Two jumpers, different behaviors.

I've got 2 Jumper T8SG V2 Plus controllers (grandson and I fly together) that should basically be twins except the colors of the cases. Lemon-RX had a sale on Stabilizer Plus receivers so I bought several. They all work fine with the 'carbon' controller but all have continuous small and occasional lengthy dropouts with the 'yellow' controller. The yellow controller works fine with some other receivers, including older Lemon-RX receivers.

All transmitter and model settings are the same as far as I can tell. The carbon controller is on deviation-t8sg_v2_plus-v5.0.0-abc5dcf firmware which I have not been able to find online, and is not in its file system (?).

The yellow controller was on deviation-t8sg_v2_plus-v5.0.0-28ce50f. Since, I changed to -e801244 but the dropouts remain.

Of course there could be a hardware issue with the yellow controller, but with it working solid with other receivers, I would like to verify it's not due to timing or something in the firmware.

I've googled without success. Where can I find the deviation-t8sg_v2_plus-v5.0.0-abc5dcf build which is working fine in my carbon controller? Is there a way to download it from the controller itself?

Thank you vlad. Yes, I thought that was going to be "it". But I had tried OrangeRX and HighSpeed, One, the other, and both On. None of those worked.

I'm leaning toward my Yellow controller having a hardware problem, but want to try the deviation-t8sg_v2_plus-v5.0.0-abc5dcf firmware, which is working in my Carbon controller, to eliminate that variable. I haven't been able to find that firmware version though.

Also, I received this from a Lemon-RX engineer:

"I believe it's the Jumper's transmitter problem. Our receivers are primary designed to work with high accuracy frequency stable transmitter (+/- 10ppm or less expected or ± 25 ppm absolute maximum limit).
You should use Spekturm transmitter. I am 99.9% sure the problem will go away with a Spektrum transmitter.
We did take apart of a Jumper transmitter long ago and I can confirm you that the frequency cannot be guaranteed with ± 25ppm accuracy due to the use of parts."

Vlad, I cannot thank you enough. You have saved me days, if not weeks, of frustration trying to get this transmitter replaced or buying a new one.

I did as you said. First time clicked down to where the connection led on the receiver went completely out, and up as well. Split the difference to come up with -127. Tried again just for verification going only down until the first blink, and up until the first blink. Guess what? Same number, -127. The yellow T8SG Plus is now stable with all my Lemon-RX Stabilizer Plus receivers.

You might consider adding the Freq-Fine DSM2/X feature to all the Jumper builds in case other transmitters experience frequency drifts.

Again Thank you very much!!