I have a Topcon Hiper Pro unit (Specs say: Internal Tx/Rx UHF (Selectable frequency range)), which I currently use only as a Network Rover. The Hiper Pro could be used as an RTK base or Rover.
I'm considering getting a Spectra Precision unit (Maybe a ProMark 800, which has an optional radio: Pacific Crest UHF Radio (Rx) 430 to 450 MHz & 450 to 470 MHz). If I paid more for the radio unit, could I do a base/rover set-up with the Topcon? I'd assume they'd talk to each other as long the spectrum ranges can be paired-up.
I ran a Trimble 5700 base with a TDL450 Radio and two Javad Triumph 1 rovers earlier this year with no problems. I dont see a problem as long as the Base/Rover can speak the same language.
The receiver would work as a base for a new rover. The radio may not. If it is an older 25kHZ bandwidth radio, it would not be legal to use. If it a newer digital UHF with updated firmware it could work. Also you could add an external(and higher power) ADL radio at the base and it would 100% work as a base for a new rover. I would highly suggest considering a SP80 over the 800 should you decide to upgrade. I would happy to assist you directly if you would like. I am a Spectra and Topcon dealer.