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BrianG · 04.17.2009, 12:14 AM

Any radio signal can get washed out with enough noise. And frequency harmonics play a role too, so even if the noise if way under the radio freq, the harmonics may be such that it falls right in that range after all.

From testing various BECs, it seems you get what you pay for. The best performers for low/no noise are Koolflight, DimensionEngineering, and Western Robotics. Even so, I try to incorporate some type of shield, which is usually just a piece of aluminum between the receiver and UBEC. That way, more noise is reflected away from the sensitive circuits.

If you must run low-level signal wires near high current wires, it's best to have them meet at 90* angles. The way electromagnetic flux works, it is more difficult to induce noise into the other wire. This is the principle behind braiding the motor wires.

It depends on where the noise is coming from too. If it's the antenna, only moving it further away from the high current wires, or using a different radio will work. If it's the throttle line, there are still two possibilities:

1) noise entering the 6v power wire. This could be from a noisy BEC or induced from nearby high current wires. Adding a capacitor to the 6v power line can help, as can wrapping the servo wire around a ferrite ring a turn or two.

2) noise entering the signal wire of the throttle cable. This affects the signal the ESC and servo sees, so may cause erratic behaviour. A cap won't help here, but a ferrite ring should work.

	(#13)
BrianG RC-Monster Admin Offline Posts: 14,609 Join Date: Nov 2005 Location: Des Moines, IA	04.17.2009, 12:14 AM Any radio signal can get washed out with enough noise. And frequency harmonics play a role too, so even if the noise if way under the radio freq, the harmonics may be such that it falls right in that range after all. From testing various BECs, it seems you get what you pay for. The best performers for low/no noise are Koolflight, DimensionEngineering, and Western Robotics. Even so, I try to incorporate some type of shield, which is usually just a piece of aluminum between the receiver and UBEC. That way, more noise is reflected away from the sensitive circuits. If you must run low-level signal wires near high current wires, it's best to have them meet at 90* angles. The way electromagnetic flux works, it is more difficult to induce noise into the other wire. This is the principle behind braiding the motor wires. It depends on where the noise is coming from too. If it's the antenna, only moving it further away from the high current wires, or using a different radio will work. If it's the throttle line, there are still two possibilities: 1) noise entering the 6v power wire. This could be from a noisy BEC or induced from nearby high current wires. Adding a capacitor to the 6v power line can help, as can wrapping the servo wire around a ferrite ring a turn or two. 2) noise entering the signal wire of the throttle cable. This affects the signal the ESC and servo sees, so may cause erratic behaviour. A cap won't help here, but a ferrite ring should work.