That is pretty good analysis of what maybe happening.
I have not noticed the "saver" posts the port baud rate.
Even if the baud rate is on borderline of the system ability the
RS232 protocol should be able to control the its data flow.
Here are some other details I did observe
I can set the sweep bottom / top to 400 to 500 MHz and run it.
I can observe expected graphs.
I can ":narrow down the sweep" - 440 to 450 MHz and still see expected results.
but when I set 445 to 448 MHz with "frequency of interest " in that range , I get garbage.
When I go back to 400 to 500 MHz I still get garbage
until
I start over with 100 to 500MHz. sweep .....
