Re: Continuum mode


jdow
 

Figure one signal is present, a unit gain (0 dBfs) sinewave. Without shaping it will appear in one or two bins ideally. You take the power level for all bins within the bandwidth Y and sum their power, not voltage, of course. It's independent of the X bandwidth. Scaling would be the same as you use for the spectrum display.

Or take the FFT array of values, multiply each cell by your calculated IF filter shape, pick a bundle of values around the center of the filter to get a nice power of two bin count, take reverse FFT, pseudo power = I^2 + Q^2, Nominally ir should have scaling to make that come out as 0 dBfs for that single sinewave signal. Then the real world should sort of fall out of what you have with no further work. (Yes, I am fixated on I^2 + Q^2 pseudo power.)

{O.-}

On 20220317 03:45:40, Simon Brown wrote:

Typo.

 

Given:

  • Center frequency & bandwidth with have a count of FFT bins = X (values in dBm)
  • Resolution bandwidth = Y Hz

 

What’s the formula for the actual continuum value when these X bins are used?

 

Simon Brown, G4ELI

https://www.sdr-radio.com

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Simon Brown
Sent: 17 March 2022 10:39
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Continuum mode

 

So,

 

Given:

  • Center frequency & bandwidth è Count of FFT bins = X (values in dBm)
  • Resolution bandwidth = Y Hz

 

What’s the formula for the actual continuum value when these X bins are used?

 

Simon Brown, G4ELI

https://www.sdr-radio.com

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Conrad, PA5Y
Sent: 17 March 2022 09:49
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Continuum mode

 

Hello Simon, I really appreciate you adding this feature. I do have SpectraVue and an SDR-IP and in the past like Charles I used SDRC with Perseus and the IQ outputs as inputs for SpectraVue. Very cumbersome!

 

Let’s get it working and then I have some other ideas.

 

This will be really useful.

 

73

 

Conrad PA5Y

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Simon Brown via groups.io
Sent: 15 March 2022 06:42
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Continuum mode

 

Hi,

 

That’s fine. I can get almost all work done, then there’s fine tuning. I think a docking window like the Signal History is the correct solution.

 

Simon Brown, G4ELI

https://www.sdr-radio.com

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of sm6fhz
Sent: 14 March 2022 21:48
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] Continuum mode

 

Hi.
Here is an early message (May 2014) with an tentative short-spec for the Continuum Mode:
https://sdr-radio.groups.io/g/main/message/23048
73 / Ingolf, SM6FHZ


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