I was flying this fettec 2.5" yesterday and while I was in easy range with good LOS the video just went completely black for 1 second and then came back. The same thing happened 2 days ago, though at the time I had assumed it was interference. I now know it is related to this specific quad and not my goggle or surroundings.

The issues arises at 30 seconds in the video:


Thanks for your thoughts!

even the osd from the goggle disappered, that could be an issue by the vrx - your goggles or the module

i would suggest to do gently flights in low range as you did, explore if it was a single fail or does start to become regular

Yes, I was initially blaming my analog module on the HDZero goggles, but I haven't had this issue with any of my other analog quads which I flew a lot of on both of these days, and twice have had it with this one in low intensity flying situations, which led me to think it's the quad.

Edited just to point out that I did still have the hdzero osd, but the quad analog osd was out. But that only shows up when the quad is connected, not while scanning channels or connecting to signal. I'll probably disassemble the quad and see if a vtx wire is loose or something?

What are all those bars on the top of your OSD, are they overlaid by your analog module or by the FC? As they also cut out, if they are from the module then there maybe an issue with the module.

Those bars are FC OSD. This quad has a very poorly mounted vtx and it's possible it's touching something else or in some other way being disturbed. Will disassemble and assess.
If a vtx is directly touching a FC can issues other than heat exposure arise?

Okay, disassembled, inspected for loose connections(though I have novice eyes), it was actually the loose elrs receiver that was touching the vtx, so I placed a piece of foam between those two and reassembled. Flew a single pack with no problems, so I'm hoping it was just that dangling receiver briefly making a connection where it should not have or something? Shootin in the dark here.
We'll see if the problem arises again over the next few packs.

Did you throw a cap on the power leads? Those horizontal bands when you throttle up are more than likely due to dirty power, ie, surges and similar. Or maybe a bigger cap if you already have one.

(21-Jul-2023, 01:34 AM)Pathfinder075 Wrote: Did you throw a cap on the power leads? Those horizontal bands when you throttle up are more than likely due to dirty power, ie, surges and similar. Or maybe a bigger cap if you already have one.

No, it's a used build I bought. Admittedly I don't know anything about this, how do I determine what kind of cap to solder in?

What lipo cell count are you using?

6S = 35V 1000uF or 680uF or 470uF
5S = 35V 680uF or 470uF
4S = 25V 470uF or 330uF
3S = 16V 470uF or 330uF
2S = 10V 330uF or 100uF (commonly found in FPV shops pre-mounted to an XT30 power cable)
1S = don't bother, but you could use a 6.3V 220uF if you wanted to, they are small enough to put on a 5A AIO

That's my rule of thumb, other might have different opinions.

I use Panasonic Caps for mine.

Thanks, that's helpful. How do you deal with a drone that you may fly different cell counts on? I have 2 that I fly both 3s and 4s packs on.

Edited: I found on Oscar Liang's page that you lean towards the higher voltage rating if unsure. Makes sense.
I think I will definitely install one of these and see what the effects are. Thanks for the idea!

(21-Jul-2023, 03:13 AM)FPVme Wrote: Thanks, that's helpful.  How do you deal with a drone that you may fly different cell counts on?  I have 2 that I fly both 3s and 4s packs on.

Edited: I found on Oscar Liang's page that you lean towards the higher voltage rating if unsure.  Makes sense.
I think I will definitely install one of these and see what the effects are.  Thanks for the idea!

Just a note on the capacitors. Most capacitors will help some, but low ESR capacitors will eat the ripples considerably better. They cost just a little more, but $2-3 each isn't an awful lot if you're doing FPV.

These are the ones I use. It's a UK seller, so you would need to find a source state side.

https://www.ebay.co.uk/itm/351313817882

But the ones I use are Ultra Low ESR.

My capacitors have arrived, do I just solder the cap to the same pads that the power cable is soldered to? Negative to negative positive to positive?
Thanks!

Yes. Make sure you get the legs the right way. If you solder it the wrong way it will go bang.

If you are lacking space for whatever reason you could solder wires to the pads instead and solder the capacitor to the wires and secure it somewhere else. If doing it this way, try and keep the wire lengths short.

Just for ease of attachment I soldered to the battery connector end of the wires, that way I didn't bother to disassemble the drone.
All seems well and I am pretty sure there is less interference in the video. Gotta swap my props as they are not fresh and I think are introducing some wobble or water to the image, but the 'static' seems greatly diminished.
I'm really glad you noticed that static, it's something I can look out for now, and now I've learned a lot more about capacitors than I knew a week ago, thanks!