Email requesting the cap spec sent to Siglent. Now we wait.
Thanks a lot!
VC3 and VC4 have ~30 pF adjustment range and with C*115 in parallel I measure ~18-48 pF.
My SMD tweezers checked against the 4 pF caps Siglent sent me reads ~4 pF high.
So my best guess for C*115 value is 12-18 pF with seemingly enough adjustment in VC3 and VC4 to cover any of my measurement errors but no allowance for minimum VC* value.
So 12-18 pF will be max value for C*115.
C*115 removal and retest will the only way to get a closer value.
No reply from Siglent yet.