Acquired site with functioning business radio system - need to program more radios.. any tips?

Hi all,

I’ve always been interested in learning about getting started in 2 way radio as a hobby, now “WORK” is allowing me to learn at their expense. My work has purchased a site that has a few functional Motorola XPR3500 radios that talk to each other. The company that owned the site previously was publicly traded, so in most cases no expenses were spared at the time (10-15 years ago).

There are a couple buildings and I think we have 2 Motorola XPR 8400 repeater/base stations with antennas on the roof.

We have a few Motorola XPR3500 handhelds that work and can communicate with each other, so those are fine.

We also have a few Motrola “XTN” and Vertex Standard 427’s that power on, but don’t appear to be on the same channels or anything we can hear between themselves or the XPR3500’s.

We don’t have passwords (if there are any) to anything like the repeater/base station or any of the radios that I know of.

Do I just need to get programming cables and software for the Motorolas and Vertex and then read the programmed frequency from the XPR3500’s and use the same on the other 2 radio models?

I’m fairly tech savvy so the programming parts I’m afraid of learning. I’m more concerned if there are any legal / FCC requirements in transferring or re-registering the business class base station or frequency(ies) from previous owner to the new owner or anything like that before I attempt to program anything.

Any tips for a motivated and equiped 2-way newbie would be greatly appreciated.