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If you have S3+ noise floor on your base and access to the internet - read this

Dr_DX

WDX-861
Jan 29, 2006
583
870
103
ATM, I just have a quick & dirty Imax 2000 up at 25' with no grounding or ground plane and about S5 ambient noise floor. I know I can do a lot of things to lower/eliminate it - but that's not the point of this post. I was Googling QRM elimination and ran across a software program that uses AI to filter/eliminate your RX noise. Basically, it takes your radio's RX audio connected to your computer's "line in", sends it via UDP packets to Servers in Texas or Switzerland, AI processes it, and sends it back to your computer where you listen to it via your headphones/speaker in real time. Average latency is 150-250ms.

I was skeptical but it was free and I figured if it didn't work, I was only out some time. The program is called RM Noise and you can DL the ad free Windows Client here:


There is documentation on the site and a forum as well. Just install the client software and then run your radio's external speaker into your computer's "line in". Turn your radio's volume all the way down, set your "Line In" and your "Output" to "100" on the volume slider in Window's "Sound" settings:

1726550612670.png


Under "Input", click on "Device properties":

1726550744178.png


Crack open the "volume" on your radio and click on "Start test". Let it run for 10 seconds and then "Stop test". NOTE: you won't hear anything while doing this.

1726550967072.png


1726551005382.png


Set your radio's volume level to give a highest value of 15~20%. In my limited testing, this setting seems to give the best S/N ratio. Not now, but later if the volume isn't loud enough, there is an output volume control in the application that can be adjusted to your liking depending on your output device (headphone or speaker).

I recommend low impedance circumaural headphones that use a 3.5mm plug that can be plugged in directly to the computer's line/headphone out.

You will need to create an account on the website; it will ask you to use your callsign, but you don't have to - the username & password are case sensitive. When you start up the client software, it will ask for a login - set to "stay logged in" and you only have to do it once.

1726553768843.png


My settings:

1726551883581.png


There are 5 different AI filter options:

1726551983310.png


Other than DSP filter set to "Sharp", it is important to turn off all other Noise reduction / Noise blanking on the radio. Under "options", you can set the different input and output options and "activate settings" to select them:

1726552334247.png


There is a "volume" slider on the main window so you can turn up or down the output volume to your liking. Using headphones, I set my volume to .5.

In use, I have seen default "delay" values from 150~250ms. it all depends on your Internet latency to servers in Texas (2) or Switzerland - the software selects the server with the lowest latency.

The filtering slider can be set from "Original (no filtering) to 1.00 (100% filtering). I prefer to set mine from .97~.98 for just a hint of hiss.

If you have a unique noise that the AI can't remove, you can make a 30 minute recording of it and submit it for "training" the AI.

With these settings, I can hear and "copy" an "audio only" signal that is totally buried under my S5 noise floor.

I just had a QSO with world radio 304 Sydney Australia on .385 @ 1:32am in the morning my time - he was giving me an "audio only" signal.

I hope this can help those users that have a high noise floor - it certainly has helped me hear and copy weak stations that otherwise I would never even know they were there.

73's
 
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I have used RM Noise with a Hermes Lite 2, with Thetis. It's performance is actually amazing. I have almost zero noise floor at my QTH anyway, but the ability for RM to pull signals from below the noise floor is incredible. The only "annoyance" for me is the round trip processing delay, and the requirement for an internet connection.

73
 
I have used RM Noise with a Hermes Lite 2, with Thetis. It's performance is actually amazing. I have almost zero noise floor at my QTH anyway, but the ability for RM to pull signals from below the noise floor is incredible. The only "annoyance" for me is the round trip processing delay, and the requirement for an internet connection.

73
Talk to the owner. He is looking for locations/countries to setup servers. If you are willing to host a server, there is a good chance he will let you. Then your latency issues are gone. No servers in Australia yet - be the first.

He won't let people run it locally on their computer - people have asked in the forum.
 
  • Like
Reactions: Pez
Maybe you should install that antenna properly first?
Mike
LOL, Mike.

As mentioned - quick & dirty & temporary. No sense spending any time or effort on it - it isn't going to be used long term.

The post isn't about me complaining at all. When I set things up correctly, with a better antenna, I don't have any noise.

It is about a product that I ran across that I thought was very effective and might be of help to some other forum member/s.

It isn't for everyone.

73's
 
  • Like
Reactions: buickid and Pez
Well, all that may be well and dandy, but I am one that does not desire to have to use an external computer in order to use my transceiver, at all .......
As posted above, ensure the antenna system is installed correctly and trace down the interference......
Just sayin' ........
 

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