Hello Pilots,

I've got a iFlight F7 mini stack installed on a Aluminum Babyhawk R frame. Using both SBUS and F.Port protocols all seems good. Able to bind to the FrSky (R-XSR) and hover.

However, FPV video is lost (both protocols) when my Taranis X9D binds with my R-XSR (looks like no VTX attached). If I turn off the Taranis X9D, video returns.

What??? How does that happen?

Has anyone experienced this problem?  

Please enlighten me.

Thanks George

Hi George,

Is there any chance you're using smartaudio or tramp telemetry with your VTX? It could be the case that in "modes" under betaflight you have a radio command mapped to set VTX to pit mode. Other than this there could be a conflict between ports but this is unlikely.

If you could provide more details about how it's wired up (what to which UARTS etc) and which components are installed (VTX and CAM) this would be very helpful.

When you lose video does it go black screen, black with OSD, or snow?


I also find it interesting you talk about both S.Bus and F.Port. You use S.Bus and S.Port together, but F.Port is a different protocol that combines both S.Bus and S.Port into the one wire and only utilises one uart. See the blog post here: https://oscarliang.com/setup-frsky-fport/

Edit: Just looked, you can get a version of the stack with included VTX, if this is what you have it very well could be an incorrectly set parameter in "modes" as I suggested at first.

Hello dude, Thanks for your response!

No, sorry for the confusion. I tried using both S.bus and F.port separately (on UART 4) with the same results.
I'm using Tramp telemetry with my VTX.

No Modes are set to "Pit Mode"

When I bind the Taranis with the receiver i lose video and it goes to snow, when I turn off the Taranis i get clean video again.

Not sure how to attach a picture on this forum, however I have it wired according to this link https://www.iflight-rc.com/index.php?rou...uct_id=912 You can find the wiring diagram (Succex mini F7 V3.0 Twig Manual) for sbus and f.port wiring on this link. Used both with the same results.

this sounds like an electric circuit issue to me; if the receiver receive commands the ampdraw increase.
can you mesure the voltage of both, vtx and receiver (when you the taranis is conected and the video is lost) what voltage do you mesure on the vtx pads? how do you wire your vtx? to the 5v circuit? if it can handle the battery voltage, i would suggest use the lipoin pads to power the vtx.
the problem could be to much ampdraw from your fpv and radio gear, probably the vtx hasnt enough power after the 2,4ghz conection.

Telemetry receivers are known to cause video interference. I take it that your rx antennas and vtx antenna are in close proximity to each other?

If you have the receiver and vtx circuits close to each other this and contribute to the problem too.

Try separating the rx antennas from the area the vtx antenna is in. Ie: maybe move the rx up to the front of the quad and mount the rx antennas off the front arms.

Also if you can’t move the rx and vtx circuits away from each other then a grounding shield placed between them will help. This can be a piece of foil or similar metal that is connected to GND on the battery.

Hope this info helps and good luck!

ph2t.

(21-Nov-2019, 11:24 AM)ph2t Wrote: Telemetry receivers are known to cause video interference. I take it that your rx antennas and vtx antenna are in close proximity to each other?

If you have the receiver and vtx circuits close to each other this and contribute to the problem too.

Try separating the rx antennas from the area the vtx antenna is in. Ie: maybe move the rx up to the front of the quad and mount the rx antennas off the front arms.

Also if you can’t move the rx and vtx circuits away from each other then a grounding shield placed between them will help. This can be a piece of foil or similar metal that is connected to GND on the battery.

Hope this info helps and good luck!

ph2t.

Wow!

You're right about the antennas being in close proximity to each other. Separated the antennas by installing the receiver antennas in front and the video antenna to the rear. Worked like a charm!

Thanks ph2t, great response!

I'll have to install the Holybro mini stack I ordered to replace the iFlight stack on another frame.