In my eyes what could become tiresome in the long run is constantly raising the red flag without feeding us a single element that would corroborate your "I have seen it and it's enough" attitude.
If you are saying that 2 Watts of radiated RF can not possibly interfere with onboard equipment, then you sir are quite misinformed. Period. A 2 Watt signal can be easily received 50 miles away or more. If a cell phone can't transmit a field that is usefull 3.5 metres away, how do you expect it to communicate with a cell tower miles away?
For you information, 2Watt of RF signal at 800MHz can be perfectly received at several hundred kilometers, provided there is an adequate antenna and adequate receiver at the other end.
But what will arrive over there is an electric field of the order of tenths of a microVolt, that is 7 digit after the dot.
What you need to produce (off band) RF interference is a few millions time that much.
Now maybe you can answer me this…when you put your cell phone next to your computer and you observe interference, is it because the computer is operating at 900MHz? Why is there a buzz in the speakers? Why does your monitor act strange? Remember my statement about lower band emissions that digital cell phones emulate?
When I put a cellphone next to a PC
nothing happens, sorry.
When I put it next to a display with a cathode ray tube, the latter flickers, right. But I suppose you know why. If not, I'll tell you that a display is by its own nature an open case, not a shielded device. The electric field produced by your cellphone at a very short distance is enough to alter the field created by the deflection coils around the CRTube. That's all there is, and the weak link in this is not the cellphone but the display. (ps no problem with TFT since they have no deflection coils)
Buzz in the speakers, sure, you know why ? same thing, the speaker magnetic fied is disturbed. Put alu paper around your speaker, or move further away by half a meter, problem solved.
clicks in headsets ? disturbance of the speaker magnets. Put a sheet of paper on top of your head and tell me what happens.
Lower band emissions ? here you are on your own and you show you are not at ease with RF circuits. Any device made to radiate energy does so at the intended frequency (aka f0), but some spurious (unintended) radiation will also appear on higher frequencies, not lower. These unwanted signals are the by product of non-linearity in amplifying circuits, resulting in largely attenuated but still present signals on frequencies called "harmonics" and corresponding to 2 x f0, 3 x f0, etc...
I obviously can’t stop you from speaking your mind in a public forum, but I think I’ve presented a great deal of information and personal experience to support my statements…to no avail.
You have presented nothing at all. You only mentioned that you saw things.
To come back to your last example, I reiterate my question, did you identify the faulty component ?
Because there was something wrong. The FD
/AP system is no intrinsic receiver and clearly is inside a chassis and shielded/grounded and so are the various cables and harnesses. Any interference susceptible to alter the functions of the unit have to be brought inside directly along a wire, not by mere radiation of a 2V electric field. Nonsense.
In all honesty, tell me that a cellphone put next to the FD
/AP unit (correctly installed and grounded), does interfere.
If it was so, there is not a single aviation authority in the world that would allow pax carrying cellphones onboard, even switched off.