34.900   Used nationwide by the National Guard during emergencies.
39.460   Used for inter-department emergency communications by local and 
         state police forces.
47.420   Used across the United States by the Red Cross for relief operations.
52.525   Calling frequency used by ham radio operators in FM on the six-meter 
         band. During periods of exceptional propagation, this frequency is 
         filled with signals from hundreds or even thousands of miles away. 
         If you're hearing distant signals here, then the 30 to 50 MHz range 
         is also open for long distance reception.
121.500  International aeronautical emergency frequency.
138.225  Prime disaster relief operations channel used by the Federal 
         Emergency Management Agency (FEMA); it is active during earthquakes, 
         hurricanes, floods, and other catastrophic events.
146.520  Used by ham radio operators for non-repeater communications on the 
         two-meter band; it is very busy in many parts of the country.
151.625  Used by "itinerant" businesses, or those that travel about the 
         country. Circuses, exhibitions, trade shows, and sports teams are 
         some of the users you can hear. Other widely used itinerant channels 
         are 154.57 and 154.60.  
154.280  Used for inter-department emergency communications by local fire 
         departments; 154.265 and 154.295 also used.
155.160  Used for inter-department emergency communications by local and 
         state agencies during search and rescue operations.
155.475  Used for inter-department emergency communications by local and 
         state police forces.
156.750  Used internationally for broadcasts of maritime weather alerts.
156.800  International maritime distress, calling, and safety channel. 
         All ships must monitor this frequency while at sea. It is also 
         heavily used on rivers, lakes, etc.
162.400  Used for NOAA weather broadcasts and bulletins.
162.425  Used for NOAA weather broadcasts and bulletins.
162.450  Used for NOAA weather broadcasts and bulletins.
162.475  Used for NOAA weather broadcasts and bulletins.
162.500  Used for NOAA weather broadcasts and bulletins.
162.525  Used for NOAA weather broadcasts and bulletins.
162.550  Used for NOAA weather broadcasts and bulletins.
163.275  Used for NOAA weather broadcasts and bulletins.
163.4875 Used nationwide by the National Guard during emergencies.
163.5125 National disaster preparedness frequency used jointly by the 
         armed forces.
164.500  National communications channel for the Department of Housing 
         and Urban Development.
165.375  National communications channel for the Secret Service.
166.4625 Used nationwide by federal law enforcement agencies, including 
         Customs, Secret Service, and the Bureau of Alcohol, Tobacco, 
         and Firearms.
167.5625 National communications channel for the Federal Bureau of 
         Investigation.
168.550  National channel used by civilian agencies of the federal government 
         for communications during emergencies and disasters.
243.000  Used during military aviation emergencies.
259.700  Used by the Space Shuttle during re-entry and landing.
296.800  Used by the Space Shuttle during re-entry and landing.
311.000  Active in-flight channel used by the U.S. Air Force.
317.700  Active channel used by U.S. Coast Guard aviation.
317.800  Active channel used by U.S. Coast Guard aviation.
319.400  Active in-flight channel used by the U.S. Air Force.
340.200  Active channel used by U.S. Navy aviators.
409.200  National communications channel for the Interstate Commerce 
         Commission.
409.625  National communications channel for the Department of State.
415.700  Used nationwide by various federal agencies.
462.675  Used for emergency communications and traveler assistance in the 
         General Mobile Radio Service.