[Elecraft] [K3] The Way We Rank Receivers (long)

[Walter Underwood]

Well, “advancing skills in both the communication and technical phases of the art” and all that. Funny how S2 noise was silent, even on a wilderness peak.

wunder
K6WRU
Walter Underwood
CM87wj
http://observer.wunderwood.org/ (my blog)

> On Oct 27, 2016, at 5:55 PM, Edward R Cole <kl7uw at acsalaska.net> wrote:
> 
> Walter,
> 
> Have to chuckle - "ask what one thought would be rhetorical question" and some one gives you an answer!
> 
> Well, if you can get away from modern civilization and run without ac power low noise conditions can be found.
> My KX3 is out mounted in my truck so don't have it to test.  I did turn on my K3 connected to triband yagi and am seeing S5 noise "floor" where there are no signals (preamp off).  Checking 6m I also see S5 but this is pointed at a local noise source and with ext Gasfet preamp on.  If I turn the 6-element yagi 90-degrees the noise level drops to as low as S3 with preamp on (K3 needs some kind of preamp when using 6m).  I also have the PR6-10 which I use on HF or 6m if I turn on DIGOUT-1 which energizes the PR6-10 and disconnects the ext preamp.  It shows about one s-unit lower noise due to less gain than the Gasfet.
> 
> But with "two bars" if you actually measured noise power it would probably still be about -120 dBm or higher.  Still on HF that is *quiet*.
> 
> 73, Ed - KL7UW
> 
> From: Walter Underwood <wunder at wunderwood.org>
> To: Elecraft at mailman.qth.net
> Subject: Re: [Elecraft] [K3] The Way We Rank Receivers  (long)
> 
> 
> > On Oct 25, 2016, at 2:31 PM, Edward R Cole <kl7uw at acsalaska.net> wrote:
> >
> > I wonder where in the world one sees a 20m noise floor that low when antenna is connected?  Only when I lived off the grid running on battery power did I see S0 noise on my radio (3.9-KHz with TS180S from a dipole).
> 
> Good point. Looking at the photo of my KX3 on top of Mount Willson in Henry Coe, I see two bars on the S-meter on 20 meters. That is miles from Silicon Valley. It was quiet and lovely, I could hear everybody. The filters were wide open, preamp on, and NR off. Zoom in and you can see for yourself.
> 
> https://www.flickr.com/photos/walter_underwood/17417496311/in/album-72157652448882921/ <https://www.flickr.com/photos/walter_underwood/17417496311/in/album-72157652448882921/>
> 
> wunder
> K6WRU
> Walter Underwood
> CM87wj
> http://observer.wunderwood.org/ (my blog)
> 
> 
> 
> 73, Ed - KL7UW
> http://www.kl7uw.com
>    "Kits made by KL7UW"
> Dubus Mag business:
>    dubususa at gmail.com
> 
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