Maybe I could help... I can read & speak Russian.
Apparently Vladimir is getting full output out the low-level jack. This happened to me too.
The problem went away when I clicked on the "Enable PA" in the setup for Thetis.
There is a pair of analog switches that route the differential transmit signal EITHER to the low-level jack OR to the PA. Never
both.
So if there is output at the low level jack, those switches are set wrong.
At this point, I would consult the schematic, get out a scope and verify the control signal to those analog switches. The signal
is called "n1" and it comes right out of the FPGA.
Here's the schematic:
- Jerry, KF6VB