Comprehensive Information About Natural Resource Agency Tone Use
It is important to note that on the Tonto National Forest the input and output tones for a given repeater are different. There are a number of ways a National Forest use tone for their repeaters. All repeaters require a tone to key up a repeater and of course each repeater has its own tone. On some very large National Forests a tone might be used more than once due to topography and distance. Such is the case on the Los Padres (California) and Humboldt-Toiyabe (Nevada) National Forests. These input tones are usually from the following set:
Tone 1 110.9
Tone 2 123.0
Tone 3 131.8
Tone 4 136.5
Tone 5 146.2
Tone 6 156.7
Tone 7 167.9
Tone 8 103.5
Tone 9 100.0
Tone 10 107.2
Tone 11 114.8
Tone 12 127.2
Tone 13 141.8
Tone 14 151.4
Tone 15 162.2
Tone 16 192.8
This is the standard in California where the number of wildland fire agencies, the terrain and the heavy wildland fire management workload results in a large number of repeaters per frequency pair. The procedure of California agencies is to use the tone's number instead of the repeaters name. On the Angeles NF, for example, you will hear "Angeles, Engine 27, Tone 13" instead of "Angeles, Engine 27, on Johnstone." This is done for brevity and to eliminate confusion during emergencies when looking up the name of a repeater and choosing a tone number adds an extra step. Standardization is also key for mutual aid. For example when responding to incidents Tone 3 will key up Mt. Hoffman at Yosemite National Park, Glass Mountain on the Inyo NF, Baldy Lookout on the Klamath NF and Mt. Vaca on the Sonoma-Lake-Napa Unit of Cal Fire. When a fire is dispatched the command, tac, and air to ground frequencies are announced, including the tone for the command repeater. All units responding to the fire from outside the area are given these frequencies and tones used. The incoming units don't need to know what repeater they are using, just the tone being used. There are 16 because there are 16 channels per group in a Bendix-King radio and 16 selectable tones per group.
California agencies, with the most notable exception being the Department of Fish and Wildlife,be that the Office of Emergency Services, Cal Fire, State Parks and even Caltrans (DOT) follow this 16 tone standard. In rural areas, such as the one I live in, have followed this plan so that a country sheriff's radio, a city PD radio, a BLM radio and a USFS radio can access the repeaters of all the agencies in the area. Given that most rural counties in the west use VHF, as do the federal and state land management agencies as well, there is true interoperability in place without the complex, trunked radio systems that Motorola, et al, try to sell.
The first 8 are standard nationwide per USFS policy. Unfortunately, the policy does not attach a standard number, or order for the use of these tones. Some Forests have chosen to put them in numerical order by frequency, i.e., Tone 1 is 103.5, Tone 2 is 123.0, etc. In some geographical areas there isn't standardization between units of the same agency. For example Tone 6 might be 156.7 on the Flathead NF and 123.0 on the Gallatin NF. How they program their groups and tone selection must be a bit more complex than it needs to be.
Output tone use varies as well. In California the Angeles, San Bernardino and Cleveland NF's have an output tone of 103.5 for all repeaters. The UHF links and microwave links used to bring that repeaters transmissions to the dispatcher's console allow the system to distinguish the repeater in use. The repeaters are all shown on the dispatcher's console and when a repeater is in use the icon either flashes, displays brighter than the others or changes color.
On other National Forests in California the input tone is also transmitted on the output frequency. This is used to allow the system to identify the repeater in use.
Finally, there are National Forests like the Tonto that transmit a tone different from the input tone on the output frequency of each repeater. The system then distinguishes what repeater is being used. In most cases, this varied output tone is not one of the standard repeater tones, either the nationwide 8 tones or the California 16 tones. When you do a tone search on a federal natural resource agency frequency and see that it is not on the tone list I provided here then you know that this last tone configuration, where the input and output tones are different for each repeater. Mt. Ord has an output tone of 241.8 and an input tone of 123.0. This really doesn't matter for the scanner listener as should you want to program your radio with a channel that is labeled "Tonto NF - Mt. Ord" you would program the channel with 241.8 and don't need to know what the input tone is. However, if you hear radio traffic where the unit says "Phoenix, Engine 62 on Tone 2" you should not program 123.0 in the Mt. Ord Channel of your scanner.
If you have come across a channel plan for the Tonto, it will not show these different output tones for each repeater, just the input. You have to figure out the output tone that is used for a different input tone. Either that, or you rely on someone else to do it and update the RR Wiki showing this.
In the channel plans I've been able to access in the last nearly 30 years, I've noticed a trend for various federal and state natural resource agencies to adopt the tone number of the California plan and even some using tones 9-16 in the same way. They are doing this without national direction requiring them to do so.
I think a national standard directing the 16 tone plan should be policy. As I understand it, one of the issues raised in the Arizona State Division of Forestry investigation of the Yarnell Hill Fire spoke of a disparate tone situation in the radios of the agencies that responded. If one agency was using the nationwide standard tones or the expanded 16 standard tone plan and another was using other tones this would make it difficult for a federal radio to transmit, let's say a tone 88.5 used by a state or local agency because it is not selectable on the federal agency's Bendix Kings. The state or local radio may not be able to receive a frequency unless a tone of 88.5 is transmitted or all the radios of the state or local agencies turn off their tone guard. This may sound like a simple solution, but given the chaos of initial attack or a blowup on an extended attack with new resources arriving on a fire mid shift, without a shift plan in their hands, this little detail might be lost and communications will be compromised. If this is a factor in a single or multiple fatality event then it is time to adopt a nationwide standard.
“We have, I fear, confused power with greatness.” Stewart L. Udall
Last edited by Exsmokey; 08-16-2014 at 8:55 PM..