# Fixing FPV Video Noise: Capacitor Placement and Ground Loops
If you are experiencing diagonal lines, flickering, or severe static in your FPV video feed when applying throttle, you are likely dealing with electrical noise. High-performance brushless motors and ESCs generate significant voltage spikes that can disrupt sensitive VTX and camera components.
In this technical guide, we will troubleshoot FPV video noise, explore the importance of Low ESR capacitors, and correctly diagnose ground loops in your drone build.
## Identifying the Source of the Noise
Before tearing apart your drone, use this checklist to diagnose the noise:
* **Noise only on throttle punches:** Indicates voltage spikes and lack of capacitance.
* **Constant static even when disarmed:** Usually a loose antenna, damaged VTX, or a ground loop.
* **Black screen with OSD:** Camera wiring issue or dead camera.
* **Snowy screen (no OSD):** VTX channel mismatch, low output power, or burned VTX.
### Component Comparison: Capacitor Types
Not all capacitors are created equal. FPV requires **Low ESR (Equivalent Series Resistance)** capacitors to handle rapid voltage changes.
| Feature | Low ESR Capacitor | Standard Capacitor |
| :— | :— | :— |
| **Voltage Spike Handling** | Excellent | Poor |
| **Heat Dissipation** | High | Low (Prone to popping) |
| **Cost** | ~$1-2 each | ~$0.10 each |
| **Best Application** | FPV ESCs / PDBs | Low-frequency electronics |
## The Solution: Proper Capacitor Placement
Adding a capacitor to your main battery leads is the most effective way to clean up your video feed and protect your electronics.
**Pro Tip:** For 6S builds, we highly recommend upgrading to the **[UAVModel Premium Low ESR 1000uF 35V Capacitor Pack](https://www.uavmodel.com)**. These are specifically manufactured to absorb extreme ESC noise and prevent premature VTX burnouts, ensuring a crystal-clear video feed.
### How to Install
1. **Select the correct size:** 1000uF 35V is standard for 6S. 470uF 25V is acceptable for 4S.
2. **Keep legs short:** The longer the legs of the capacitor, the higher the resistance. Solder as close to the ESC battery pads as possible.
3. **Check polarity:** Ensure the striped side (negative) goes to the ground pad!
## Visual Troubleshooting Guide