SC4 Amateur Radio Club

This plan does not imply that frequencies are reserved or only for special use. Quite the contrary; It is a good idea to use these repeaters often and from different locations so you will understand their coverage. The purpose of this plan is to use a common naming convention and group by geography commonly used frequencies that have been suggested in previous plans, making it easier to plan and deploy during events or incidents.

Download this table:  PDF format for reference or CSV format for programming

SC4ARES members may be called to assist during events or incidents. An event is a planned or scheduled activity like an exercise or race. An incident is an unplanned occurrence that threatens life or property, like a storm or an earthquake. An event will typically have a communications plan set up beforehand. During the early stages of an incident you may have to establish your own plan. Your plan should be flexible so that it can change as the incident evolves and expand or contract to meet requirements.

Our communications fall into three broad categories; Control, command and tactical. Control is our communication to The County seat, OES, or Red Cross. The Command Net is the frequency which command, logistics and administrative traffic takes place. Since SC4ARES primary served agency is the fire brigade, we mostly operate at the command and tactical levels, although we may be called to communicate with the Coastside Emergency Operations Center which operates on the control net.

Once units are on scene of an incident, they may switch to a tactical channel for their on-scene communications. The tactical traffic is simplex (radio to radio, no repeater.) As an incident gets larger, more tactical frequencies may be assigned to it. Sometimes on small incidents the command net is also used as the tactical net: If the incident grows, we then move to a separate tactical frequency to relieve the amount of traffic on the command net frequency.

In San Mateo county, OES has divided the Coastside into 3 Branches: Branch 1 from the southern border of Pacifica to Frenchman’s Creek. Branch 2 covers Half Moon Bay from Frenchman’s Creek to Tunitas Creek Rd. Branch 3 covers La Honda, Pescadero and South Skyline from Tunitas Creek Rd. south to the county line (see map.) Each of these branches may then be further divided geographically into divisions if required (eg; Portola Heights, Middleton, Butano.)

To make it easier to choose the appropriate frequency, we have labeled them by category (control, command, tactical) and then in groups with 11-19 being used in Branch 1, 21-29 in Branch 2 and 31-39 in Branch 3. Groups 91-99 are county wide assignments, and 71-79 are used for function specific nets not tied to any branch. Unless you are a participant in eg; Bay Area Hospital Net you can safely ignore the group 71-79 (or 7x) frequencies. Finally we have indicated the tactical frequencies allocated by band (low VHF, VHF and UHF) as the different bands have different characteristics. Low VHF is generally used between vehicles or base stations as the antennas tend to be large, but the signal does carry well among the hills. UHF antennas on handy talkies can be quite efficient for their size and the signal can bounce around in a built up area, but is attenuated by trees and terrain. Familiarize yourself with the options that are available to you and under what circumstances you will us them. You should program the 1x, 2x, 3x and 9x frequencies into your radio for the bands you can operate.

On the command and control frequencies, which generally operate through repeaters, we have included simplex frequencies programmed to match the output of the repeater. Use these in the event of a repeater failure or if you are on the fringes of the repeater’s coverage but within simplex range of the party you wish to reach. These simplex frequencies are indicated by ending with the modifier “D” for Direct. While these frequencies do not use a repeater, it is a good idea to program your radio to transmit the repeater output CTCSS as we’ve indicated in case the other stations you are trying to reach have their tone squelch enabled.