Hawker 900
Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Commercial
Flight Crew Last 90 Days 80; Flight Crew Total 5000; Flight Crew Type 2500
Troubleshooting; Communication Breakdown; Distraction
Aircraft Equipment Problem Critical
Air Traffic Control Provided Assistance; Flight Crew Overcame Equipment Problem
Aircraft
Reaching the boundary with US airspace Between Country 1 and US I was monitoring the frequency with Country 1. I then heard Country 2 Accent; I found that odd due to the fact that we were with Country 1. I asked my First Officer if he had swapped back to Country 2 Control for some reason. I switched back to Country 1's frequency and tried to check in again to make sure they were not calling us. My com 1 screen was not working and com two did not allow us to out any frequency. I could put the frequency on standby; moved it to active but then it would go back to a frequency XXX.XX. I was able to communicate with them which was ZZZ Airport. I mentioned what was going on; my location and if he could relay a message with ZZZ1 Center. I recall he gave a couple frequencies for me to contact but was not able. I asked for a landline number to be able to call from the sat phone on board. By this time the radio kept swapping frequencies automatically and I lost contact with ZZZ Airport. I squawked 7600 [and] brief my copilot and passengers and began our descent to follow our loss on comms procedure. On the descent I was able to get a hold of ZZZ1 Center and was instructed on heading and altitudes. Reaching ZZZ2; ZZZ1 Gave me another number to call which was Approach and that they would be the one to guide me and give me landing clearance. In the meantime I was being vector i believe 11;000 feet and 190 on the heading. Once I got a hold of Approach on the phone we were instructed and landed without an issue. I contacted our repair station and both radios were bad.  Both radios have been replaced.
Captain reported communication system failure and having to use a satellite phone to continue with the flight.