Engine noise in aeronautical communication.

[RicardoNunes]

Hello how are you? I fly a paramotor. When talking to other pilots the communication is with engine noise. I use an electret microphone with noise cancellation but it is not enough. Is there an electronic circuit that can solve this problem? My radio does not need a preamp. It is not aeronautical radio. Thanks

 

[unclejed613]

i'll try to draw a circuit for this later, but i have seen professional microphones that use two elements and use some method of subtraction, either direct wired in opposite phase (you can't do this with electrets) or an op amp with the two microphones going into the differential inputs (one mic to the inverting input, and one going into the noninverting input). the microphones are then mounted a couple of inches apart, but you only speak into one of them. since the in phase signals (the ambient noise) are equal in both microphones, they cancel. you speaking into one of the microphones and not the other creates a signal that doesn't exist in the other microphone, and the signal passes through rather than cancelling.

 

[audioguru]

Why are airplane piston engines extremely noisy? I can barely hear my much more powerful car engine but an airplane so far away I can barely see it makes a tremendous noise. I think they design them to be noisy.
My son bought a Ford Fusion car with a V6 dual turbo engine. It plays the roar of a much larger engine in its radio speakers. With its windows up you can barely hear it drive past.

 

[Nigel Goodwin]

Why are airplane piston engines extremely noisy? I can barely hear my much more powerful car engine but an airplane so far away I can barely see it makes a tremendous noise. I think they design them to be noisy.

Fairly obviously power is crucial to an aircraft engine, silencing it loses you power (why do you think racing cars are loud as well?), hence the design is for maximum power not throwing power away to make it quieter.

 

[audioguru]

An airplane is not at full power all the time, its power is reduced when cruising for most of its time. It should use a lightweight muffler when cruising and have it "open-up" only when the power is needed.
A racing car almost never cruises. A Ford Mustang car has three buttons: loud, louder and loudest but I don't know if it affects its power.
Many sports cars (Lamborghini) and most motorcycles are made to be very noisy.

 

[Nigel Goodwin]

An airplane is not at full power all the time, its power is reduced when cruising for most of its time. It should use a lightweight muffler when cruising and have it "open-up" only when the power is needed.
A racing car almost never cruises. A Ford Mustang car has three buttons: loud, louder and loudest but I don't know if it affects its power.
Many sports cars (Lamborghini) and most motorcycles are made to be very noisy.

Again, same reason - more power.

Won't be a problem with EV's though!

 

[unclejed613]

Won't be a problem with EV's though!

there is a slight problem there for aircraft in power-to-weight ratio carrying a load of batteries...

 

[Nigel Goodwin]

there is a slight problem there for aircraft in power-to-weight ratio carrying a load of batteries...

I suggest you try googling Elon Musk!

 

[RicardoNunes]

i'll try to draw a circuit for this later, but i have seen professional microphones that use two elements and use some method of subtraction, either direct wired in opposite phase (you can't do this with electrets) or an op amp with the two microphones going into the differential inputs (one mic to the inverting input, and one going into the noninverting input). the microphones are then mounted a couple of inches apart, but you only speak into one of them. since the in phase signals (the ambient noise) are equal in both microphones, they cancel. you speaking into one of the microphones and not the other creates a signal that doesn't exist in the other microphone, and the signal passes through rather than cancelling.

Thanks for the answer. I liked the idea. When you can, submit your project. thanks.

 

[Ylli]

Why are airplane piston engines extremely noisy? I can barely hear my much more powerful car engine but an airplane so far away I can barely see it makes a tremendous noise. I think they design them to be noisy.

The majority of the noise you are hearing is that big paddle out front beating the air into submission.

 

[Ylli]

I fly a paramotor. When talking to other pilots the communication is with engine noise.

Are you taking about audio noise being picked up by the microphone, or electrical noise generated by the motor?

 

[unclejed613]

Are you taking about audio noise being picked up by the microphone, or electrical noise generated by the motor?

i'm pretty sure he's talking about mechanical/propwash/wind noise... i gather he's using uhf fm walkie talkies, and i doubt there's much RFI from the engine

 

[RicardoNunes]

i'm pretty sure he's talking about mechanical/propwash/wind noise... i gather he's using uhf fm walkie talkies, and i doubt there's much RFI from the engine

Exactly. It is not interference noise.
It is ambient noise. Engine sound.