[Elecraft] Free DV (digital voice as reported in QST-April issue)

[Richard Fjeld]

Eric,

The K3 interfaces easily for freeDV, and I have had several unsolicited audio reports that said I sounded very natural.  Unfortunately, we can't use our DVR for this. 

You use freeDV like you do for psk31, but with the addition of either a USB sound dongle to plug a computer headset/mic into, or you use a USB headset/mic.  I had a cheap computer headset/mic, so I use a USB sound dongle.  They are as cheap as $1.69.  Either one will look like another sound card to your computer.

There are a couple links on the website for YouTube videos that are very good tutorials.  I suggest you watch them and pause them as needed while you are setting up your audio configurations.

Keep your power down to approximately one forth of your output capability.  The last recommendation I read was 20 %.  My first qso happened while I was testing at 5 watts.  The other station was a VE3, and I live in western MN.  It doesn't take much signal strength, just enough to be above the noise level.  I have watched strong signals that were being 'distorted' by band conditions such that the SNR dropped to near zero and a loss of sync was experienced.  At no time did the strong signal itself fade.  (That was before 0.961 version.)  My point is; a strong signal is no guarantee.  If a signal can be decoded, the audio will be as loud as the computer is set for, no matter what the signal strength is.

So far, I have not used Data A, but I have used the appropriate sideband so that I could hit the 'analog' button and speak to the other station using SSB as needed. 

Some people experience a delayed echo of about 2 seconds while transmitting.  If so, you may need to turn your audio monitor off.  A USB sound dongle has a mute button for the phones that may work for this.  (Mine does not. Mine is an iMic.) You may need to unplug the radio's mic if needed.

You will need to experiment by testing which sound card sliders do what, and how they should be set.  Start out low, say one forth up.  You can use Quickmix, or Romac software to save your settings if wanted.  Keep your ALC low, just barely visible.  Make notes.

Good luck,

Rich, n0ce



  ----- Original Message ----- 
  From: Eric Lanzl 
  To: elecraft at mailman.qth.net 
  Sent: Tuesday, April 02, 2013 6:52 PM
  Subject: [Elecraft] Free DV (digital voice as reported in QST-April issue)


  I am wondering how to set up the k3 for the Free DV (digital voice) the article 
  in QST about a way to do digital voice on hf. Has anyone tried it with the k3? 
  Would one set the k3 to the DATA A position? How does one set the audio on the 
  computer sound card? I am very new to the digital modes and do not fully 
  understand what the settings mean. Can someone run through how to set the k3 for 
  Free DV. I think you also have to set the line out setting in the config menu 
  and hook up the line in line out cables to the computer. Can one use a regular 
  computer mic and headphones. I know the Free DV article calls for a USB headset. 
  I have a headset but not a usb headset. It uses the mic and speaker jacks on the 
  computer. Will this work as well as the usb headset?

  Thank you very much
  Eric