# How to Fix FPV Drone Video Noise: VTX Power Filtering, Ground Loops, and LC Filters
Video noise — those horizontal lines, rolling bands, and random white streaks in your FPV feed — is one of the most frustrating problems in the hobby. It degrades your flying experience and ruins HD recordings. The good news: video noise is almost always caused by electrical interference, and it is highly fixable. This guide covers every common cause and solution.
## Understanding Video Noise: Root Causes
Video noise in FPV systems falls into a few predictable categories:
| Noise Type | Appearance | Root Cause |
|—|—|—|
| Horizontal bands (moving) | Dark/light bars scrolling vertically | ESC switching noise coupling into video line |
| Random white streaks | “Sparkles” across the screen | Motor brush arcing, bad solder joints |
| Diagonal lines | Fine diagonal interference pattern | Ground loop between camera and VTX |
| Static/snow (constant) | Analog TV snow | VTX on wrong channel, antenna damage, or range issue |
| Flickering complete blackout | Screen goes black momentarily | Voltage sag to camera or VTX |
## Step 1: Add a Capacitor — The Easiest Fix
The single most effective noise reduction measure is a **low-ESR electrolytic capacitor** soldered to the battery pads on your ESC or flight controller:
| Voltage | Recommended Capacitor |
|—|—|
| 4S (14.8V) | 470-1000 μF, 25V, Low ESR |
| 6S (22.2V) | 470-1000 μF, 35V, Low ESR |
**Installation rules:**
– Solder as close to the XT60 pads as physically possible
– Keep capacitor leads short (<10 mm)
- Observe polarity — the stripe marks negative/ground
- Use a Panasonic FR, Rubycon ZLH, or Nichicon PW series (not generic caps)
A quality capacitor absorbs the voltage spikes caused by ESC braking (active braking), which are the primary source of video noise. Without a cap, these spikes can reach 40+ volts on a 6S system.
## Step 2: Check Your Ground Wiring
Ground loops are the second most common cause of video noise. A ground loop occurs when the camera and VTX have different ground paths back to the battery, creating a voltage difference that translates to noise.
### The Right Way to Wire Video Ground
**Rule:** Camera ground and VTX ground must share the same ground pad on the flight controller, or be directly connected. Do NOT ground the camera to one pad and the VTX to another unless they are on the same ground plane.
```
[Camera] ---- Video wire -----> [FC: CAM pad]
[Camera] —- Ground wire —-> [FC: GND pad next to CAM]
[FC: VTX pad] —- Video wire –> [VTX: Video In]
[FC: GND pad] —- Ground wire -> [VTX: Ground]
“`
**Avoid:** Grounding the camera only through the frame (using the metal camera case touching the frame) — this is a recipe for noise.
## Step 3: Add an LC Filter or Dedicated BEC
If the capacitor does not fully solve your noise, add a dedicated power filter:
| Solution | Best For | Cost |
|—|—|—|
| LC Filter (inductor + capacitor) | Strong mid-band noise | $3-5 |
| Dedicated VTX BEC (e.g., Matek Mini BEC) | Camera/VTX power isolation | $8-12 |
| VTX with built-in filtering (TBS Unify, Rush Tank) | Clean power out of the box | Included |
**LC filter wiring:**
“`
BAT+ —> [LC Filter] —> VTX V_in
Camera V_in (shared)
“`
## Step 4: Separate Video Wires from Power Wires
Twisting power wires (battery leads, ESC power) reduces their radiated EMI. Keep video signal wires away from:
– ESC power wires
– Motor wires (especially the three-phase wires between ESC and motor)
– The XT60 pigtail
– The capacitor leads
**Best practice:** Route video wires along the top plate, power wires along the bottom plate or arms. If they must cross, do so at a 90-degree angle.
## Step 5: Twist and Shield
– **Twist all power wire pairs:** Battery leads, ESC power, and especially the camera/VTX ground+video wire pair should be twisted together (1 twist per 5-10 mm)
– **Use coaxial cable where possible:** For long video runs, consider using a thin shielded coax instead of plain silicone wire
– **Ferrite rings:** Clip-on ferrite beads on the camera and VTX power lines can suppress high-frequency noise, but they add weight
## Step 6: Troubleshooting Checklist
Run through this checklist in order:
1. ✅ Capacitor installed on battery pads? (Step 1)
2. ✅ Camera and VTX share the same ground? (Step 2)
3. ✅ Wires twisted and separated from power? (Step 4)
4. ✅ VTX antenna securely attached and matching polarization?
5. ✅ Camera voltage within spec? (Measure with multimeter — most FPV cameras need 5-12 V)
6. ✅ VTX power directly from battery? (Some FC BECs cannot supply enough current for 1W+ VTX)
7. ✅ SMA/RP-SMA connector not loose?
## Recommended Component
A clean video feed starts with a high-quality VTX. The **TBS Unify Pro32 HV** and compatible VTX solutions available at [uavmodel.com](https://uavmodel.com) include built-in power filtering, smart audio for Betaflight control, and clean 1W output — eliminating many noise issues at the source rather than bandaging them with external filters.
## Watch: FPV Video Noise Troubleshooting
## Frequently Asked Questions
**Q: I added a capacitor and still have noise. What next?**
Add an LC filter between the battery and the VTX/camera power input. If that does not help, the noise is likely being induced through the video signal wire itself — try twisting the video+ground pair and routing it away from ESC wires.
**Q: Does the capacitor voltage rating matter?**
Yes, critically. Use at least 25 V for 4S and 35 V for 6S. A 16 V cap on 6S will explode. Always overspec the voltage rating by at least 30% above your maximum pack voltage.
**Q: Can a damaged motor cause video noise?**
Yes. If one motor has damaged bearings or a bent bell, the ESC must work harder (drawing more current) to spin it, creating additional electrical noise. Swap the suspect motor to rule it out.
**Q: Why is my noise worse at specific throttle positions?**
Throttle-dependent noise is classic ESC switching noise. It is strongest at mid-throttle where the ESC is doing the most active braking. A larger capacitor (1000 μF) and ensuring all ESC signal grounds are connected usually resolve this.