Low RSSI

[dadboldt]

I've had a Taranis X9D for several years and have 8 planes I fly regularly with it and have never had any problem with the system. Recently I built a new plane (20cc gas Phoenix Edge 540) and experienced a problem I had not seen before. During bench tests I was getting intermittent loss of communication between the transmitter and receiver. I changed the new receiver (X8R) with another new receiver (X6R) and had the same issues. I changed batteries, antenna positions, etc and could not resolve the issue. So I set the plane aside and instead built a new electric foam Skipper using the new X6R receiver. I didn't expect a problem but on it's maiden flight I got a low RSSI warning right at liftoff and critical RSSI warning as I banked back to the runway. That happened right after a long trouble free flight of my Something Extra using the same transmitter. I also did a range test with a friend's Taranis bound to the Skipper which gave critical RSSI results as well. Those two facts caused me to rule out a transmitter issue in my mind. I then took a proven receiver (X8R) out of one of my older planes and put it in the gas Edge 540 mounted just as the prior receiver and got great RSSI results on a range test.

My analysis leads me to think I have two bad new receivers, as crazy as that may seem. Or perhaps the antennas on the receivers (flat PCB on the X8R, whisker on the X6R) are not performing as well as the plastic ends on the older receivers. My question is whether anyone has experienced similar problems?

 

[AussieBob]

I am having some similar problems atm, all models worked well 12 months ago, but now no range. I have 2 TX's Taranis and plus and have used both with same result. I have been flying 20 years, so no setup issue (i hope).

 

[flyandride]

I've had similar problems with short range on certain receivers with pcb antennas. In each case it was sloppy soldering on the pcb antennas which shorted the inner wire of the coax to the shield where it was soldered to the antenna board. In another case, there was no continuity through the coax to the antenna board due to a break in the inner conductor.
What I do now is check all pcb antennas for continuity from the ipex connector to the board and that the inner conductor is not shorted to ground.
I got one X4RSB receiver that just had really poor range, as in a couple hundred yards even with good antennas.

 

[BigChinoDon]

Or perhaps the antennas on the receivers (flat PCB on the X8R, whisker on the X6R) are not performing as well as the plastic ends on the older receivers.

Take the plastic covers off an older receiver and you'll find the same PCBs inside. As I understand it, FrSky removed the protective covers to save weight. Should not effect range.

Have you updated the firmware on the receivers?

 

[Wayne]

Firmware upgrades will not change range performance.

Does your 20cc gasser have ignition? If so, please check the condition of the spark plug, they are very good at making noise on the 2.4 band.

Is it possible to have 2 bad receivers? Sure, anything is possible. I will suggest doing a quick test of just the receiver and a battery, nothing else. No servos, no airplane. Same results? If so, bad receiver. If not, something else is at issue.

Hope this helps!

 

[dadboldt]

Firmware upgrades will not change range performance.

Does your 20cc gasser have ignition? If so, please check the condition of the spark plug, they are very good at making noise on the 2.4 band.

Is it possible to have 2 bad receivers? Sure, anything is possible. I will suggest doing a quick test of just the receiver and a battery, nothing else. No servos, no airplane. Same results? If so, bad receiver. If not, something else is at issue.

Hope this helps!

Thanks for this forum and your reply. Yes, my gas engine has an ignition and I also thought that might be the problem but the problem persisted on the bench with the ignition turned off. I swapped out the receiver battery, moved the receiver and tried several other remedies without success. Finally I replaced the receiver with a known good one with everything else the same and got great RSSI readings. I hope to fly it this weekend. This afternoon I replace the receiver (whisker antenna's) on my Skipper with a new identical receiver and it also has great RSSI readings now. This leads me to look further into the two receivers. I'll let you know the results of your suggested test with just batteries. I'm also going to open up the receivers and test for proper soldering and continuity on the antennas as suggested in the other response.

 

[dadboldt]

Take the plastic covers off an older receiver and you'll find the same PCBs inside. As I understand it, FrSky removed the protective covers to save weight. Should not effect range.

Have you updated the firmware on the receivers?

Hi. Thanks for your comment. I have one of the early Taranis transmitters and, rather than updating the software on it myself, I sent it back to Aloft last summer and they did the updating on it for me. Unless there has been more updates since, I should have the latest. Thanks again.

 

[Wayne]

Hmm, sure sounds like you have some bum receivers. If you bought them from using the last year, they are covered under our warranty. Send them back with a note. (Or a print out of this page..)