[Elecraft] K3S Noise reduction Test

[Jim Brown]

Yes, the NCC-1 is a superb unit, especially for use on 160, 80, and 40M. 
It's usefulness diminishes above 30M.  I'm using one to phase a spaced 
pair of VE3DO loops that are physically aimed at EU. Using the NCC-1, I 
can shift the pattern +/- 20-30 degrees. The combined loops produce some 
pretty deep (and narrow) nulls, so it's often possible to peak the 
signal while nulling a single noise source.

VE3DO loops are rectangular receiving loops that are 40 ft long by 10 ft 
high, with the lower horizontal segment about 2 ft off the ground. The 
loops are optimized for 160M, but work well on 80M. They're spaced 5/8 
wavelength on 160, which is about 350 ft. The spaced pair has 
directivity similar to a full wavelength Beverage, but the vertical 
pattern is broader for the loops, so the two antennas complement each 
other for signals arriving at different vertical angles.

http://www.ok1rr.com/index.php/onair/8-qmgr

The great thing about the NCC-1 is that as the phase knob is rotated, 
the phase difference is a nearly linear straight line, AND the amplitude 
difference is quite small. On 160 and 80, the difference is less than 
about 0.15 dB; it's a bit greater on 40M, and about 0.5 dB on 20M. That 
flatness makes it FAR easier to tune than its lower cost alternatives.

As others have noted, noise cancellation works only for a single source 
at a time.

73, Jim K9YC

On Tue,6/20/2017 9:45 PM, tomb18 wrote:

> I think the ncc1 is under rated. Here is an example  of what it can do.
> Just a note. This is with a small amplified  vertical receive antenna, the ncc1 and all fed through the k3 Rx loop. It's wwv, and the whole thing is switched in at the end of the video. 25dBm reduction in the noise. It's also really useful for eliminating acting one signal on top of the other. For example Am broadcast dxing... I can get rid of a strong am broadcast on top of a weak one. Now if only this could be automated and built in to the radio...