Probably the easiest service to monitor is the US Coast Guard. The Coast Guard use VHF marine frequencies available on all but the most basic scanners as well as short wave frequencies making them easy to monitor almost everywhere. They also sometimes use the UHF airband frequency, plus government land mobile frequencies. The Coast Guard operates 46 Group and two Section offices whos responsibility includes listening to distress calls over VHF maritime channel 16 (156.800 MHz). Approximately 20,000 to 25,000 distress calls are made over this system each year. On the Pacific, Atlantic, and Gulf coasts, these stations also listen for distress calls over the international radiotelephone distress frequency of 2182 KHz. These Group and Section offices also make voice broadcasts of wheather and navigational warnings over VHF channel 22A (157.100 MHz and 2760 KHz). You dont need to live near the ocean to hear Coast Guard action. If you do live withen 20 miles or so (with a good outside antenna) of a major lake, river, or other water way, program........156.800, 157.050, and 157.100 MHz......into your scanner's memory banks. The first frequency 156.800 (CH 16), is the international hailing and distress frequency, the frequency 157.050 (CH. 21) is a Coast Guard working frequency. The third 157.100 (CH. 22A) is a Coast Guard public liaison channel. Marine warnings and weather are broadcast on this channel. Note that when listening to VHF Coast Guard frequencies a condition known as tropho ducting can cause you to hear these stations up to hundreds of miles away. And is common durring the summer months.
If you dont live near major lakes or oceans than it's time to get out the old shortwave radio. Tune to: 5.696 MHz upper sideband.
This is one of the two primary Coast Guard aviation search and rescue frequencies ( the other is: 8.983 MHz upper sideband).
Communication here can be heard thousands of miles away. The frequency: 2.182 MHz is used for hailing and distress. There are
many other frequencies used but this will get you started.
GLOBAL HIGH FREQUENCY SYSTEM (all in USB) 4.724 6.739 8.968 8.992 11.175 13.200 15.016 17.976
Another good place to monitor military aircraft is on the VHF civilian aero band. From 118.00 to 137.00 MHz. All but the most basic of scanners covers this band. Probably the best place to look for frequencies for your local airport or military airfield is the airnav web site
Some of the most exiting military monitoring is the air-to-air and tactical communications found in the 138.00 to 144.00 MHz range of the land mobile band. You could hear practice missions of aerial combat manuevers. You will need to be able to set your scanner to AM mode to receive the aircraft, make sure when buying a radio it has manually adjustable receive modes.
New trunked systems are being installed at many military bases, but with only 5-10 active frequencies, and just a handfull of users, they are much easier to monitor
than large civilian public safty trunked systems. Many large Navy vessels also have trunked systems.
USAF BASE SUPPORT TRUNKED RADIO SYSTEM FREQUENCIES 406.3500 Group 1 Trunk 407.1500 Group 1 Trunk 407.9500 Group 1 Trunk 408.7500 Group 1 Trunk 409.5500 Group 1 Trunk 406.7500 Group 2 Trunk 407.5500 Group 2 Trunk 408.3500 Group 2 Trunk 409.1500 Group 2 Trunk 409.9500 Group 2 Trunk 406.5500 Group 3 Trunk 407.3500 Group 3 Trunk 408.1500 Group 3 Trunk 408.9500 Group 3 Trunk 409.7500 Group 3 Trunk 406.9500 Group 4 Trunk 407.7500 Group 4 Trunk 408.5500 Group 4 Trunk 409.3500 Group 4 Trunk 410.1500 Group 4 Trunk
