Frsky problem.

[takilara]

I tried using a 12V PSU that i dropped to 11.3 V using a diode. Had same jitter issues. Exchanged the PSU with a 20C 3S LiPo battery. Same issue. Tried a small capacitor, and a large capacitor with no change. Noise on the powerline was much higher when using the PSU.

[JMP_blackfoot]

I read somewhere that someone got rid of the jitter by reversing the polarity of the PPM stream (positive to negative or the other way around)?

[takilara]

Hmm that could be tested. Can any of you electronic buffs say if there is any danger with this procedure? I don't have a breakoutboard, so i cannot test it beforehand...

[mr.sneezy]

Hmm that could be tested. Can any of you electronic buffs say if there is any danger with this procedure? I don't have a breakoutboard, so i cannot test it beforehand...

No danger. The FrSky modules all seem to be logic sensing, just like the hack modules. A friend grafted an old Two-Way Futaba board into his JR Turnigy radio just fine.
If I recall, can the Optic6 select logic sense in it's system menu ?
Otherwise we'd need an inverting buffer in between.

[mr.sneezy]

Mr sneezy,
I just tried a "Y" lead - no effect. The jerky servos are still jerky whether there is one or two in the port, and the smoother ones are still smooth. That is an exact "jerky" btw, not a guessed one
Tried a different rx supply, still the same. Might try a low esr cap on the tx module.

To clarify, did you mean you had a smooth servo and a jerky servo on the same Y-cable at the same time, and they both remain true to type ?
Or did you have two jerky servos, then try two smooth in two separate tests ?

[mvvs35]

I do not think that the polarity of the PPM problem. Neither the noise generated by the module in the supply line. Bruce and explain what the problem. And of firmware.

[RCModelReviews]

Just another data-point.

I finally had the chance to do a little flying on the weekend.

I pulled the standard servos out of my Mojo 40 profile 3D model and threw in the Savox digitals which gave me the jerkiest response on the bench.

After wringing the snot out of that model I can say that despite the +/- 50 degree throws on all surfaces, I really didn't notice any of the apparent jerkiness in flight. Even maneuvers like slow-rolls and large loops were smooth as silk.

I'm going to be talking further with FrSky to see why this apparent jerkiness of movement occurs. I have almost finished programming up the test rig (which I'll also be using later to test latency of modules/receivers).

[mr.sneezy]

After wringing the snot out of that model I can say that despite the +/- 50 degree throws on all surfaces, I really didn't notice any of the apparent jerkiness in flight. Even maneuvers like slow-rolls and large loops were smooth as silk.

Good to hear. I think we all can get a little carried away with the 'need' for ultra-high everything, just look at digital camera pixel creep. I was quite happy back at 6Mp !
While getting it silky smooth with fast servos is a very desirable thing, it's not the most important thing, and it will get sorted in time...
My 2 cents, and I just spent it.

[tommy]

Has anyone flown the frysky system with a heli. I think a heli will be more susceptible to jerky servos.
When I fly my heli on the frysky I think I can sometimes tell that the servos are a bit more jerky
than when I fly on 36MHz. It's hard to tell and I may just be a bit paranoid now.
I am interest to hear from other Heli flyers.

[mr.sneezy]

Has anyone flown the frysky system with a heli. I think a heli will be more susceptible to jerky servos.
When I fly my heli on the frysky I think I can sometimes tell that the servos are a bit more jerky
than when I fly on 36MHz. It's hard to tell and I may just be a bit paranoid now.
I am interest to hear from other Heli flyers.

Yes, I do. A Trex 500 clone, with all digital servos. It's my best flying heli. It has a V8 8Ch RX in it. I had Futaba PCM previously, and I won't be going back. So don't be too paranoid about it...
Actually I'm about to buy more FrSky receivers including another 8Ch for my other Heli.