Hi folks,
since fenths i change my old converter for audiosignals to an ETM-Digi1
with optocoupler, transformer, stored in an tin box. So it seems to be
immune against radiation of cabling, trx and so on.
But since this change in my configuration i get temporary errors of wsjtx.
The detailed information tells me this:

Hamlib error: Communication bus error
rig_get_freq(1914): freqMainB=21074000, modeMainB=AM, widthMainB=2400
rig_get_freq: elapsed=5420ms
rig.c(1917):rig_get_freq return(-13) Communication bus error
rig_get_freq(1914): freqMainB=21074000, modeMainB=AM, widthMainB=2400
rig_get_freq: elapsed=5420ms
rig_get_freq: elapsed=5420ms while getting current VFO frequency

The error only occurs on 10m, 15m, 80m, 160m, is no problem at all,
everything works fine, especially
PTT activating and CAT control of my Icom 706. With my old Alinco DX70
the same error occured, so i'm sure,
that the rig is not causing this trouble.
I also changed the ETM-Digi Box with a newer one, i replaced the USB
to serial adapter, i've
put tinfoil around the whole equipment and connected it to the
heatpipes, grounded
in the basement of my house.

Even the raspberry has been changed but the effect is the same.
When disconnecting and reconnecting the USB2serial to its USB port,
everything works fine
unless next crash with the same error report.

The error announces, when sending in FT8 breaks, PTT goes off and RIG
switches to another mode shorty,
so it seems to get kinda CAT reset or so. But why?

So i'm at one's wits' end now and hope, you've got some good ideas for
a solution.

Thanks and cheers

Cornel