TopBand: Noise Canceller

[Ward Silver]

> I've read the pros/cons/anecdotes regarding the JPS ANC-4 and
> its brethren. But the thought occurs to me: Can the same noise
> cancelling technique be used at audio frequencies and still
> achieve the same goal?
> 
> 73 Kris N5KM 

Yes.  Plantronics (and several other manufacturers) make noise-cancelling
headsets for aviators who would otherwise go deaf from cockpit noise.  The
pilots of the Voyager, Gary (?) and Deanna Yaeger, wore prototypes of this
headset on their round-the-world-without-refueling flight a few years ago.

Also, some automotive manufacturers are developing noise-cancelling
mufflers to reduce exhaust noise.  Imagine...an active muffler!!

Another application for RF noise-cancellers is to reduce overload from a
loud, nearby station, by the way.  As they move around, you have to keep
tweaking it, but if you're near a ham with an amp, it can occasionally
save your sanity!  I've tried it on BC stations with some success,
although a filter works better.

73, Ward N0AX

 -
 ---
FAQ on WWW:               http://www.contesting.com/topband.html
Submissions:              topband@contesting.com
Administrative requests:  topband-REQUEST@contesting.com
Problems:                 owner-topband@contesting.com