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Technical Topics => SDR - Software Defined Radio => Topic started by: 8 tattoos on March 31, 2018, 1722 UTC

Title: AirSpy HF+ and SSTV decoding
Post by: 8 tattoos on March 31, 2018, 1722 UTC

I have MMSSTV installed. If an SSTV signal is detected and I launch MMSSTV will it decode it?

Title: Re: AirSpy HF+ and SSTV decoding
Post by: ChrisSmolinski on March 31, 2018, 1753 UTC

Only if you route the audio from your SDR software to your SSTV app via a virtual audio device.

Title: Re: AirSpy HF+ and SSTV decoding
Post by: 8 tattoos on March 31, 2018, 1803 UTC

How would I do that? And where would I find a virtual audio device?

Title: Re: AirSpy HF+ and SSTV decoding
Post by: radiogaga on March 31, 2018, 1839 UTC

Plug a microphone into computer, place mic near sdr spkr.
Run mmsstv

Title: Re: AirSpy HF+ and SSTV decoding
Post by: MDK2 on March 31, 2018, 2017 UTC

Assuming you are running Windows, this is what you need:

https://www.vb-audio.com/Cable/

Now, the next link is specifically for installing and configuring a virtual audio cable to work with SDRuno. Obviously you're not going to be using SDRuno. However, it should help you out anyway because it is specific for this virtual audio cable.

https://www.sdrplay.com/docs/SDRuno_VAC.pdf  (PDF)

Once installed, you'll need to check the sound card settings in your SDR program of choice to make sure the audio is going OUT that way, and with any other app you use, be it MMSSTV, Fldigi, recording software including Bandicam or Audacity, make sure all of those have the virtual audio cable selected for the input.

Good luck.

Title: Re: AirSpy HF+ and SSTV decoding
Post by: Josh on April 01, 2018, 1955 UTC

You can also use the stereo mixer in windows to feed the audio to the app.

Title: Re: AirSpy HF+ and SSTV decoding
Post by: HulkSmash on April 01, 2018, 2010 UTC

Quote from: Josh on April 01, 2018, 1955 UTC

You can also use the stereo mixer in windows to feed the audio to the app.

How do you do this exactly? Do you just enable stereo mix and set it as the default device instead of the microphone?

Thanks!

-Mike

Title: Re: AirSpy HF+ and SSTV decoding
Post by: Josh on April 02, 2018, 1527 UTC

Quote from: HulkSmash on April 01, 2018, 2010 UTC

Quote from: Josh on April 01, 2018, 1955 UTC

You can also use the stereo mixer in windows to feed the audio to the app.

How do you do this exactly? Do you just enable stereo mix and set it as the default device instead of the microphone?

Thanks!

-Mike

Yep. Turn off any enhancements, amplificiation, eq, etc. No system sounds, but do give the app total control over the audio. Also make sure you run the sound card at its highest sample and bit rate on both input and output.

Keep in mind that vac will generally result in better decoding, but in a pinch, stereo mix works good enough and can feed about as many decoder apps as you want to fire up.

Title: Re: AirSpy HF+ and SSTV decoding
Post by: HulkSmash on April 03, 2018, 0004 UTC

Thanks!