This article offers criteria for reasonable choices for an emergency communications radio.
The most likely scenario for emergency communications is a ham radio operator stationed at a fixed site, such as a supply point or community shelter.
You will be inside a building, possibly surrounded by other buildings, with or without commercial power.
You will be in contact with a net control station, with luck via a repeater, otherwise via simplex.
So, what do you need?
- with a band to match net control; better yet a dual-bander
- enough power to communicate simplex, if need be
- a low power setting to conserve electrical power, such as a battery
- CTCSS capability to match the repeater, if need be
- small enough to be easily transported by hand
- reasonable choice is a dual band mobile 2M / 440 radio
- see below for HT considerations
a power source
if commercial power is available
- an AC power supply
- preferably a switching power supply for light weight
- a 25 or 50 feet extension cord (the outlet is always across the room)
- a power strip (someone will always want the outlet and unplug you)
if no commercial power
- one or more batteries
- gel-cell batteries preferred to prevent spillage
- deep cycle batteries preferred to provide extended power
- enough amp-hour capacity to last several days
a power cord with connector to match the radio
- quarter-wave or larger
- vertical with minimum radials
- a good choice is a 1/2 or 5/8 wave mobile dual band vertical with a UHF connector base
- one or more mounts
- magnetic mount – attach to any steel surface, car, refrigerator top, file cabinet, steel beam, baking pan, etc.
- L-shaped clamp – attach to railing or improvised mast (stick, light pole, etc)
coax – at least 50 feet, 100 feet better, RG8 for low loss, RG8X as best compromise for weight and bulk
- PL259 / SO238 (UHF) connectors on coax
- UHF barrels to interconnect coaxes
- Headphones with full ear muffs – it can get extremely noisy in an operational area.
- Other usual supplies for operations, from your 72-hour kit (you DO have one, don’t you?)
Notes and suggestions:
- Standardize all power connectors on your equipment to Anderson Powerpoles
- Standardize on UHF connections for radio, antennas and antenna mounts
- If you use an NMO mount on your car, get an NMO-UHF adapter so you can replace the car antenna with the one described above.
- Make a 10 feet power cord with a standard power connector on one end and big clips on the other, in case you need to draw power from a “commandeered” car battery.
Notes on HandiTalkies:
- Get an alkaline cell adapter for your HT – and lots of AA cells
- Make / buy a power cord for the HT with a standard power connector at least 6 feet long (12 feet better) for battery use.
- Get an adapter for your HT antenna connection – from BNC or SMA to UHF.
- Get an amplifier (called a “brick”) to boost the 3-5 watts of the HT to 35-50 watts
- Ensure the amplifier has standard power connectors
- Ensure you have a cable to connect the HT to the amplifier
- A dual band amplifier has obvious advantages, but it costs more.
Final comment for mobile radio users
In an emergency, can you detach your mobile radio from your car and move it into a building is a reasonably short time?
- Do you have the appropriate tools in the car to detach the radio?
- Do you have an appropriate power cord to operate from either an AC power supply or 12 VDC battery away from the car?
- Do you have a coax and antenna to operate away from the car?
Do it and time yourself. Especially if you have a remote head mount in the car. Can you re-assemble the radio quickly in the building ready for operation? This is the time to find out, not during the real emergency.
795 total views, 3 views today