Whistling noise in audio

Whistling noise in audio

Post by <kuzen.. » Thu, 02 Aug 2007 01:21:56

For many years I've kept a scanner at work to listen to the air-ambulance
helicopters come and go--I just find the choppers interesting.

Moved to a new job last month in Louisville, KY.  Just out of curiosity, I
added the listed frequency (464.1375) for the excursion boat _The Belle of
Louisville_ to my scanner.  (I took the two-hour ride this weekend and it
was a lot of fun.)

So I do hear activity from the _Belle_, but there's a warbling sort of
audio tone on all their transmissions.  Sounds like someone blowing a
slide-whistle while working the slide up and down.  Don't know that I've
ever heard that before.

Is this something designed to discourage listening?  (In my case,
sometimes the warbling isn't very loud in the audio stream, and at other
times it's loud enough to make it difficult to hear what they're saying--I
have no idea why it varies like this.)  Or is the warbling for some other
reason?   TIA.

 _______________________________________________
 Ken Kuzenski AC4RD atsign mindspring dotsign com
 _______________________________________________
All disclaimers apply, see?  www.duke.edu/~kuzen001

 
 
 

Whistling noise in audio

Post by mikeFN » Fri, 03 Aug 2007 08:12:24


***radio or maybe even ***generator onboard producing rubbish AC waves.
else its hetrodyning with another local transmitter.
why dont you bung up an mp3 of it somewhere and we could listen to it.
might even be a birdie in you scanner IF.

mike


Quote:

> For many years I've kept a scanner at work to listen to the air-ambulance
> helicopters come and go--I just find the choppers interesting.

> Moved to a new job last month in Louisville, KY.  Just out of curiosity, I
> added the listed frequency (464.1375) for the excursion boat _The Belle of
> Louisville_ to my scanner.  (I took the two-hour ride this weekend and it
> was a lot of fun.)

> So I do hear activity from the _Belle_, but there's a warbling sort of
> audio tone on all their transmissions.  Sounds like someone blowing a
> slide-whistle while working the slide up and down.  Don't know that I've
> ever heard that before.

> Is this something designed to discourage listening?  (In my case,
> sometimes the warbling isn't very loud in the audio stream, and at other
> times it's loud enough to make it difficult to hear what they're saying--I
> have no idea why it varies like this.)  Or is the warbling for some other
> reason?   TIA.

> _______________________________________________
> Ken Kuzenski AC4RD atsign mindspring dotsign com
> _______________________________________________
> All disclaimers apply, see?  www.duke.edu/~kuzen001