The official Thunderbirds website is http://www.airforce.com/thunderbirds/

Radio Frequencies
DescriptionFrequency
Air to Air140.0000
Air to Air140.4000
Air to Air141.8500
Air to Air143.8500
Maintenance148.5500
Air to Air Solos (5-6)236.5500
Air to Air236.6000
Air to Air Solos (5-6)241.4000
Team Leader Command250.8500
Air to Air Solos (5-6)273.5000
Air to Air Solos (5-6)283.5000
Air to Air322.3000
Air to Air322.6000
Air to Air Tactical382.9000
Air to Air Tactical394.0000
Ground Support413.0250
Ground Support413.1000
Ground Support413.1500
Ground Support413.2750
Ground Support413.3500
Ground Support413.4000