Receiver help Needed
Futaba will replace the filter regardless if they can determine it has or has not contributed to a problem. They do so, every time an RX is serviced... Furthermore if the filter is cracked, how does one discern if it's not a casualty of the crash? What other items were eliminated as problematic?
I have been told by a well known and respected published RC Tech guru that Hitec's Supreme 8 PPM/FM RX's score much better than other OEM units in his rigorous test and evaluation scheme... BUT the "other's" that score lower seem to work fine in field use. What does this mean??? It means some reject noise better than others, some develop noise internally more than others, all the while they all seem to get the job done most of the time and there's more.
These test scores are evaluated in like groups of RX's as well. This means that OEM #1 one may have a higher scoring unit with his 4-channel RX than OEM #2 with his 4-channel RX and or vise versa as we progress through the various OEM's product lines.
My personal preference is for PCM in my GS models. What many do not associate with regard to a comparison is that PCM equipment is able to score nearly 20 point higher SNR (signal to noise ratio) compared directly to PPM before it is affected by the same level of noise that starts to render PPM unstable.
FM/PPM is analog, the pulse positions can be shifted by RF noise after the signal has been transmitted to the RX (RF noise typically causes the wave to change in amplitude and width, herein lies the problem). This is known or realized as interference, servo dither, glitching and or NO control of the model.
FM/PCM is digital, PCM pulses don't have to in perfect wave form, they can change in amplitude, width or both. The decoder is only looking for the presence of pulses, either they exist or they do not. If you miss a pulse train the RX doesn't get excited, either!
Hitec's Digital servos offer a true programmable failsafe feature without the need for a special RX (PCM / IPD) and work with any system to the best of my knoweldge.
That's my nickle's worth....