@vk5qi The Sondehubs Grafana "Per-Receiver Packet Count" graph versus RS41 packet frame counter. In this case here: https://grafana.v2.sondehub.org/d/bbaa7894-e5f4-4c0d-be96-897b4ffde43b/radiosonde-telemetry-dashboard?var-Serial=V1210643&from=now-1h&to=now&orgId=1&refresh=1m