Improve the FM audio

[Phil - NY4Q]

frontend/src/audio.js

Code Select Expand

      case 'FM':
        this.bassBoost.gain.value = 50
        this.bandpass.frequency.value = 2200
        this.bandpass.Q.value = 0.6
        this.bandpass.gain.value = 3
        this.highPass.frequency.value = this.ctcss ? 300 : 30
        this.presenceBoost.gain.value = 4
        this.setLowpass(4800)
        break

npm install
npm audit fix
npm run build

[Emmanuel SV1BTL]

frontend/src/audio.js

Code Select Expand

      case 'FM':
        this.bassBoost.gain.value = 50
        this.bandpass.frequency.value = 2200
        this.bandpass.Q.value = 0.6
        this.bandpass.gain.value = 3
        this.highPass.frequency.value = this.ctcss ? 300 : 30
        this.presenceBoost.gain.value = 4
        this.setLowpass(4800)
        break

npm install
npm audit fix
npm run build

How to solve this after running npm to compile?

file:///home/sv1btl/PhantomSDR-Plus/frontend/node_modules/vite/bin/vite.js:7
    await import('source-map-support').then((r) => r.default.install())
    ^^^^^

SyntaxError: Unexpected reserved word
    at Loader.moduleStrategy (internal/modules/esm/translators.js:133:18)
    at async link (internal/modules/esm/module_job.js:42:21)

[Phil - NY4Q]

I believe I ran through these steps and fixed that error. I stopped at the point of checking the version of node.

Code Select Expand

https://linuxize.com/post/how-to-install-node-js-on-ubuntu-20-04/#installing-nodejs-and-npm-using-nvm

I will add - while this improved the pinched audio I was hearing on VHF-FM, I still do not like what I'm hearing as compared to the same SDR (in my case an RSP1a) and SDR Console.

[Emmanuel SV1BTL]

I believe I ran through these steps and fixed that error. I stopped at the point of checking the version of node.

Code Select Expand

https://linuxize.com/post/how-to-install-node-js-on-ubuntu-20-04/#installing-nodejs-and-npm-using-nvm

I will add - while this improved the pinched audio I was hearing on VHF-FM, I still do not like what I'm hearing as compared to the same SDR (in my case an RSP1a) and SDR Console.

Followed all the steps - Success!
After recompile, FM mode is much better now!

Thanks!

[Phil - NY4Q]

I landed on Bas' SDR today and found some stations using FM on 11 meters and that FM sounded great. So why does VHF/UHF FM sound so pinched up and also have so much hissing involved?

[Emmanuel SV1BTL]

I landed on Bas' SDR today and found some stations using FM on 11 meters and that FM sounded great. So why does VHF/UHF FM sound so pinched up and also have so much hissing involved?

I don't know if BAS has made the modification you've recommended, but in my case, FM stations on 11 meters sound really better.

[Bas ON5HB]

I did not modify the FM-code.

Beware, that Soapy isn't as good as the RX888MK2 direct sampling-injection.

Soapy does have some strange things AND does convert if needed.

When you are able to avoid Soapy, you better do so.

When it comes to the RSP1A and older devices, you can pick between the 2.13 and 3.xx API, I really suggest you use the 2.13 API and use the 2.13 plugin, it's far better. Also more stable.