Taranis X9D Plus losing signal

[Sacalu]

Hi, I need some advice please because I have a problem with my Taranis X9D Plus EU version and X8Rs EU version. Right after I enter range mode, in one out of 1 to 5 times the signal is lost no mather which of the 4 rx I use. I've noticed that if the RSSI starts at higher than usual, 91 or so than most likely will drop to zero along with telemetry lost alert and lost of control, if it starts at about 77 RSSI it usualy keeps the link. The control is regained by: aproaching the rx at 2-6m (which sugests a very weak signal in range mode) or exit range mode, or reboot the rx or the tx. This happens with all my four X8Rx, and only in range mode. But once it happened during flight when I heard telemetry lost. Well heaving 2 rx onboard I never felt a signal loss so I landed the plane safely.
The rxs have their antenas at 90 degree, and were tested at over one meter from the ground on a wooden tripod. When activating range mode if the signal isn't lost in the first 3 sec it will last and I get 50 RSSI at 100m which is good. With an orange module atached on the back I get 30m on the orange rxs with no problems.The sistem has over an year. I didn't rush to firmware as I've read that many that did, got other problems after that. The Tx antena seems to be well soldered. Any thoughts please? Thank you.

A video in the house with the exact thing that happens at the field, just that in the house because of limited space I had to keep the tip or botom of the Tx antena towards the rx to lose signal, which is not the case at the field.

 

[HENNY]

Range check should be completed out doors in an open area with you model at least 1 meter above ground. Out doors you should expect at least 30 meters or more while in range check mode. At our flying field I can easily achieve 60 meters before the RSSI reduces to 45db. One thing to remember is your body can act as an RF shield, so if you are walking away from your model the RSSI will drop off faster then if you are facing your model, IE walking backwards. If you can only achieve a few meters out doors in an open area I would try replacing your transmitter antenna and if that fails the internal XJT module may need replacing.
Henny

 

[Sacalu]

The tests, beside the video, were at over one meter from the ground on a wooden tripod. I've never walked away with my body between the Tx and Rx Always walking backwards, side of tx antena towards the Rx, I get not 45 but 60 RSSI at 60m and 50 RSSI at 100m, and 0 RSSI at above 200m! All of these when the signal is not lost. But one out of 1 to 5 range test end up with RSSI droping to 0 right at the begining of range test, no mather the distance, antenas at 90, higher than 1m above ground, good accus etc. Thanks, besides XJT module, you're the first to consider antena replacement, thank you for that point, I didn't consider... I've moved the antena wire with a tooth pick, during range mode, the signal didn't drop..it's hard to believe that is a bad conection if the signal drops when the Tx "feels" so...like you enter range test and the signal is ok , 50 RSSI at 100m, you enter again at let's say 5, 15, 20, 40 m doesn't matter, it drops to zero, no signal. Then you exit range test, signal back on, enter range again maybe 6 times and doesn't drop...that's how it is.

 

[Wayne]

Watching your video - I see the RSSI at 0 but you still have control of one elevator servo. How is that happening? If the RSSI was at 0 you should have no connection with the aircraft, but I see you have 2 receivers in this setup. I assume you have some sort of power box wrapped up in the foam.

I think your main receiver that has telemetry reporting is going to 0 RSSI, but your second receiver then kicks in, but it can not report telemetry as the Taranis can only receive one telemetry stream at this time. But here is the interesting thing. Your power box solution is not getting all of the channels from your backup receiver, thus you have a single elevator still working.

Best guess is you may have a 2 issues going on. You may have a bad receiver, but I also don't think your power box is doing its job correctly. Or, are the receivers not in redundancy, and the second one is just doing channels 9-16? That is possible also.

Anyhow, it would appear to be an issue with the receiver that has the telemetry on. You can test this by binding the 2 receivers to different model memories and switching between the 2 receivers and see what is going on. This will alternate control to the different receivers.

As to why this only happens from time to time, hard to say. If you have a power box that is using just one receiver at a time, then the answer may be that it depends on what receiver the powerbox is listening to, and it has some programming that needs to be cleaned up.

In the end I suspect one of the receivers is bum, and possibly some other issues. Keep testing and you should be able to find the issue.

Any reason you are not feeding Sbus to the power box? That would be a better method.