Added LC filter but see no difference

[annikk.exe]

Hi folks, I';m hoping someone can advise me on this..

I get a lot of black horizontal lines on my video when the motors are running.

I';ve heard this is due to the board cam power supply picking up fragments of the AC power as interference, and that this can be alleviated by using an LC Filter.
I was able to witness the results first hand when I looked at DirtyHarry';s video feed - it was MUCH cleaner and nicer looking than mine.

Inspired, I decided to construct my own LC Filter and Harry kindly sent links to the cap and inductor he used on his.
I followed his wiring instructions and also watched the Power Filter video on RCModelReviews youtube channel.

After getting everything soldered together and plugged back in, I';ve tried a bunch of test flights.  The video signal looks exactly as it did before - black lines are still there.

What did I do wrong?


Here is how I wired things up:


There is about 4cm of wire from the Capacitor to the board cam';s plug.
I may have applied some excessive amounts of pressure to the cap and inductor while fitting the heatshrink over them.
Could either of these be the cause of the issue?
Is my wiring correct?

[nub]

wiring looks ok i think

what about power for the VTx?

adding a diode on the positive wire before the inductor can improve the filters perfomance from what i remember.

[annikk.exe]

Power for the VTX comes straight from the PDB.  It does go via a "t-junction" of wires, the other side of the T goes to the rear LEDs.
Was I supposed to filter the VTX power instead of the board cam power?

::bungles forward through the darkness::

[DarkButterfly]

Mine looks like this because I use a piece of servo lead and looped the positive and negative wires 5 times through a ferrite ring.
The camera power is also taken from the output of the LC filter.

I noticed a instant difference, no more horizontal lines.

[annikk.exe]

Okay, so I guess I need to add an inductor in series on the negative wire too.. and bring in the power from the filter to the VTX.
I will try. :>  Thanks.

[bazzerh]

buy some ferrite rings from ebay. where your fpv gear comes off the pdb wrap the +v wire around the ring as many times as possible. split that wire for your cam and vtx, unless your vtx supplies the cam. if there are still lines then place a cap close to the ferrite ring bridging the + and - lines for your fpv gear.  watch the polarity of course.

try to keep all your fpv wires away from anything else, especially esc power lines.

the worst noise ive had was using a pdb on a tarot 250 where the signal and power lines run through the pdb itself. must have been designed by the tarot tea boy.

[dirtyharry]

I run my VTX and camera from the filter I told you about , which seams to do the trick. I have used ferrite rings before and found sometimes its better to rap one wire through the ring as raping both can transfer interference between the two. The 390uh inductor is the same as a ferrite ring , just lighter , but it can only filter the supply up to 450mah.

If you want a really really clean video have a low ripple linear voltage regulator in there , unfortunately they give off lots of heat.