[Elecraft] dB Changes, Loudness, and Signal to Noise Ratio

[Alan Bloom]

On Tue, 2009-12-15 at 11:14 -0800, Kok Chen wrote:
> On Dec 15, 2009, at 9:52 AM, Jim Brown wrote:
> 
> > ...we are working on the signal to noise ratio, NOT LOUDNESS. It's apples and 
> > oranges!  The only thing in common is that we're using a log ratio to 
> > describe it. 
> 
> I couldn't agree more with Jim on this one.

I also agree.  On the other hand, in actual on-the-air operation you
almost never have a constant signal-to-noise ratio.  With typical fading
and interference coming and going, I seriously doubt you could ever
notice a 1 dB change in power level.  During 99% of the QSO the signal
is either well above the threshold of copy-ability or well below.  It
would be very rare that a 1 dB increase in power could turn a
non-contact into a valid QSO.

On the other-other hand, even if 1 dB made the difference in only one
contact in a thousand, that might be very important to a world-class
contester.  At that level of competition, a 0.1% increase in contacts
could be the difference between winning and losing.

So I think the bottom line is that 1 dB would make no discernable
difference in casual operation.  But for someone contesting at the
highest levels. that is, someone who has a serious chance of winning a
CQWW or a Sweepstakes, a 1 dB improvement is very worthwhile.

Al N1AL