[Lowfer] newbie questions

[Rick Kunath]

Comments inline...

On Sunday, February 26, 2012 02:37:36 PM Bill Cromwell wrote:
> I'm new here looking at all sorts of things that are brand new to me. I
> ended up looking at a couple of new lists due to the upcoming new band
> at 600 meters. Here I see QRSS, WSPR, ARGO, Opera (the name of one of my
> web browsers BTW), Wolf and several others. I feel like a new aspiring
> ham studying for the novice exam! I'm wading through okay.

Yeah, why did the author pick a copyrighted name of one of the popular web 
browsers? I suspect at some point he'll be changing it. 

> I have a question or two for the list members. So far I have downloaded
> and played with a couple of the souncard packages. To date just looking
> them over and wading into the manuals for them. I have been successful
> at starting (no on air ops) running them in WINE on a Linux box.

Excellent. What distro, what WINE version, and Pulseaudio on the Linux box? Do 
you know about the Winetricks script, or have you needed it?

> This is
> NOT an OT question or statement about Linux v Windows. The fact is I run
> Linux. What I am more interested is what a minimum processor speed would
> be for some of these packages. I have found that Linux makes some of my
> older laptops more usable than newer versions of Windows. Some of the
> packages are not clear about minimum requirements - or I haven't yet
> found the specs. One package suggested it will run on a 400 MHz Pentium
> machine! I could use some suggestions about what has worked for others
> and what is just too dismally underpowered. I am interested in that
> because of the power budget for field operations. Faster always means
> higher battery drain. If older hardware is adequate I'm all about that.

Most of the apps run under WINE fine on an older P4 1.7 GHz laptop. But that 
all depends on how heavy the window manager is. You didn't specify your window 
manager of choice. (For the Windows folks, Linux users have a choice of GUI 
that runs on top of the OS. They can run any one of a number of different 
styled GUIs.)

> Looking at the speeds (SPEED?) of modes like QRSS I don't see them as
> useful for tactical communication in a large scale disaster but they
> could help the power budget for logistical and welfare traffic. I see
> they are also being used to "probe" propagation paths. That alone is
> worthwhile to me and I will try to get something up and listening as
> soon as I can. Are there other comments on how these slower speeds might
> be used. I can see that rag chewing is mostly off the table.

A few native Linux apps come to mind. Fldigi, for lots of sound card modes, 
and several Slow Hell (Hellschreiber) modes. Baudline, a good sound spectrum 
analyzer. Glfer, a dedicated LF analyzer with a lot of configurable features, 
not all that easy to find. It's old and needs to run in the PulseAudio padsp 
wrapper because it's written to use the OSS sound API which is no longer 
included in most distros.

But the rest of the apps will require running in WINE. As to OPERA, that I 
haven't tried in WINE. Later WINE versions do not access Pulse natively. The 
devels broke a hack that was available which used a plugin. However, WINE 
still works using the Pulse ALSA plugin.

The thing is to make sure that the Pulseaudio default sample rate is at your 
sound card's native rate. It's usually set to 44100 Hz but some sound cards 
have a 48000 Hz sampling rate. The conversion is cleaner if you set Pulse to 
use the native rate. Also, the accuracy of any PulseAudio re-sampling can be 
configured too. You can dial it up if you need to, recognizing that the CPU 
usage will rise a little if you do. 

Hope that gives you some ideas.

Rick Kunath