Ferrite Rings

[David Davis]

I am planning to fit the elevatoer and rudder servos in the rear of my Barn Door Telemaster. With an FM system the convention was to fit ferrite rings in the servo lead extensions.

 

Is this necessary with a 2.4 Ghz receiver.

[Tim Mackey]

No

[Lee Smalley]

its only necessary if you have glitches or interference it does not matter if its 2.4 gig 35meg or 2347646785 mghz   i do rf and emc testing at work and it does not matter what frequency you are on rf and emc interference can effect anything wether it be emmission or susceptability

i will not bore you to tears but "Noise" which is the generic term for the above can couple onto the long wires and travel up them and effect components in our rxs and our servos, thankfully it is quite rare in our country as we have stringent controls on the equipment we use and the frequencies we broadcast on, it does not matter on what system you use it depends on the equipment quality you are using and the area in which you fly

2.4 gig does not make you immune to this it just makes you less likely to have in air clashes with noise as general noise is well below this frequency

 

wake up those who fell asleep at the back !!!!!

[Brian Parker]

I’m with Timbo,
 Simplified, 2.4Ghz Spread Spectrum operates ‘in the noise’ via ‘Pseudo Noise’ codes and is thus immune to RF pickup via the servo leads.

[Tim Mackey]

I think Lee is coming from the " interference can travel directly to the servos via the leads" and affect them, rather than the Rx.

 

Must say, never known of that m'self, and in my 35Meg days, always followed the rule of fitting the ferrite ring as close to the rx input as possisble, cos thats where the interference was expected to be, so fitting them there would "trap" any such gremlin just before it entered the rx.

Still, no harm in fitting them at the servo end as well I guess, but as to their effectiveness, I never found them much use TBH.

All 2.4 these days, and having never experienced any glitching whatsoever, even woith 3 foot long sevo leads in some models, gave away all my ferrites to clubmates yonks ago.

[Lee Smalley]

this is not about 2.4 gig or where it operates in the frequency range rf noise can couple on to any wires and travel up them to effect the components inside the rx or indeed servos etc as i said this is very rare as we have very good controls not only on rf splattering equipment but also the equipment that is made for use in this country ie its susceptibility, trust me i operate ananechoic chamber which we test our products one of which is a 2.4 gig dongle (wireless comms port) and trust me that's been susceptible to frequency's far less than 2.4 gig!!!     due to poor design !!!! whoops 

 

as i said its very rare and i have only once found a ferrite ring to be of any use on our radios