No problem!Thanks for the good information, nonperson! Your reply snuck in between when I was writing my reply.
So, am I understanding correctly that there is a difference, after the mode change, in VFO frequency accessibility? And, that it requires programming software to store some of the frequency ranges that the amateur model can store through the VFO keypad?
The only difference I noticed is mode 4 which has a wider frequency span for the 500TB. In mode four I could manually enter any frequency through the key pad and the VFO / channel selector. I just couldn't program or read it using the software when it was in mode 4 with the setup I have. Maybe someone else will have better luck with it.
In the other modes I could program it manually or with the software with no problem.
FWIW I got mine from MTC who posted on their website that the radio would be shipped "locked" and a cable and software would be needed to unlock it. I got the radio before I got the RT Systems cable and software. While waiting for the cable to arrive I found this thread and tried the keypad unlock method posted earlier. The first time it didn't work when I put it in mode 1. I tried the other three modes then went back to mode 1 which allowed me to use it in mode 1.