[Elecraft] K3S Noise reduction Test

John Stengrevics jstengrevics at comcast.net
Wed Jun 21 12:38:26 EDT 2017


Jim,

Is there a similar unit that covers 50 MHz?  Or, a way to modify the NCC-1/NCC-2?

73.

John
WA1EAZ

> On Jun 21, 2017, at 12:33 PM, Jim Brown <jim at audiosystemsgroup.com> wrote:
> 
> 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...
> 
> 
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