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:
Under "Input", click on "Device properties":
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.
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.
My settings:
There are 5 different AI filter options:
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:
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
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:
RM Noise – Removing noise with AI
ournetplace.com
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:
Under "Input", click on "Device properties":
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.
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.
My settings:
There are 5 different AI filter options:
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:
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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