Re: It was "fine", then... strange behavior #draws #setup #betaimage

Gayland Gump

I haven't the sophisticated knowledge of how the DRAWS & UDRC perform their magic but I have the following observations.  

Out of the box, the DRAWS would not work with my Yaesu 857D when running fldigi. I believe that the PTT wasn't working immediately after I did the initial configuration of fldigi but I can't be sure.  Thinking back a couple years or so when I first got my first UDRC I began to suspect the ALSA settings.  Examining the UDRC settings and comparing them to the DRAWS I tried changing a couple of the parameters on the DRAWS to correspond to those on the UDRC.  After a couple changing a single parameter at a time with no change in outcome.  

I realized that on the UDRC I had the on board audio turned on.  In order to model the working UDRC, I decided to activate the onboard audio using the "dtparam=audio=on" parameter in the /boot/config.txt file on the DRAWS.  I had no definite rationale for doing this other than to eliminate another difference in the UDRC and DRAWS configurations.  The impact of making that change in situ on the DRAWS was disastrous as on a reboot the system was entirely un-useable.  I immediately reversed that change and returned to pursuing the ALSA settings.

As my earlier approach of changing single ALSA parameters had not yielded any change in fldigi's performance, I did a wholesale change of the DRAWS alsa settings to those that were currently in place on my working UDRC.  After completing these changes, the DRAWS was able to transmit and receive.  There are still some issues though.

First, there is a significant difference in SNR reports on the UDRC vs the DRAWS.  DRAWS levels appear to be 10 or more DB lower than those being reported by fldigi on the UDRC.  As all I do to obtain these observations  is move the 6-pin DIN connector back and forth between the UDRC and DRAWS using identical ALSA settings, I'd like to know what might be causing the differences in the SNR reports between those devices.

Another difference, which I note between the DRAWS and UDRC which may well be related to the level differences is in the fldigi waterfall display.  To the best of my knowledge the applicable waterfall settings on the DRAWS and the UDRC but the displays are significantly different.   I've got my UDRC set so that the waterfall shows a constant noise level.  Lots of others seem to prefer having a noiseless screen that only display's stronger signals.  I find that by leaving the display set so that it displays noise I am able to visually identify some weak FSQ signal patterns.  

I'd also like to know what it takes to get the on board audio working on the DRAWS after all some of the software running on the DRAWS provides audio cues that it might be nice to use.  Of course assuming that those cues can be delivered to the on board audio for presentation.

I want to applaud all of NWDR's efforts at bringing us some very cool and useful tools.  I also recognize that providing documentary support for these tool is extremely challenging given the resources available.   Given the constraints, I know that it is a lot to expect that NDWR keep in mind that we users including early adopters often don't have the necessary depth of knowledge that NDWR folks have and expecting us to know about non-standard applications (e.g. chrony vs ntp) or even basic linux system operations need to be carefully considered assumptions.

Finally, I'd like to find out if NWDR has any ideas why I'd be seeing the differences in SNR that appear between the DRAWS and UDRC?  What have I overlooked or just don't know about?

Thanks again for your time and attention.


On Wed, Dec 19, 2018 at 7:07 AM Jack Spitznagel <kd4iz@...> wrote:
Basil, John, All,

Initially, Beta 5 seemed to work out of the box but I ran into some DRAWS audio and keying strangeness that is baffling me after 3 tries at installing from newly flashed microSD cards and following Basil's latest procedure on GitHub. Hope you can provide insight. Rig is a CAT controlled IC-7000.

Tested Direwolf with Xastir and YAAC with both RX and TX successfully, but noticed the audio was a bit hot - signal here looked normal on the SpecLab so I left it alone.

Then disabled AX.25/direwolf (script) and configured fldigi and wsjt-x. Both programs worked in receive but the TX audio to the IC-7000 was very "hot". Put fldigi in tune then to bring the ALC reading as close to zero as possible by reducing audio levels with the PCM drive control. As audio level is reduced - the ALC starts to "pump", as did the power out indication - unexpectedly, there was a increase of noise on audio and harmonic spikes got higher as level of signal was reduced. Returned levels to where they had been and meter indications returned to where they were before. Was able to have a PSK31 QSO and got no comment about the signal quality.

I re-enabled AX.25/Direwolf using the script. Now both Xastir and YAAC no longer would transmit audio. When the rig is keyed, the TX LED on the rig flashes 3-4 times quickly and there is no modulation of the FM carrier. Reboot did not change behavior. Going back to non-AX25 mode, now fldigi would key the radio, but  no modulation occurred.

Re-installation of the DRAWS beta 5 from the ground up (x2) did not help - none of the programs transmit audio and symptoms are the same.

To be sure rig was OK, I hooked up an old SIgnaLink to a laptop, ran HRD and it drove and keyed the rig just fine. So I have to assume that the problem is software or DRAWS hardware related.

Where should I be looking to fix the audio? The keying?
Settings should not so brittle. Thanks in advance,
J Spitznagel - KD4IZ
Science River LLC

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