Video Static & Noise
Video problems diagnose by when they appear, not what they look like. The same snow can be electrical (your own quad polluting its camera), RF (the link running out of budget) or mechanical (a connector) — and the timing separates them.
The branches, with the physics
Throttle-synced noise is your own power system talking over the video. Motor switching pulls fast current spikes; without a capacitor they ride the rails into the VTX and camera. The fix hierarchy, in order of hit rate: the low-ESR capacitor on the ESC pack pads (Module 6 calls it the cheapest reliability upgrade in FPV) → a single clean ground path camera–FC–VTX (ground loops inject exactly this noise — Module 10) → VTX powered from a filtered 9–10 V pad, never raw pack voltage (5″ build wiring plan).
Distance noise is arithmetic, not mystery: the video link spends its budget and analog degrades into snow (digital instead hits its cliff — Goggles explains the difference). Antennas are the honest lever; the link-budget calculator and Module 1 put numbers on it. A damaged antenna — post-crash SMA with a cracked element — silently costs more dB than a VTX power step gains.
Bench noise with motors off is wiring: a half-seated camera connector, a cold joint on the video line, or a VTX cooking itself at high power with no airflow (they expect prop wash; bench-test at low power or pit mode).
Analog-specific quick wins
| Symptom | Cause | Fix |
|---|---|---|
| Rolling horizontal bands | Ground loop | One ground path, camera grounded at the FC (Module 10) |
| Snow that worsens on punch-out | Voltage sag reaching the VTX | Filtered VTX rail + capacitor (Module 6) |
| Another pilot appears in your feed | Same channel or its harmonic | Coordinate channels — the band plan exists for this (VTX) |
| Fine after a minute, bad when hot | VTX thermal throttling | Airflow over the VTX, or lower power (VTX) |
The goggle DVR is the diagnostic instrument here — noise you can rewatch is noise you can classify by its timing (Goggles). "It looked bad" is not data; the DVR clip is.