Crash90

My Feedback: (17)

Need I be concerned with interference from the ignition on a gas engine if I am using a pcm receiver.

My Rxs' , battery, throttle servo, and choke servo will be around 5 inches from ignition for balancing. Thanks

Lynx

You always need to be a little worried about your electronics around a gas engine. It won't show up as much on a PCM receiver but that doesn't mean it's not occuring. Your best bet is to test with a PPM receiver to make sure nothing 'obvious' is going wrong and then use the PCM system after you've worked out any possible bugs. A constant low level interference might not show up on a PCM receiver untill it happens in flight, even if you range check.

JohnW

My Feedback: (6)

Regardless of RX type (PPM/PCM) you always need to be concerned with interference. 5" is a bit close IMO, but it may work out just fine. Ground check with engine running at different speeds. Compare that distance to a check with the engine totally off. If the distances differ by more than 20%, you probably need to adjust the placement of items. Engine off range should be at least 100 feet. Remember, with PCM you must either constantly move surfaces during range checks to detect interference; and/or, set failsafe to something like full rudder throw so you know when the RX entered failsafe.

The PPM check might clue you into major issues, but I'm not sure it really serves a practical purpose. It won't hurt anything to do that, but just because the PPM RX doesn't get interference doesn't mean the PCM won't either. You really need to test the RX you plan to use as each RX (even two identical models) can have their own unique issues. With the above mentioned test, you will "detect" low level interference. It will show up as reduced range with engine on vs engine off.