SV3ORA NR-1 Noise Blanker Project

[RobRich]

Hat tip to Thom's SWLing Post:

NR-1 is a revolutionary Noise Blanker which is the product of two-years of development and extensive testing by Kostas sv3ora.

NR-1 works directly at the antenna. This has significant advantages over the classic noise blankers which work at the intermediate stages of the receivers. It does not require a second “noise” antenna for its operation.

Furthermore, it is not based on cutting-off of amplifiers, unlike common noise blankers do.

Because of these, the NR-1 is superior, compared tocommon internal Noise blankers of radios....

Source: https://swling.com/blog/2024/05/kostas-releases-the-nr-1-noise-blanker/

Kostas (SV3ORA) has a PDF manual, demo videos, etc. here:

* Remove that annoying noise before it reaches your transceiver.

* This is NOT a QRM-eliminator/X-phaser, it does not use a separate antenna and it removes noise from any direction simultaneously.

Source: http://qrp.gr/nr1/

I already have an unit on order. :)


As per The SWLing Post:

Update June 1, 2024: Kostas is not currently selling the NR-1 as a product but has, instead, made the entire project open and available for everyone to build their own. You may contact him for more information.

[RobRich]

Couple of quick screenshots in somewhat different configs. Usual afternoon RFI in the area. Bottom of waterfall is NR-1 off. Top of the waterfall is NR-1 on. I am still learning the fine tuning.


(click to enlarge)


(click to enlarge)

Also I need get it on a better power supply plus get a RF choke near the input side as it is straight to my antenna feedline right now.

[sv3ora]

I am glad it does a good job for you
Currently, I experience the same type of noise like you do, lots of horizontal lines at the waterfall, in fact more of them. The internal noise blanker of my rig can usually cope with the audible noise (inducing the typical distortion on high level signals), but it cannot clean the waterfall (since it works in the IF only). The NR-1 is a saver in this case and cleans the whole waterfall spectrum without distortion. Actually, I have shot a video of this action here https://www.youtube.com/watch?v=bkbPVVcN6i8&list=PL0KwxiKZqJ1TzQpscf3voh5CR1c30WLD_

Thanks so much for posting the screenshots, these are valuable. I find it much easier to tune it using the waterfall, as I can see the whole band and I can notice (by switching on/off) any IMD produced in the whole band, so that I can back up the gain a bit. In my situation, I keep the balance close to 90% all the time and the gain control at around 20% or so. Then I play around with the output to bring the band background noise to the levels that it normally has without the pulsating noise (I notice the color of the waterfall in between the noise pulses). If it intermodulates, I back up the gain control just a tiny bit, or I turn the IMD clockwise. In the higher bands, the IMD and the gain can be turned clockwise and in the lower anti-clockwise. In the lower bands in the mornings, where DX signals are usually not present, I can turn the gain more clockwise and the IMD more anti-clockwise than in the evenings.
The exact settings depend on your noise levels and type, but this is generally how I set mine. I guess you have seen the newer youtube videos of my tests on the NR-1.

I am working on a modification that has steeper preselection to avoid even more the IMD, thus allow lower noise levels to be attacked. As soon as I finish, I will post this modification to the website. It is something that you can apply easily if you are interested in that. I will let you know.

[RobRich]

New SV3ORA videos including his NR-1 noise blanker paired with an Icom 7300.

https://www.youtube.com/@sv3ora/playlists

Hat tip to Thom at swling.com. :)

The NR-1 is a neat device, and it does work quite nicely for its intended purpose. I just have not had much time (yet) to further test mine in more varied operating situations, as much of my recent radio time has more about getting my KiwiSDR 2 online and some antenna experimenting.