Minimum distance between inductor beads and an RF transceiver?

I there a minimum distance needed between the beads and the RF transceiver?

Like below ... the connections do not really matter, just if there are requirements regarding the distance between the bead and a nRF24L01 transceiver?

Through the bead MIDI data is send/received (31250 bps). I draw only 1 bead, there will be 18.

simulate this circuit – Schematic created using CircuitLab

• @kva: I updated it with the circuit (official circuit, looks like mine). However, the beads are in between the MIDI connector and the microcontroller (so inside the box). – Michel Keijzers Jun 29 '17 at 11:07
• If it isn't exactly your circuit then it tells nothing. Post your circuit and not some impressionist version. – Andy aka Jun 29 '17 at 11:24
• @Andy aka ... I think it's not even related to the circuit ... it's more related if the distance between the transceiver and the beads are important, or do the beads only affect the cables through it? Not the receiver (antenna) which might be an inch (or more or less). – Michel Keijzers Jun 29 '17 at 11:48
• Coupling is proportional to TWO key factors: rate-of-change and area. Your MIDI data is slow, with "slow" edges. And your area (of the victim or receiver of energy) should be very small, what with GND planes under the various radio PCB traces. Assume 100nS edges on MIDI data, charging 100pF over 5v. The current is 5mA. We'll assume the rise time is 50nS. Assume your loop area (in the radio) is 1mm by 1mm, at distance of 10mm. The induced voltage is 2e-7 * Area/Distance * dI/dT = 2e-7 * 1e-4 (A/D) * 10^5Amp/sec = 2 microvolts, at the MIDI data rate. – analogsystemsrf Jun 29 '17 at 15:25
• The 2uV was the magnetically-induced voltage, at the MIDI bitrate, into your radio. – analogsystemsrf Jun 29 '17 at 16:59