We seek to understand and document all radio transmissions, legal and otherwise, as part of the radio listening hobby. We do not encourage any radio operations contrary to regulations. Always consult with the appropriate authorities if you have questions concerning what is permissible in your locale.

Author Topic: Stereo Tool Absolute Highs DSP Filter  (Read 3473 times)

Offline RobRich

  • DX Legend
  • ******
  • Posts: 1722
  • Tampa, FL USA
    • View Profile
Stereo Tool Absolute Highs DSP Filter
« on: April 16, 2018, 0145 UTC »
Do not expect a miracle, but the Absolute Highs filter in Stereo Tool can sometimes help reproduce another KHz or few when listening to narrow content.

https://www.stereotool.com/

For a quick setup, configure the maximum generation setting at or slightly below the top edge of your current filtering and/or received bandwdith. Bump up the gating if needed to process more of the desired content instead of background noise.

Content is the huge YMMV factor. For example, forget it with lots of noise IMO, as it likely is going to enhance the noise as much as the desired content.

Pictured below is an 80m band voice comms example. Filter width is just 2.7KHz to limit adjacent interference, but it sounds considerably wider with the Absolute Highs filter enabled.
« Last Edit: April 18, 2018, 0103 UTC by RobRich »
Tampa, FL USA | US Map Grid EL88
Airspy HF+ Discovery | KiwiSDR 2 | 2x Msi2500 Msi001 | 2x RTL-SDR V3 + NE602 | 2x RTL-SDR V4
148' Loop-on-Ground | 31' Vertical | 18' End-Fed Vertical | 9' NCPL | PA0NHC MiniWhip

Offline redhat

  • DX Legend
  • ******
  • Posts: 1585
  • USA
  • Music is my drug.
    • View Profile
    • Email
Re: Stereo Tool Absolute Highs DSP Filter
« Reply #1 on: April 17, 2018, 0519 UTC »
Does the 'delossifier' have a similar effect?  I think it is intended to fill in spectral holes left by MPEG compression.  Hans' declipper and dehummer process works amazingly well too.

+-RH
« Last Edit: April 17, 2018, 0522 UTC by redhat »
Somewhere under the stars...
Airspy HF+, MLA-30/Mini-whip/Chi-Town Loop
Please send QSL's and reception reports to xfmshortwave [at] proton [d0t] me

Offline RobRich

  • DX Legend
  • ******
  • Posts: 1722
  • Tampa, FL USA
    • View Profile
Re: Stereo Tool Absolute Highs DSP Filter
« Reply #2 on: April 17, 2018, 2217 UTC »
As far as I understand, Delossifier mathematically fills spectral holes in existing spectrum while Absolute Highs mathematically generates additional spectrum.

I do not have a Delossifier license.... yet? Have not made up my mind on the cost.

I occasionally use Perfect Declipper as well since lots of transmissions, including some of the mainstream broadcasters, are heavily clipped.
Tampa, FL USA | US Map Grid EL88
Airspy HF+ Discovery | KiwiSDR 2 | 2x Msi2500 Msi001 | 2x RTL-SDR V3 + NE602 | 2x RTL-SDR V4
148' Loop-on-Ground | 31' Vertical | 18' End-Fed Vertical | 9' NCPL | PA0NHC MiniWhip

Offline RobRich

  • DX Legend
  • ******
  • Posts: 1722
  • Tampa, FL USA
    • View Profile
Re: Stereo Tool Absolute Highs DSP Filter
« Reply #3 on: April 18, 2018, 0100 UTC »
Processing reception of Seven Trees Radio tonight.
Tampa, FL USA | US Map Grid EL88
Airspy HF+ Discovery | KiwiSDR 2 | 2x Msi2500 Msi001 | 2x RTL-SDR V3 + NE602 | 2x RTL-SDR V4
148' Loop-on-Ground | 31' Vertical | 18' End-Fed Vertical | 9' NCPL | PA0NHC MiniWhip