I am posting this info to the JTDX forum as well as Expert-Electronics.

After the release of the new JTDX I was excited to be able to use the TCI connection to ExpertSDR for the audio connection. But unfortunately this did not work on my Arch Linux computer, because I had many dropouts and crackles in the transmit signal, like before with a bad connection via audio loop.

After many unsuccessful experiments I tried to see what happens if I delay the network loopback interface (lo).

$ sudo tc qdisc add dev lo root netem delay 5ms

Unexpectedly, the two programs suddenly work together without any problems, no more dropouts, no more crashes.
I don't have an explanation for this yet, but wanted to pass along the tip in case other OMs have similar problems with it.

Furthermore, it has shown to be favorable in my case, to increase the parameter of
ExpertSDR / Options / Device / TX / Tx to Rx to 300 ms
because otherwise there are shifts in the transmission from pass to pass.

73 de Dieter, DK6OV

I have tested lz2hv.org/node/10 (MSHV) on windows using TCI for CAT and audio. Seems to work ok. There's a glitch in audio TX when switching between programs i.e using alt+tab

I'll check MSHV on Linux later this week to see if this works ok. Have been using JTDX on Linux with TCI but i had more success with MSHV but this is probably due to that i have not been testing TCI via JTDX very long.

73 de LA3QMA

I have looked into the loopback interface again and have now probably found the reason for the problem and an even better solution. The following command must be executed before starting ESSR2 and JTDX.

$sudo tc qdisc add dev lo root tbf rate 1000mbit burst 66kb latency 400ms

This command limits the burst mode to the size of the mtu. This stops sending huge packet blocks from one program to another. I have worked with it now quite a number of FT8 and FT4 QSOs and was pleased about good connections and surprisingly good rapports.

There may be something more. Occasionally after a start of the programs dropouts occurred again. Then SDR and PC had to be rebooted and the above command had to be executed again.

73 de Dieter, DK6OV