[Elecraft] K3 and Preamp

[W2RU - Bud Hippisley]

On Sep 6, 2014, at 2:34 17PM, Dauer, Edward <edauer at law.du.edu> wrote:

> I received a couple of off-list comments that might be of interest to
> those who are following this thread.  One was that narrowing the BW also
> improves the S/N. 

Maybe.  Maybe not.  Or, maybe up to a point.

I believe that whether one observes monotonic improvement in ability to decipher the intelligence carried in a very weak signal as one reduces receiver BW will be a function of _how_ the BW is narrowed in the various electronic circuits and/or digital algorithms, as well as a function of our own individual hearing characteristics.

Perhaps I am not on the main part of the normalcy distribution curve (my close friends will assure me I’m _not_!) but I know for a fact that many, many times I have been best able to pull intelligible information out of a very weak CW signal on the low bands by using a receiver BW somewhat _wider_ than that provided by my narrowest filtering options.  I have used primarily Kenwoods and (more recently) the K3 for most of my serious low-band DXing efforts, but I can’t tell you if this effect is more or less apparent in one model vs. any other. 

I am also a strong believer in what I have been told is “stochastic resonance” as an aid to hearing and copying the intelligence carried in weak signals.   I have found repeatedly, for instance, that I am more apt to hear certain “unusual” vehicle sounds from the engine compartment or underbody when I have the car radio playing music within a certain range of amplitudes.   Of course, that might also depend on my choice of music genre … :-)

Bud, W2RU