Is it possible to cover APM with aluminum foil to minimize UHF noise interference?

Is it possible to cover APM with aluminum foil to minimize UHF noise interference or is it bad idea because of its sensors, please?

I use Mini APM 2.7.2.


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Stop ripping that F16 apart and check your email, your desk is looking far too tidy :-)
Hi Ben, firstly may I apologise for replying out of sequence to your latest post- for some reason I cannot reply under it. There seems to be some confusion in to exactly what we are all discussing which is leading to problems. Pavel has not to my knowledge ever claimed that the apm is causing issues to the majority, this is only a discussion over one particular scenario. If this is understood and the basic electronic and rf theory is applied we can see that the idea has scientific basis and merits discussion, more so we can also see that he is actually testing it in the only real way possible.
His distinct point of contention is that when using a UHF signal at its weakest strength, it looses performance due to background noise from other electrical components that includes the apm. I can see from your post that you accept that the apm generates noise as I have previously explained (at a very low level and without much distance). If we apply a suitable analogy, let's say trying to listen to a conversation far away that is approaching the limit of your hearing range. It does not take much noise close to you to render that conversation inaudible. Therefore, any noise that is generated will raise the noise floor and potentially affect the signal capability. Now as for how to test this supposition, it is standard practice to start looking for signals on particular frequencies but this is only part of it. Measuring the noise floor is almost impossible, as Alasdair had alluded- in order to measure you have to set a starting point. This is not as easy as you may think. Then you have to factor in as I have already pointed out, that the amount and type of noise generated is partly controlled by the processing and workload of the systems which changes all the time whilst in flight. Don't even begin to take into account sunspot activity etc.! Therefore one of the best ways to investigate is to shield various components and see if anything improves......
When you take all this into account you begin to see that Pavel is far from any of those things you called him. We are not discussing particular signals being generated by the apm on the UHF range, this is all about the general noise floor when operating at the limits and if shielding may help.

Pavels approach is terrible because he has measured interference from a set of things, guessed at the culprit (picking the wrong one) and then done no further test to confirm his guess.

On top of that when people have pointed him at the right ones to fix he has insulted those people and denied their knowledge, putting unconfirmed guesswork ahead of evidence.

Spot on regarding RFI EMI interference and abatement methods.

The hobby industry in has not been using what are generally known methods to minimize these issue.  

Runcam recently made a camera where they applied a copper flash tot  inside of the case and effectively minimized spurious RF that was causing issues with some 433 systems. This is a common practice with many consumer electronics products and is relatively low cost.

In my opinion it would be good practice for more companies to follow and implement such methods. As mentioned every circuit board trace etc can act as a antennae radiating or receiving whatever radiation is present.  In close proximity even relatively weak emission can be an issue.  As mentioned RF is a bag of worms and interconnect wires, filtering methods etc can have a major impact on performance.  But the hobby industry in general is very lag on even minimal and common methods of control and needs to improve in this area.  More electronics are being put on craft including Video transmitters, Data modems, receiver telemetry, flight controllers and this is creating a complicated RF dense environment where interference can impact overall performance and reliability.

I have had to implement shielding on some APM installations where components were close together and the effects of RFI could be clearly seen.  GPS units in particular can also be very sensitive to the radiation emitted by electronics.

I'm not sure it is to minimize model life so much as not keeping up with changes that are going on.

Used to be just a receiver and speed controller and maybe a BEC were on a craft.  Now there are many components closely spaced.  Microprocessors, video processors, multiple RF transceivers, multiple ESCs etc creating an environment much more prone to interference impacts.  The cheap unsheilded electronics and cables and minimal filtering of spurious radiation are just not sufficient. 

I built a micro-copter 200 class with a Mini APM.  Due to the close proximity of the GPS and Mini APM the performance of the GPS was dramatically affected.  As the GPS got closer to the APM the performance dramatically decreased. By putting shielding in place I was able to get good performance out of the GPS without moving it a great distance away.   On a larger copter where the spacing is greater this would not have been a issue but in close proximity it is.  But if the APM had some minimal shielding it may have not been a issue in the first place


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