QRQ'n CW on HF remotely in the QTH with a LAPTOP to a RASPBERRY PI - advanced setup for CW Keyboard, Paddles, & Straight Key

[Chuck aa0hw]

this is an advanced setup for remote control of an ELECRAFT K3S over ip on the LOCAL AREA NETWORK - a LINUX LAPTOP to the Rig's Raspberry PI's computer

AUDIO OVER IP: over the local LAN with routers and switches :
zita-njbridge is used to provide audio for RECEIVE AND TRANSMIT
https://kokkinizita.linuxaudio.org/linuxaudio/

ACTIVATING THE RIG's PTT with a 45 hertz SUB TONE:
before the CW AUDIO TONES arrive
using two GATES, the first gate(calf gate) sets an exact time for the SUB TONE to be "ON" ...then the output of the 1st gate activates a 2nd GATE(ZamGate) to shape the 45 hz SUB TONE with a very well shaped raised cosine edge, to prevent any harmonics or spurious, additional frequencies from getting to the RIG...so only a very pure 45 hertz tone reaches the RIG's LINE INPUT
https://calf-studio-gear.org/
http://www.zamaudio.com/

for this to work well, you have to experiment with the timings of the arriving CW AUDIO TONES to the RIG...using a LINEAR DELAY LINE
http://plugin.org.uk/ladspa-swh/docs/ladspa-swh.html#tth_sEc2.29
and adjust the CALF GATE RELEASE so that there are no CW audio glitches..which usually has to be done experimentally

BLOCKING the delayed RIG's sidetone monitor audio so that you only hear the local sidetone from your paddles, straight key etc...
DUCKA
http://openavproductions.com/doc/artyfx.html#ducka
NOTE: there is too much delay if you wait for the RIG's sidetone...so you monitor the paddles and any other morse code instrument locally in very low latency and BLOCK out the rig's sidetone

for the CW KEYBOARD, if you can tolerate @ 100 ms of delay from typing the letters until hearing the cw keyboard's sidetone, you won't have to worry about monitoring the CW KEYBOARD sidetone locally and can wait for the RIG's sidetone to reach your remote station

FLRIG to adjust the RIG's CONTROLS over ip:
http://www.w1hkj.com/flrig-help/

the REMOTE CW OP is using a LINUX LAPTOP with Lubuntu 16.04 -
using the KXstudio JACK APPS and with all the KXstudio LV2 plugins installed and available for use...
http://kxstudio.linuxaudio.org/
https://github.com/brummer10/jalv_select