Glad that it worked. Maybe a good time to start?
I'm a cold war boy used to code in plain C language on embedded systems, with good memories for Z80 & 80C31 & AD2101DSP assembler works till the middle of 90s :-)
But i love NI Labview on PC side ;-)
With the straight coax RG58 cable i have more consistent calibration results against Rigol probe reading .... but i wonder why ...
Strange ... How did you connect the probes on the HDG? In fact I don't use the RIGOL probes that came with my DSO. I stick to the Metrix HA1316 probes I had and that I like a lot: 2 settings points (1khz+1Mhz) plus convenient accessories (BNC plug adapter, ...).
At least did it solve the HDG selftest problem?
HDG selftest errors disappeared already from the first manual calibration.
Calibrating with the Rigol probe leads to high DC offset and HF amplitude attenuation (the probe reads higher HF amplitude than straight cable), i will try a different scope probe later.
Anyway i just noticed a DS1074 problem :
with one channel in use fine trimming the vertical sensitivity to 335mV/div or less (channel set to 1X), signals over about 30Mhz becomes significantly distorted at least on the screen.
I saw that during script calibration and i checked it manually after, discovering also that if you enable other channels the distortion disappear
See the attached screenshots, 2Vpp sine 90Mhz signal, 340mV/div (signal good), 335mV/div (signal distorted one channel in use), 335mV/div (signal good two channel in use), all with coax cable and 1X probe ratio.