Notes for doing digi mode with traditional transceiver and linux

using the well-hated pulseaudio

rig: yaesu ft-857d
pc: ubuntu 14.04 lts on Asrock Extreme4 having hd-audio+ALC898: multichannel analog out, SPDIF stereo output, 3 inputs (line/rear mic/front mic)

Cable: simple in/out cable between line out/line in of PC and the rig's DATA port. No need to convert levels with ft-857d.
TODO ramble about isolation
FT-857D DATA 1200 OUT - PC line in (i soldered left and right inputs together)
FT-867D DATA IN - PC line out (using only left channel, tip on the jack)
GND - GND doh
Connector on rig side: 6 pin mini-din https://hqelektronika.hu/termekek/mdc-006-6p-mini-din-lengo-dugo-ps2 HQ elektronika and TME id MDC-006

using both outputs (analog and SPDIF) to separate usual sound from audio going to the rig

pulseaudio with default configuration can not use both analog and SPDIF output at the same time.
Need to create a new pulseaudio profile and assign it to the sound card with udev following this:
I copied /usr/share/pulseaudio/alsa-mixer/profile-sets to 2I4Ospdif.conf and found at the end:

; An example for defining multiple-sink profiles
#[Profile output:analog-stereo+output:iec958-stereo+input:analog-stereo]
#description = Foobar
#output-mappings = analog-stereo iec958-stereo
#input-mappings = analog-stereo

The example is exactly what we need just commented out. So rewrote it:

; An example for defining multiple-sink profiles
[Profile output:analog-stereo+output:iec958-stereo+input:analog-stereo]
description = 2 In 4 Out with spdif
output-mappings = analog-stereo iec958-stereo
input-mappings = analog-stereo

Description of profiles and other things in this file is at the top of this same file.

Most of the files are descriptions of single inputs and outputs (but one kind of input and output combined into a single entry). A profile is a combination (a list) of inputs and outputst that will show up as sinks and sources (in pavucontrol). There are no profiles specified in the default file because pulse audio does something called auto profiles which takes every possible combination of inputs and outputs (which were described above in the profile file) and if alsa has a pcm for it then the autogenerated profile becomes available in pavucontrol Configuration tab. It only considers 1 input, 1 output (short: 1+1), 1+0 and 0+1 combinations so I had to make a profile manually for 2 output and 1 input.

Associating the new 2I4Ospdif.conf with the sound card.


SUBSYSTEM!="sound", GOTO="pulseaudio_end"
ACTION!="change", GOTO="pulseaudio_end"
KERNEL!="card*", GOTO="pulseaudio_end"

ATTRS{vendor}=="0x8086", ENV{PULSE_PROFILE_SET}="2I4Ospdif.conf"


I only have one Intel sound card in my PC (the integrated one) so I went with matching only teh vendor.

signal levels, VOX

857D settings:

I use alsamixer for setting signal levels on the pc. Watch out for pulseaudio sometimes overrides the setings you made with alsamixer! For example when accidentally changing signal levels in pavucontrol and whan wsjtx starts up (meh), it changes alsamixer Capture settings.

When I set input signal level with pavucontrol it seems to distribute gain between Line Boost and Capture mixer elements. This does not look good to me so I keep using alsamixer.

Signal level of output from PC must be set so that ALC display on ft-857d is below the mark (a little longer horizontal line that is only visible when ALC level reaches it). ALC response is getting very sensitive to changing output signal level in alsamixer. If it's too low DIG VOX will not trigger.

Actual proper output signal level gives NO ALC indication. It's hard to accomplish this and keep vox working.
One solution is using CAT for PTT (and freq) control but it seems this could increase noise on some bands.
It may be worth trying PTT with a serial port control line (and give up CAT).

Always keep pavucontrol (and alsamixer) running. Otherwise output of wsjtx may switch to the wrong output device. meh.

Periodically check and readjust output level. Increase it until ALC indication starts to appear then decrease one step. Best output signal is maximum signal that gives NO ALC!

TODO pc input signal level

TODO sample rate ramblings

TODO experiment with pasuspender :)

jack retasking (to be used later on my notebook with a single combo jack)

apt-get install alsa-tools-gui
hdajackretask gui app

Contributors to this page: dnet and jazzkutya .
Page last modified on Tuesday 11 of October, 2016 10:28:40 CEST by dnet.

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