LoRa Antennas for Reticulum Meshtastic - Problem with Local Noise
3. Initial Tests of 868MHz Filter for Meshtastic and Reticulum Meshchat in 868MHz ISM Band
4. 868MHz Filter effect on Meshtastic and Reticulum Meschat received Signals
5. as linked above Filter to improve Signal Quality of 868MHz Reticulum Meshchat RNode
6. Noise Floor Indications from Reticulum or Meshtastic RNode.

The videos are a good demonstration of systematic radio diagnostic techniques and the sort of equipment one might need for that. This sort of cavity filter was used. A tinySA spectrum analyser was used, which also has a interface to a computer available, that is easy to install on Linux Mint; and has a Wiki.

If you change the antenna, and want to send messages, you need to re-start MeshChat so that a new noise floor is calculated for the new antenna, which MeshChat then uses in controlling the sending behaviour.

Last edit 03-07-2025 MMDDYYY 12:00:00 EST