Both electrical motor and ESC are source of electrical noise that influences all devices connected to the same battery. This is why, very often, on airplanes or big multirotors FPV circuit is powered from separate battery. On small or medium drones this can be hard to archive: additional weight will influence both flight performance and flight time. So, when your setup is suffering from a power noise manifesting itself as vertical bars or other image distortions on goggles/monitor, you can do 3 things:

  • use separate battery to power camera and video TX,
  • cut the noise using LC low-pass power filter.

I would choose low-pass filter. Cheaper and lighter. You can buy one for a few dollars/euros or make 10 by yourself for the same price.

LC power noise filter for FPV

You will need:

  • 100 uH (100 micro Henr) inductor. 1A current will be more that enough. I use 0.8A, 0.5A will be fine too,
  • Schottky diode. Any witch enough current and voltage will do. Just pick something with at least 1A and 40V and and it will be great,
  • 100 uF (100 micro Farad) electrolytic capacitor. Bigger capacitor would be even better, but it will grow in size. 100 uF is a compromise.

An that's all. You can build it as "in air - on cable" version. Not a problem. I used fragment of universal PCB and created something like this:

FPV power noise LC low-pass filter

Just connect is as close to camera as possible and at least some (hopefully all) power noise will be eliminated.