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Technical Topics => SDR - Software Defined Radio => Topic started by: raypfaff on March 11, 2021, 1538 UTC

Title: Bad SSTV... and MFSK64, 32, and Easypal
Post by: raypfaff on March 11, 2021, 1538 UTC
I'm hoping someone here might have an idea as to what's causing this, cause I'm about to pull what little hair I have out.  I use a Windows 10 box with Easypal, MMSSTV, and Fldigi on it.  I route audio from my IC-R75 to the Windows box.  Sometimes I listen to KiwiSDR on another computer and route audio from that to the Windows box when propagation isn't good here.   This has worked fine for at least 3 months, probably more.  Last Wednesday I was listening to an MSFK64 transmission and it was perfectly fine.  On Thursday, I picked one up and the image was corrupted like below.  Since that time, all images I get through KiwiSDR are corrupt (SSTV, MFSK, and possibly Easypal), but the images I pick up through the Icom radio are perfectly fine.  Images look like this Scottie 2:
Interesting to note that MMSSTV still identifies the image as Scottie 2.  Likewise, it will switch modes properly in Fldigi.  I've ruled out the Windows 10 box and the audio cable because connecting it to my Icom results in perfectly fine images.  So...'something' changed on my Windows 8.1 box that I'm running Chrome on to use the Kiwi WebSDR app, but I can't figure out what.  Looked at the audio and it's the default 24 bit 48000 hz sample rate.  I tried using both the front and the back line outs.  When I listen to the audio, it sounds perfectly fine to me.  I've not made any upgrades.  Does anyone have any ideas or suggestions?
Title: Re: Bad SSTV... and MFSK64, 32, and Easypal
Post by: raypfaff on March 12, 2021, 1332 UTC
Hmmmm, problem solved.  I accidentally did two things at once, so I'm not exactly sure which fixed it.  Or it just decided to work again.  This morning I was pulling a splitter off of the rear audio line and I accidentally plugged it into the wrong output.  Also, I know that Chrome is a bit weird with audio, so I switched over to Firefox.  Either way, I caught Shortwave Radiogram this morning on 15770 and was able to correctly decode it's MFSK64 images.