I'm sure you've looked, but could it be a US Ft vs Int Ft thing?
Good question, but we aren't even at the XY stage, strictly trying to get the Lat, Longs to mesh.
The usual solution is to run a site configuration against your control points
Either you check in and configure (localize), or you have nothing
"Basically, they don’t understand the equipment and I don’t have hands on access to it."
There's your problem! 🙃
I saw something similar once. I was testing a rental unit. R12i tsc7. It was off several feet using rtx vs what I knew was about the right nad83(2011) value I had from VRs and an opus solution. I didn’t dive to much into it but the rental dc I swapped same r12i and it was no longer off but a tenth or so on the ground. I chalked it up to a software glitch in that version of Trimble access. We had the latest at the time and the rental was a few versions behind. Not saying that’s it but coordinate system managers often need updates.
I did a quick check in the help menu online for Trimble access. Two things caught my eye. One is that it seems you can apply a rtx rtk offset between frames of itrf and rtk data so that might be a setting causing the issue. The other I saw was rtx is in a ITRF 2005 epoch only. Now I didn’t read all of everything just thought if you had a chance to read up on that or the users it might shed some light on the issue.
Got it, the surveyor for my client (PE) stopped by the office with his DC and R12i. We were able to set-up in his controller a state plane RTX job with a ITRF to NAD83 setting. We can also do a local site scale factor so there are ground coordinates on their system. We did a second set up for our office control points and checked it RTX and it was the expected .2' from the NAD83(93) position.
Easy peasey, I only needed to get my hands on his stuff. He is going out this afternoon and test out the set-up,,,,,,,,,,no need for a calibration.
Why did you setup control points for someone who was not going to use it, just check into it, while using different control (base station data)? 🤔