National Calling Frequencies are used mainly by Ham operators, somewhat like the truckers use Channel 19 as a meeting place.
Since Hams have thousands of frequencies to choose from it would be next to impossible to know what frequency to call one another on, especially when they are away from there home base. So each band has one or two frequencies they use to make an initial contact. Once a contact is made they normally move to another frequency to talk so the Nat'l frequency is available for someone else.
Some of these calling frequencies are asigned for CW (Morse Code) so all you will hear are the dots and dashes as they communicate.
Fred KS1USA
Yes, there are calling frequencies in each band, VHF Low, VHF High, UHF, 700 and 800 MHz. Since the federal government does not operate above 406-420 MHz they only have calling frequencies on VHF and UHF. When new federal frequencies became available following the 2005 narrowband mandate for the federal government, four additional interagency calling frequencies were allocated: 163.7125, 167.1375, 168.6125 and 173.6250. The use of these is open for temporary and itinerant use by any agency with no one agency having priority over other agencies. This is the same situation that 163.100 and 168.350 has had for many years.
The NTIA Redbook of 2005 indicated that the new narrowband frequencies listed above were to replace 163.100 and 168.350. These frequencies were to be used exclusively for portable and itinerant repeaters with 163.100 being the repeater output. I've noticed that more than 6 years later, simplex use of the two is still occurring. I'm not sure why.
The federal and federal-non federal interoperability plan has many calling channels, again in each band.
