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rf noise

PostPosted: Mon Jun 04, 2012 12:09 pm
by danmor2
Please i need some help in rf noise

hi to all
1 am new in this form
2 how do i reduce rf noise ?? can i cover in sam material the all noisy prodact
i keep receiving rth from 433 mhz system with all the filters
in my setup on the model there is
1 et system with Guardian Stabilization Expander
2 The TeleFlyOSD for myflydream aat
3 FOXTECH heavy duty 3A step-down regulator for 12v to the cam and to the video tx
4 Turnigy 5A (8-40v) SBEC for Lipo for the rx and servo and to the TeleFlyOSD
5 cam and video tx 1.2ghz


Re: rf noise

PostPosted: Mon Jun 04, 2012 10:46 pm
by RCModelReviews
Reducing RF noise can be a very tricky problem -- somewhat like nailing jelly to a tree.

Shielding is your first line of attack but to be effective, the shielding must be grounded (ie: to the negative lead). Simply wrapping something in a metal foil and not grounding the foil will often result in the signal being re-radiated by that foil.

Using ferrite toroids (rings) on all wires, as close as possible to the devices they connect to can also help.

However, low RF noise is a design issue and it can be rather difficult to compensate for a badly designed piece of electronics by attempting to add noise-reduction as an after-thought.

Maybe I should have a think about doing a video on RF noise - what it is, how it affects our systems and what can be done to reduce it.

Re: rf noise

PostPosted: Tue Jun 05, 2012 1:45 am
by Mark Hitchman
The first thing to do is find out which component/s are causing the interference. Put your 433mhz system in range test mode and turn on your various devices to see which ones are reducing your range check. Try the camera and VTX first, they can spew out a bit of rfi.

Separation is usually the answer, maybe a photo of your layout would help.


Re: rf noise

PostPosted: Tue Jun 05, 2012 10:44 am
by danmor2
Hi Bruce

you are my guru on rc and thnaks for yours thought :)

can i only cover all or individual and conect to any ground
on the receiver
i will put ferrite rings on all cables


mark thanks to
here is my setup ...

Re: rf noise

PostPosted: Wed Jun 06, 2012 1:24 am
by RCModelReviews
You're best focused on shielding those items that are more likely to be transmitting the RFI rather than the receiver (which has to receive radio signals to work anyway).

As Mark says -- do some trial and error to see what exactly it is that's emitting the noise.

A cheap hand-held FM radio can help here -- you'll hear the noise increase significantly as you move it closer to any part of the system that is radiating RF.

Re: rf noise

PostPosted: Wed Jun 06, 2012 9:11 am
by danmor2
thanks Bruce

i will do the fm redio test and let you know

this is the vid of the flight


Re: rf noise

PostPosted: Mon Jul 16, 2012 6:56 pm
by danmor2
OK mates

i discover the killer
it is a bad receiver
i return it to foxtechfpv
and Fu credit
thanks to Fu for the best serivc

and to you Bruce for cooperation
here is my new project

and thanks to all