If you are getting bad range or unexplained failsafe from your Jumper T16 or Radiomaster TX16S when flying with the multi-protocol module, the problem could be fixed by frequency fine tuning. Here I will show you how to fine tune frequency setting in the radio.
Go to “Model Setup”, scroll down to “Internal RF”, you should find the option “RF Freq. Fine Tune”. Default is 0, and you can change it between -50 and 50.
Do I Need Frequency Fine Tune?
If you see this “Fine Tune” option, you should do it regardless for optimal range. If you don’t see this option, it means the protocol you are using does not require frequency fine tune.
Protocol that requires fine tuning are:
- Frsky D (e.g. Frsky D4R, D8R)
- Frsky X (e.g. Frsky X4R, XSR, XM+)
- Frsky V (e.g. Frsky V8R4, V8FR)
- S-FHSS (Futaba S-FHSS)
- Corona
- Hitec
- HoTT
- Any other protocols that uses CC2500 RF Chip to emulate XN297
Steps to Fine Tune Frequency
Place your quad a couple of meters away from your radio.
You will need to adjust “RF Freq. Fine Tune“, and it will have an impact on “RSSI: x dB” next to it, which is a signal strength indicator.
Increase “RF Freq. Fine Tune” until RSSI drops to 0 dB. Write down that number.
Now decrease “RF Freq. Fine Tune“, signal will come back, but if you keep going, you will get another RSSI drop. Again, write down this number.
The middle of these two numbers is what you want to set “RF Freq. Fine Tune” to. How to work it out? Simply add the two numbers together and divide by two.
For example, if I had 24 and -48, it would be (24-48)/2 = -12
Why this is needed?
I think it’s just the downside of having multiple protocols. Jumper explains why this is required:
Original FrSky, Futaba, Corona Hitec, and HoTT receivers have been frequency-tuned by the manufacturer at the factory. Because of variations in the oscillator crystals used in multiprotocol modules, it is necessary to fine-tune the module to match the manufacturer frequencies.
‘Compatible’ receivers suffer the same variation in crystal oscillators as multiprotocol modules but have to be compatible with genuine (manufacturer-tuned) transmitters so they will typically have auto-tuning built-in, and will self-tune to the radio’s frequency when they are bound.
25 comments
If this the same method if I’m using a external plug in module? Trying get my futaba R2006GS receivers to work.
I don’t have experience with Futaba radios, this guide is for radios that’s running OpenTX and EdgeTX such as TX16S and T16.
Hi, thank you for your article. In my case, RSSI value is always 0, binding to my helicopters eachine e150 and Omphobby M2 using the Futaba SFHSS protocol. Is there any other requirements or settings to check the real signal strength? Thank you. (Radiomaster with EdgeTX 2.8).
Hi,
My Jumper T16 radio w/ internal module gets no signal at any adjustmet on positive values. It starts to get signal at about -80 (UPPER LIMIT) and It goes down to -127 . However I cant go below -127 to get the signal lost and determine the LOWER LIMIT.
Should I worry being so distant from Zero?
Also if I could not determine LOWER LIMIT, which MIDDLE POINT should I consider?
Thanks in advance for any advice.
Hi. I’m using two FrSky R-XSR receivers in a redundant setup. I’ve tuned the master Rx. How do I tune the slave since it is on the same Receiver ID/No.? Thanks in advance.
What if the receiver doesn’t have telemetry? If it’s just a small parkflier airplane
thx oscar for the info , is very helpfull , the force be with you
Sir, I could not bind to V761 where gyro is working but when I move the stick, the ele, ail and rud did not give any response. I can only bind if I tick low power mode. I tried to fly the plane but it lost signal after a few meters. Is the transmitter defected?
The V761 protocol on the 400mm planes will only work in low power mode as you found out. This is deliberate to reduce the power to low vales where there is no restriction on transmitters similarly to garage door openers, and light switches. Full power would require the transmission to be certified to local regulations and control.
Sir,
I don’t see any “RF Freq. Fine Tune” option in my Models Setup Menu.
If you don’t see that option, means you don’t need to worry about it.
Hola tengo un r_xsr y mi drone no arma,va y viene la telemetria,lo he afinado y me da un valor de 44 y ya si arma es normal un valor tan alto
Gracias de antemano
Hola acabo de afinar mi r_xsr por no arma y me da 44 al afinarlo
Es valor es normal?
Por que veo que a otros le da en negativo o poco en positivo
Gracias
Good article Oscar. Which rx protocols DONT require tuning?
It is a pita having to do this for every rx I have…..
No, just do tune it once for each TX protocol you are using, and it should work for all RX for that protocol. You are tuning the transmitter module, not the receiver.
Oscar, I disagree with you there as just checked the tuning between two models using different makes of receivers, ones a Futaba, the other FrSky. The Futaba fine tune is 46, the FrSky is 23….
Hey Oscar, I’d like to thank you so very much for putting out all these fantastic tutorials with including the examples that you did. I’m very new to fpv and have been looking everywhere and watching so many YouTube videos that I think I went overboard and got myself so confused on what to do first, and how to do it correctly. I was ready to pack it all in and just sell everything I’ve bought so far. I’m so glad I tried one more time and found your website, it’s exactly what I needed to put myself on the correct path again. Your explanations are I think the best and easiest to understand. Thanks again, I’ll definitely look you up on Patreon and check out your videos. All the best to you. Mike H.
Hello, I have the Radiomaster and 3 Flysky recievers… the option dosent enable… Do you have any idea?
Hi Oscar, I understand ther is a config file which can be written to force the fine tune into certain offsets. Now this would handy if the module was used in different transmitters. I have been reading this on github, but there aren’t any examples on how this done in plan English(a copy of the config.h file and where to place it),any help would be appreciated
Assuming you should do this for fixed wing as well.
So this value is different for every mutliprotocol module and different for every module and receiver combination, where the receiver is from a different manufacturer? Or does it vary based on the protocol too? (D8, D16, FCC vs. LBT)
I think this is important to add because I tuned mine for FrSky D16, but then got really dangerous corrupted packets on a jumper receiver that caused the quad to go into a deathroll without signal loss. Since I retuned for the Jumper RX it was fine.
You can read it from the RSSI value in Betaflight or from the OSD. The XM+ can be flashed with firmware that outputs RSSI always on channel 8 or channel 16, that’s what the firmware labeled RSSI is for. I believe there is also an RSSI pad you can solder to.
Hello, for method 1 how much is best to put the quad far from the ground and from the transmitter? Thank you Oscar for all your work!
a few meters should be fine
How does this work if I’m using xm+ receiver without telemetry