Satellites dropped to crap after camera/gimbal replacement

[robinbuzios]

After 2 months and 2 failed repair attempts, I ended up with a new camera/gimbal unit. Everything looked AOK after installing and recalibrating. Took it to my usual flying field and waited for home lock, which I never got. It wouldn't pick up more than 5 satellites, where before I'd get 8 or 10 within one minute of powering up. I had low satellite numbers when first got the phantom 3 months ago, so I did the gps aluminum foil mod which worked like a charm at the time.

I'm sure it's the camera that's causing the drop because did a quick field test and removed camera/gimbal cables to disable the electronics, powered up again, and sure enough I got home lock and green only blinks within a minute. Couldn't get an exact number because I had no telemetry, but the problem was obvious. This is all before I even switched on the video, which probably would have caused a further drop in sats.

Is it possible that different units of the same vision plus cameras are emitting varying levels of interference? I still have aluminum tape from the last mod... does anyone know of a thread or have a suggestion on how to further isolate the the camera from the gps module? I'll start rereading that huge foil mod thread again to see if it addresses this specifically, but I also wanted to share this experience to see if anyone has any insights as to what may be happening. I really want to get back to flying!

 

[CityZen]

Re: Satellites dropped to crap after camera/gimbal replaceme

The wifi unit and its cables (and perhaps the gimbal board) are certainly a source of interference. You can't compare the performance with/without the gimbal attached, since it will certainly be worse with the gimbal attached and operating. You can only compare from when you had the gimbal before to having the gimbal now. Note that when the gimbal is not attached, the wifi unit receives no power. I wouldn't expect changing the gimbal to make any significant difference in interference, though.

As far as reducing the interference, there are several approaches:
- the tin-foil mod over the GPS module that you've done: make sure the GPS cable is also shielded.
- the tin-foil mod on the bottom of the Phantom.
- installing various toroidal chokes on the gimbal cables like DJI did lately.
- shielding the gimbal cables.

 

[robinbuzios]

Re: Satellites dropped to crap after camera/gimbal replaceme

Thanks cityzen for the reply. I didn't know about the bottom tin foil mod, I'm assuming it's in the original tin foil mod thread. The only thing I can't do immediately will be the toroidal chokes since I'm in the middle of nowhere. As far as comparing the difference between the old gimbal and the new... I did the mod while the old gimbal was still attached. At the time the improvement was significant, which is when I was getting the 8 to 10 sats. This is why this issue is so baffling. Why should the new gimbal create so much more interference compared to the new one? The only other possibility that I can point to would be an upside crash from 4 feet up after hitting a bush which happened just before the new gimbal arrived. No visible damage from that, but I popped the lid open anyway to do a clean-up (I live in sand) and to check for loose contacts. Should I tear up the old foil mod and check the gps module itself? I'll do the other mods first, then check back.