SDR Sharp and Fldigi not talking

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sacentre
Posts: 28
Joined: Sun Feb 28, 2021 1:21 pm

SDR Sharp and Fldigi not talking

Post by sacentre » Thu Mar 11, 2021 5:14 am

Hi, I'm completely new to SDR and decoding but I hope someone suggest something I haven't tried yet to fix this problem. I'm waiting for membership approval of the Nbems group so I can ask there but meanwhile I thought I see if anyone here can assist.

I cannot get SDR Sharp to talk to Fldigi (or vice versa) via the free VB cable driver when trying to decode a simple RTTY 45/170 signal. There's no waterfall and only gibberish on the output screen. I have spent hours reading posts about this from others having similar problems but so far nothing has worked.

Re-installing SDR# and the VB driver as well as Fldigi didn't improve things. I also tried the trial version of VAC audio cable but got the same the same result. Obviously, I'm missing something.
At this point, I don't know if it's hardware or software that's causing the problem.

OS Windows Pro x64 (19042.844)
SDR# v1.0.0.1810
VB Cable Pack43
Fldigi v4.1.18

Thanks for reading.

tim_rtd
Posts: 180
Joined: Fri Jun 30, 2017 11:34 am

Re: SDR Sharp and Fldigi not talking

Post by tim_rtd » Fri Mar 12, 2021 9:49 pm

So you did configure what input you wanted to use in fldigi under configure , sound card, capture, selector., and on your sdr # audio output you selected the same line xx as virtual cable....make sure mute and squelch is off

sacentre
Posts: 28
Joined: Sun Feb 28, 2021 1:21 pm

Re: SDR Sharp and Fldigi not talking

Post by sacentre » Sat Mar 20, 2021 4:39 am

Hi Tim

I must have tried every combination of settings I can think of but still haven't hit on what I'm missing or doing wrong. Right now, I'm totally confused but will take a break and try again.

One respondent I talked to on another forum said I didn't need to use a virtual audio cable and that the sound card could be configured to talk to the decoder without it. That has confused me even more. Still, I'm hopeful something will come clear before long.

Thanks

Trevor

tim_rtd
Posts: 180
Joined: Fri Jun 30, 2017 11:34 am

Re: SDR Sharp and Fldigi not talking

Post by tim_rtd » Sat Mar 20, 2021 5:13 pm

Yes, that can be annoying having these issues. Just for fyi...I'm presently using VAC and fldigi ver 3.23.13 a1 successfully.
I started out using VB but couldn't get it to work. Then tried vac demo... worked for the 2 channels they give you. I ended buying it and now have 20 audio channels going.
I think I remember getting fldigi to work without any vcables, but I found I had to listen to audio too...
I just tried ver 4. The vac cable is working with it. The config setup is different than version 3 . I had some error launching it but it did after hitting the ignore button.
My only redundant remarks are make sure both vb and vac do not exist on your machine at the same time and enter your virtual cable in the sound card/device input of fldigi.

I have seen some unexplainable issues with v cables with my dsd. I still had to go into win sound setup and make my virtual cable the default input...

sacentre
Posts: 28
Joined: Sun Feb 28, 2021 1:21 pm

Re: SDR Sharp and Fldigi not talking

Post by sacentre » Sun Mar 21, 2021 10:42 am

Hi Tim
I just deleted an earlier reply to your post as it was no longer relevant. Since posting that I've managed to make progress on the decoding issue and you were right, it can be made to work without a VA cable. Also, I can listen to the signal at the same time which is the way I wanted it. You got me going in the right direction. Thank you! No I'm wondering under what circumstances one needs a VB cable in the first place.

I Googled on the question and found this link:-

https://sites.google.com/site/g4zfqradi ... qbe2pd24vi

which describes using the Stereo Mix function of the sound card (I've never had occasion to so much as look at that setting till today). Now here's the thing I find happens so often with PCs (and I have been working with PCs ever since the pre-Windows DOS days so consider my self no novice) THINGS CAN CHANGE ON THEIR OWN! :)

Like I said, I was trying to get the simple Black Cat WEFAX app working with a pre-recorded sound file just to prove it could work. I uninstalled and re-installed the software with all the defaults and changed no settings other than selecting the Stereo Mix Output/Input. Still nothing. After fooling around for a few hours unsuccessfully, I couldn't stand it anymore and went to take a nap.

Later, I did what most of us do in situations like this - tried it on another PC. I installed Black CAT on an HP tablet - again with all the defaults, played the sound file and down the screen began to scroll a FAX picture!

Conclusion: obviously there had to be something configured differently on my other PC. The hardware is different but I compared the settings one by one between the two machines and they were all the same - Stereo Mix (Default Device on Control Panel), Stereo Mix (Input Device on Black Cat). Then, just out of habit I hit play on the sound file and a FAX image started to appear! I have no explanation why. Deus Ex Machina? Elves? The tooth fairy?

The next step is to load up Fldigi, MMTTY etc and try those.

Sorry for the long ramble and thanks again for your help, Tim.

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