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JonM

Video interference problem

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Hi All, Im having some trouble with video interference on my plane. The video signal is fine until the motor is started at which time horizontal lines start to flicker on the image. Ive move the ESC as far away from the Tx as possible, but that places it directly under the camera.

Is there anything I can use to shield some components and prevent this problem?

Thanks... Jon

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Your complaint is common to users that attempt to share the motor battery or have a video Tx that cannot tolerate mechanical vibration.

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If your have audio try removing the microphone and see if it helps.

Terry

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Yup, the microphone would be something that causes those problems too. I have dealt with that interference issue on a couple of systems.

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I may have to try isolating my transmitter from vibration now, as I'm getting the horizontal lines in my video as well. I've already done away with the mic, and I'm using a seperate battery. I never knew that vibrasion could cause it. I've got the transmitter mounted pretty solidly to the plane too.

Thanks for the tips!

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I may have to try isolating my transmitter from vibration now, as I'm getting the horizontal lines in my video as well.

I noticed the noise in the video you recently posted. FWIW, some video Tx's (especially low cost Hong Kong/eBay versions) are problematic with mechanical vibration, even after extraordinary efforts to damp them.

If the cover on the RF sardine can is not soldered in place, then it can also be a source of vibration induced video noise. Microscopic movement of the components is another source of problems. With microwave designs, everything matters.

Hopefully yours is one that can be tamed without going crazy.

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Just a thought, I had the same problem with one of my planes and added the 3 capacitors to the motor and RF beads to the servo cables and eliminated all of it.

Lee

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OK to help you folks with those darn lines. You can try Ferrite Beads for RFI radio frequency interference supperession. Look at www.palomar-engineers.com And other sites on the web You can install them on all your power leads, motor, radio,tx and rx etc. Good Luck. I'm just getting started .

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Hi

Did I read correctly that it is impossible to get away from interference if using the motor battery to power the camera tx?

I have rigged mine this way - and I have wavy hoizontal white lines.

Is the only fix using a separate battery?

Thanks

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I run a Super Tigre 61 ABC on a Sig Kadet Senior. The camera is mounted on the wing secured to the wing with vesco elastic damping material. THe transmitter is a 600 mw BW that is mounted in the fuse just behind the wing saddle. THe SMA goes thru the covering and secures to a 1" x 4" plywood that is isolated from the fuse with rubber washers.

My video was terrible until I performed all this. I still have slight video vibration, but I beleive a redisigned camera mount should fix this.

My thought is that most of these problems are vibration related.

Maybe we should ask folks to post there vibration damping pictures?

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Sharing the video gear with the e-motor pack is possible, but sometimes curing the motor commutation noise is not practical. A separate battery is much easier for the average Joe.

As has been mentioned, some video Tx's suffer from mechanical vibration too. Easiest way to tell where the noise source is from is to try a dedicated pack; if the video problems go away then you will know the cause. If not, then assume vibration or evil spirits.

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The problem could also come from the connectors, I got this problem on my glow engines planes, I wrapped connector in foam and kept it from moving freely.

On my glow planes, the cam and tx was solidely mounted to the planes with nothing to dampen vibration, it's the best way I founded to get a clear video. Never lost a camera due to high vibration. It work also with four stroke motor.

In my Easystar, only one battery is use, and in my Babycat I don't see problem by using only one batt, (the duct fan is powerfull). I don't understand why it work well for me. Other also use only one batt without problem. I think the key is to use 5V cam and tx and voltage regulator or in the wiring.

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How would you go about splitting out 12v from the main battery vrflyer?

Just use a Y cable of sorts?

Edited by Mark Harris

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I had the horizontal lines on my Twinstar2 and switching from brushed to BL motors cleared the problem. Also using a separate battery cleared most of it before the BL change of motors. I cut 8 oz off total weight by going with a 2S lipo I had been using 7 cell NiMh. All worked OK till my battery overheated during charge.Was using 7X4 props on speed 480 motors. Really works good for FPV flights except for minor interference. I have 3 TS 2 that I alternate using depending on cameras etc. Great plane a real workhorse.

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I know this is an old thread, but the topic is still relevant. I was able to solve my video noise problem with a low pass filter I made. Here is the link: Filter See posts 70-75. The filter goes between the battery and the FPV equipment.

Edited by PrplMshrm

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Yep a low pass filter is often added to the SMPS design at the start but I have found the values vari depending on the load, well done for making it work.

I use low ESR SMT capacitors for keeping the size down.

Terry

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I use low ESR SMT capacitors for keeping the size down.

Same here, but I toss in some L's too. :)

I ran into nasty DC-DC switcher induced video noise problems a few years ago when trying out Dimension Engineering's nifty switcher Vregs. I had to use a pair of LC filters to kill the visible lines. I got tired of hand crafting the filters on copper clad so I eventually created a little PC board instead. The nice thing is that I only have to remove the aluminum heatsink bracket from the DE switcher; otherwise it is essentially stock. All the dirty work is on the custom PCB.

Top side showing the DE Switcher, minus its usual heatsink.

post-2-1231909166_thumb.jpg

Back side showing the LC filter components.

post-2-1231909172_thumb.jpg

Eventually the DE web site posted some information on how to reduce the Vreg's ripple noise (it was published shortly after I reported my noise issues to them). I recall they show a couple cures, one with just a cap and another that suggests a inductor and cap (LC) filter. From my experience the latter was needed, but times two: one LC arrangement on the Vreg input and another one on the output (that is how the little filter PCB is configured). Even so, I don't share the motor battery with the video gear -- Video goodies are powered by a dedicated battery supply.

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Even so, I don't share the motor battery with the video gear -- Video goodies are powered by a dedicated battery supply.

In my FPV funjet, the main battery powers everything. So far, so good. Waiting on my new rx and video recorder before I can test fly it. I don't want to crash and not even have a video to show for it, LOL. :D

By the way, is interference the reason you use separate batteries, or some other reason?

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One of the reasons.. another being that when you realise your flight battery died on you a bit earlier than expected you still have video to fly back home thanks to a separate one...

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Kilrah has a good point. :) I don't share the video battery with the motor/RC system battery because it increases the chances of visible video noise, plus has caused EMI/RFI issues on my 72MHz R/C receivers. But, if your setup is working great on a shared battery then you are good to go. Just be sure to range check, with the video gear on, EVERYTIME you go to fly; I had one bite me long after I thought things were fine.

The only time a shared battery has worked for me is when the video gear was 5V based and my motor/flight battery was twice that voltage (that way motor commutation ripple won't cause video noise). But overall, because of some bad past experiences, I use the KISS principle and keep their power sources isolated.

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