Transmitter Latency across brands

[Hydrocarbon92]

A while back I found a video testing some TX's usually used for planes, then started digging further.


The gist of the first link is the Flysky i6X had the best latency among , averaging 13.5ms vs Spektrum's 50ms.

The next link shows some tests with a Futaba 4PK with various RX's and they ranged from 5ms to 15ms average, while the Sanwa M12 averaged 4ms. It also shows differences between various protocols - for instance their FAAST isn't appropriately named, as it's slower than their TFhss protocol.

The third link shows the "normal" Futabas & others averaging in the 10-50ms range.

Now to put this in context, your typical ultra-fast 0.08sec servo does a full 90 degree twist lock-to-lock in 120ms. Adding latency we get 170ms for Spectrum, 133.5ms for Flysky, and 124ms for Sanwa. Another thing is a high-end servo is running on a ~300hz refresh rate, so you add another 3.3ms for RX "output lag". To help put this into context, a high-end gaming monitor at 144hz will have 7ms between frames and 16.6ms for a 60hz gaming console; a movie is 42ms between frames. The fastest human reaction times are ~166ms.



When I do some maths for how that lag affects your servo, it gets interesting. A typical $400+ radio is less than 8% faster than a $50 radio, less than 10ms. Money well spent I see...

FrSky/Flysky/Spektrum:
https://www.youtube.com/watch?v=75E1WSrwqaY&t=420s

Ultra-fast Futaba/Sanwa tests:
https://www.rctech.net/forum/radio-e...a-4px-152.html

Multiple TX test:
https://rc.runryder.com/helicopter/t172571p1/


PS: I know there are other benefits that $400 radio owners get for the price tag, but I'll pass.