[Amps] Getting rid of blower noise

[k7fm]

I have another suggestion - or more correctly called "fighting noise with 
noise".

WARNING:  this is one of those ideas that would come out after a few hams 
with big amplifiers were sitting around during the low sunspot cycle 
imbibing, and is not based upon research or special knowledge:

Since big amplifiers need air and air movement necessarily makes noise, one 
approach would be to simply make the noise invisible by picking up the noise 
and generating out of phase noise to cancel out the actual noise generated. 
What you cannot hear would not be objectionable.  In aircraft, we use noise 
candelling microphones and headsets.  The announcers at noisy events speak 
into the microphone with almost no interference from the loud noise at the 
event.

So, what we need are noisy fans which generate anti-noise.

Colin  K7FM