Point taken Jim,
Thanks and 73,
Joe kk0sd
-----Original Message-----
From: RFI <rfi-bounces+gary_mayfield=hotmail.com@contesting.com> On Behalf Of
Jim Brown
Sent: Wednesday, March 24, 2021 1:26 PM
To: rfi@contesting.com
Subject: Re: [RFI] New Interference at kk0sd
There is a LOT of great advice in this post, but I'll zero in on this one, on
the basis of my professional background in psychoacoustics (the science of how
our brains process what we hear). There's a fundamental property of human
hearing behind the success of what Ed describes. Human hearing is FAR more able
to hear differences in the loudness of one sound compared to the other when
they are more nearly equal. The two sounds here were the arcing sound and the
broadband circuit noise.
Also, we humans have very poor sensitivity to the loudness of a sound.
It takes a change of 6-10 dB for us to perceive a sound as twice as loud (or
half as loud), but a change of only 1-2 dB in the strength of a signal that is
very close to the noise level can be the difference copy or no copy. And when I
was recording mixing live sound for a jazz band, I rarely needed to move faders
more than a dB or two once I had the mix "right" musically.
73, Jim K9YC
On 3/23/2021 11:27 PM, Hare, Ed, W1RFI wrote:
> I had a step attenuator, so I decided to try a trick. I drove to about
> where I thought it was strongest. I listended to the raucous buzz (120
> Hz) and cranked in attentuation until the buzz dissapeared and all I
> heard was white noise from the receiver. I cranked back until I could
> JUST barely hear the buzz over the white noise of the receiver. My
> ear was pretty good at that. I again drove the line and heard it
> louder as I drove past a
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