Problems with FPV Video Signal Cutting out, and w/ TBS Unify Pro Higher Power Levels

[ludwant]

Ok, update: I paralleled the OSD and Unify with the Naze off the BEC, and I'm getting really grainy footage; the writing from the OSD is grainy too, and the colors from the camera are very weird. List of current connections:

The camera positive is wired to the battery positive
The camera Ground is wired to the OSD
The camera video is wired to the OSD
The UBEC positive Vin is wired to the battery positive
The UBEC negative Vin is wired to the battery negative
The UBEC positive Vout (5V) is wired to the 5V rail (extra motor pins) on Naze, the power to the Unify, and the OSD power
The UBEC negative Vout is wired to the ground rail on your Naze, the OSD negative, and the Unify negative
The Unify video is wired to the OSD

 

[LitterBug]

Are you sure your VTX and goggles are on the same Band and Channel?

LB

 

[PsyBorg]

You video is crappy cause you are direct off the battery mate. You need to power that off the vtx that has filters or at the very least off the ubec so it gets cleaner power. You are gonna get all kinds of motor noise and more so in the higher voltage range of the camera. The lower the voltage you can run things off the better they will be and less susceptible to the large current fluctuations.

EDIT: Oh and running an unshielded camera to vTX wire anywhere near that birds nest that is producing one massive pulsing magnetic field will cause major issues as well.

 

[ludwant]

Ok, so I should wrap my wires in electrical tape to reduce the magnetic field, and run the camera off the UBEC. The camera does say it is rated for 5-17V though... is it the fluctuations of voltage to the camera that is causing the video to be so bad?

 

[ludwant]

Ok, I've paralleled the camera off the UBEC as well, and that seems to have fixed it! Video and OSD overlay is clear as day, even when the Unify is transmitting on 200mW and the motors are on almost full throttle. I'm charging batteries right now for some test flights. Thank you so much for all the help guys! I really appreciate it.

 

[PsyBorg]

I am going to go out on a limb and say you have very little electronics knowledge here. If I am wrong I am sorry...

Electrical tape will do nothing to isolate the video signal. Magnetic waves can penetrate a lot of materials. Think of taking two magnets and using one under a table to drag the other around on top of the table.. or a piece of paper. The wire has to be shielded. Think about antenna wires where the braid surrounds the core and gets grounded. Same principle.

As for the wavy video signal several things could be happening. One is the above magnetic induction. The other is unfiltered DC voltage which is what you have going on as well. By grounding to the osd you only grounded the video signal. Only having the positive power lead run to the camera you have an open loop on the power side so every time voltage is pulsed by the esc's the camera gets a little of that up and down power surging which will produce lines in the video. Faster pulsing= more lines and distortion. IF you power direct off the main feed run a ground to that as well.

In your quad you want all of your wires to be as short as possible so there is less material for unwanted signals to be injected. Second you do not want any alternating or pulsing wires to run parallel to other wires as this will create that magnetic field and inject signals. Lastly when ever wires (specifically signal wires) have to cross any power wires it is best they cross at 90 degree angles if possible.

Some ways to cut down on signal injection is to twist wires sets to make the ground wire act as shielding so any injected signals can go to ground. I am sure you have seen this done on many build videos and this is why.

Hopefully this will help you clean up your signal issues and give you a better flight experience.