Disaster
Radio
Using Amateur Radio during Disasters and Emergencies
in Hawaii
Last update
Choosing
a radio
for emergency communications
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?
a radio
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
an antenna
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
Miscellaneous
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 either Molex or
Anderson Powerpoles ( links in Disaster
Radio site)
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.
Contact us
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