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.
I would suggest it is a bad idea due to the very high chance of a short circuit.
The only sensor to be effected would be the magnetometer but if you calibrate it with the foil in place it should work.
I just taped it first with tape to protect it and then I covered with food aluminum foil, then again I tapped it with tape to protect aluminum foil and then I cut the holes to this three layers for connectors. Then I calibrated compass. It seems to work. Should I calibrate also accelerometer? Only I am afraid if it will work as normal?
Depends how you are fixing the APM to the aircraft. If it goes in exactly the same place each time (eg a mount) then no need to recalibrate the accel. If you use velcro, so not exactly the same place then you do.
I am not familiar with APM mini, but check that it isnt getting hot with all that tape and aluminium foil insulating it.
Is your APM actually radiating UHF?
I can think of more likely culprits for unwanted UHF 'noise', i.e. FPV camera, GoPro of similar.
Just move your Rx and antenna as far away as practical.
I just measured everything with UHF spectrum analyzer and used aluminum foil on power module, PlayUAV OSD and now on Mini APM 2.7.2. Going to measure differences. I try to move is as far as possible also. But would prefer to have UHF RC as much as reliable, that it is why I am doing this aluminum foil also.
You could also use a RX designed for a carbon fuse. We have RF challenges in high performance sailplanes thanks to the large amount of conductive carbon fiber in the airframe. Maybe you can also help abate some of the noise with a toroidal choke at one or more strategic locations?
This guy posted this question on Facebook too. He's oddly obsessed with wrapping things in tin foil and calling it "shielding". I've asked him repeatedly to show evidence of UHF emissions from the APM causing interference to RC. He's provided no evidence and makes excuses. Just strange assumptions. Also, the "UHF Spectrum Analyzer" isn't. He doesn't have a spectrum analyzer or any other actual test equipment. It's just the analyzer mode on the OpenLRS system. He posts a bunch of graphs showing UHF "interference" when he rams the antenna into the APM. But no evidence of any actual interference in flight.
I think anyone that actually uses the APM and UHF knows this is a total non-issue. Multiple people have tried to tell him this to no avail.
Where is he talking this up on FB Pedals?
Pedals2Paddles, you are totally crazy guy. I wonder how you can be such idiot and not expected behavior person. Hunting people over the internet instead of simply try to read, understand, ask, and study the facts. Please do that for me study things carefully. And do not hunt people!!! If you would study things you would know that in open LRS spectrum analyzer mode you can compare two signals. So to be able to measure noise. You do TWO measurements. First you Measure UHF signal when you have everything, all your FPV/UAV airplane/copter switched off with no battery connected. Then you click button "Safe Reference", and this signal will be marked in graph as Reference Signal with special orange like/yellow color. Then you do Second Measurement. You connect battery to your FPV/UAV airplane/copter and try to place step by step the electronic component which you would like to measure near the Open LRS spectrum analyzer antenna. If the signal gets above the marked "Reference Signal" it is clear that it is additional generated UHF signal/noise produced by that electronic component which is currently near or above Open LRS spectrum analyzer antenna. So this way you simply measure what produces and what does not produce UHF frequency band noise. Is it clear now? Please stop doing yourself an idiot and if it is not clear, just ask what is not clear, it is always better to ask than simply saying "no evidence", which is arrogant, ignorant and looks stupid. It just shows stupidity of person instead of trying to find out what other person tried to tell. Only one person which behaved that strange way was you!
Oh, did I mention his posts on FB were long and rambling too? All I did was ask if had inflight evidence that it's causing detrimental interference. He has no evidence of it, and as you can see, he just lobs rambling insults when asked.
For the good of the argument, do you have any evidence of in flight tests to prove that there is no UHF noise emitted by the hardware to support yourself?
Pedals2Paddles, I showed an example comparison with other component interference if the noise floor is in similar level. The showed example of problematic component was Mobius HD camera, I showed graph of noise floor and showed graph of measured noise floor of Mini APM 2.7.2 and gave it to you honestly for comparison. Everybody knows of what huge UHF noise floor of Mobius HD can cause to UHF control, you can find it on internet. I gave you this to think about it honestly. But you simply ignore this and other facts mentioned and simply saying "no evidence". I also showed noise floor of 2.4 GHz 500mW transmitter for comparison. Only crash with your copter and or airplane would tell you that in that case, but luckily with APM we have autopilot which handles situation for us. But that does not mean we should ignore options for possible improvements, but rather think about possible improvements.