ORIGINAL: dave-g4nju
I have tested several RX. At the point where you can see the servos twitch at low signals on a range check the servos are drawing a lot of current. This for PPM. I found that you had to increase the signal by 20dB to get each servo current below 20mA! With the PCM RX this does not happen they keep producing a clean servo pulse right down to the point where they drop out at about 2 microvolts. The best PPMs needed 35 microvolt to get the servo current down below 20 mA each!
I suspect that what you are seeing is the difference between failsafe and non-failsafe rather than a difference between PPM and PCM. Have you done the test with a Multiplex IPD PPM failsafe receiver or FMA DSR PPM failsafe receiver? I would like to see the numbers from them I suspect they will be very close to PCM.
H