WKM>Z15>iOSD>AVL58 frustrating and intermittent error

[Davidhippo]

Hi all, thanks in advance for any advice you can offer.

I have an s800 with WKM, Z15G (with secraft adaptor holding a GH3) The GH3 plums through the zemnuse to an iosd and onto an AVL58 to send video. It's taken MONTHS to smooth out the vibes but I'm now getting super smooth images from it, even in high winds.

My problem is a gradual degradation of the video downlink, now to the point where it's unusable....

All was working fine, then initially the iOSD output, data superimposed over the video started to drop out (I'd still get the image coming through, but the superimposed data was lost) The data is still there if I switch to the input 2, but obviously no video over it. Switch back to input 1 and the image is there, but again no data.

Then the video loses v-lock (image rolls) and has got to the point where its now unusable. The really frustrating part is that when the hex is on my workbench (powered up as if ready to fly), the video complete with data is there, rock solid. It's only when I get the copter outside that the problems begin.

So far, I've tried all the different tx/rx channels available and have replaced the Zenmuse HDMI cable and the HDMI convertor to no avail, I've even tried a different AVL58 TX and an iftron TX/RX that I have on another copter so I think I can rule out the downlink being the issue.... I'm starting to think I may have a dodgy iosd but as you can understand, I want to get an idea if anyone else has had this problem before I get the chequebook out again!

Much appreciate any info at all you can give.

1st image is when the iosd is set to input 2 (no video input), 2nd image is when the iosd is set to input 1 (the input the camera is going into). As mentioned doing the same procedure when the copter is on my desk, the data is superimposed over the video and locks absolutely fine.



View attachment 15572View attachment 15573

 

[Tahoe Ed]

I would try another iOSD. That is not normal and you have spent a lot more money than would have been required to just replace the iOSD. If you do not need the data logging, try a iOSD mini. They are inexpensive. I have the mini, MK I and MK II. I fried the MK II's power output but it still works.

 

[AirCamPro]

We have has something like that happening to us and found it was a poor contact to the Antenna. Also if you can try bypassing the iOSD and have the AVL58 TX connected straight to your video source to rule out the TX of the iOSD first.

 

[Cheshirecat]

+1 on AircamPro comment, my TX antenna actually fell off in the workshop, they are not so well crimped on. I thought I had put it back on properly but whilst pre flight on the bench I could not get any feed from my NEX7 only IOSD and that was poor jagged. Following some wiggling I got weak grainy video from the camera. So a better executed re crimp and bingo back in the game. I will get a spare TX antenna now.

 

[nickedw]

+1 again, there is a design flaw with AVL58 IMHO, the aerial connector is just clamped by the case and soldered, it isn't mechanically held in place with a nut, so as you flex the aerial, the solder joint fails and lifts the track on the PCB like this

View attachment 15812

The upshot being that it works on the ground and it's only when you get some vibration from the motors that the video feed degrades. I have now run a s small wire from the centre pin of the aerial connector to PCB to allow some flex on all my units.

Regards

Nick

yonda aerial systems