Emergency Communication
Fundamentals- Lessons Learned
10 fundamentals needed for serious relief communications are the abilities for the following:
1)sustain a significant emergency power source (not hampered by only low power capability or a hand full of batteries)
2)sustain significant communication distance (HF or high power VHF may be required, good antenna system)
3)sustain personal logistics in your operational area. (must be able to sustain yourself )
4)have good judgement and knowledge of what type of traffic to move ,(identify/ analyze what is significant vs insignificant information , priority/non-priority, best mode if options are available)
5)have prior knowledge/plan on how the local networks are structured (frequencies/identify various net controls anticipated/ primary plan/ alternate plan)
6)always plan with capability to relocate (never only from a predetermined stationary site)
7)have access to gear/logistics above (will you be away from station without access to any of the above when disaster happens?)
8)create kits/ bags small scale response ( tailored kit(s) for limited response and be versatile think out of the box)
9)reflect on your objectives (ham radio, FRS radio, satellite phone, cell phone, VOIP Echolink, IRLP etc or any other means of communication should be used in an emergency)
10)most important of all "hope for the best, plan for the worst" , "do as you did, get what you got" Rick Ching KH7O
POKER (Power Outage Kit & Emergency Repeater) very tactical general use kit for traveling)
General Electric MVP UHF Mobile converted to Repeater 20w
Portable
UHF repeater low power 10~20w. Uses NHRC repeater control board made
for
this model radio. HI-Q Front end, good selectivity excellent overall
radio.
Duplexer is a celwave 6 cavity reject model 633-6A. Only UHF
duplexers
with 5 mhz split can be this small,
Plus side:The best for this size
configuration.
Offers a fairly light weight on the fly repeater
Down side:, range is limited only by actual
repeater location. Low power output.
VHF Simplex Repeater using Radio Shack simplex Repeater module
Economy
version portable frequency agile VHF HIGH power 130w simplex repeater
offers
long range in the smallest package. Good for fast response or temporary
use. Built with a Mirage amplifier being driven with a 1.5w ICOM
2AT HT, Samlex 20amp switching power supply, Radio Shack simplex
repeater
module compatible with (ICOM 2AT, Radio Shack ) type portables or with
similar mic/ptt configurations.
Plus side long Range, Excellent audio on repeat. Quick and cheap solution. Use it with and old Mobile or HT, can use either AC or Car Battery power . Frequency agile, no duplexer needed just dial it up. Use equipment in the shack until needed for deployment. Light weight portable, great for traveling. Equipment can be used in original configuration until needed.
Downside is: you will hear everything you say repeated causing a conversation to take twice as long. Radio Shack repeater module no longer manufactured , typically get it from ebay. Receivers not repeater grade, you may get intermod or deaf receiver if placed in high RF areas.
VHF/UHF Base Station and Cross Band Repeater
Kenwood
TM733A, VHF/UHF base station and cross band repeater. Operate from your
HT to a repeater at a distant location not in HT range, other
applications
such as using it to extend the range from
within
a building or
shelter enabling HT access. Use in short duration activity such as
parades
for extended range from one end to another where there are no repeaters
available. This can be packaged and transported usually fitting
inside
of an old Ammo can or Pelican case for a more modern look. Radio can
double
as a base, or mobile, or even a mobile or fixed cross band repeater,
used
by a few when going into shopping malls to gain repeater access.
Keep in mind in the examples below these are just examples of what can
be done on the fly to McGuiver a communication system immediately.
Plus side: frequency agile, can be used
as
either base/mobile or crossband repeater. light weight. You may have
one
already?
Down side: crossband repeat only, no inband
repeat, users have to have a cross band capable radio to access, Cannot
handle the continuous duty cycle. Receivers not repeater grade, you may
get intermod or deaf receiver if placed in high RF areas.
Extended Long Range using 2 Cross Band Repeaters
Frequencies used are just as an example. It can
be
configured opposite using VHF for the point to point and UHF for the
portables/mobiles
to access with. With this example using 2 CBRs (Cross band Repeaters)
it
is possible to have an extended
range far more reaching then a conventional repeater.The range
limitation
on range is the RF range between the 2 CBR sites therefore by locating
each on a mountain top or elevated location
it
is possible to go inter-island without much effort. In this example the
HT users at each only have to be in range of their respective CBR to
communicate
to the HT at the distant end. The frequencies can be reversed so
that the point to point is on VHF and the HT users are on UHF,
configure
it to what ever meets your needs. In emergency communication operation,
end users usually are using the main communications channels to pass
vital
traffic to a command post and not chatter between individuals therefore
this is perfect for the application. Should the individual users want
to
hear both sides of the conversation they can punch up the VHF and UHF
of
the local CBR.
Plus side: frequency agile,light weight, chances are 2 hams with this type of radio similar to the Kenwood TM733A are already in your area , just needs to be packaged.
Down side: Transmissions are not repeated locally inband therefore although you can be heard by everyone at the distant end, you will not be heard beyond the perimeter of the RF range of your HT or mobile unless users are monitoring both the VHF and UHF frequency which is not a real problem in the late model dual band HTs. Consideration should be given to the technical capabilities of the users or participants in equipment and knowledge on using their equipment in this fashion.Receivers not repeater grade, you may get intermod or deaf receiver if placed in high RF areas.
Using 2 CBRs to make a Conventional Repeater
In this example, a convention repeater is created
by using 2 CBRs in the general area of each other but out of desense
range,
there is no set distance as each manufacturer of transceivers
have
different selectivity specifications for each radio as well as the
power
output and antenna gain/pattern will play a role. Typically a
commercial
radio costing thousands of dollars will have a much superior front end
allowing closer proximity of the transmitting antenna then you would be
able to get away with using ham radio gear. However, by
locating
2 CBRs in the general area but out of desense range of each other, it
is
possible to set one CBR to cross band repeat in only one direction such
as 146.22 Receive and 446.5 transmit and the second CBR to Receive
446.5
and transmit on 146.82. This configuration would operate as any 2 meter
repeater on the air. Frequencies are just examples.
Plus side: frequency agile,light weight,
cheap.,
no duplexer needed
Down side: requires split locations, 2
crossband
mobiles, 2 antenna setups, not continuous duty. Receivers not repeater
grade, you may get intermod or deaf receiver if placed in high RF areas.
HT Tips for extended
operation
Ham Simulated Emergency tests are
done in a fraction of a day and usually with a lot of advanced notice
enough
for everyone to prepare by charging up batteries on HTs or fueling
generators
and being in the right place at the right time scheduling time off of
work
to participate or working around similar obstacles. In the real world
none
of the above will apply. Think of it this way, other then a weather
emergency
which you will typically get some sort of advance warning, all other
emergencies
/ disasters occur on the fly without the courteous notification
process,
therefore you must be prepared with a response plan should it be under
those conditions. You may not be able to go home or to a location to
get
the equipment and supplies etc. Most hams only have one spare battery
pack
for their HT at best and call it quits after that as they cant charge
there
batteries efficiently without commercial AC power. Generally, wall wart
chargers are usually overnight slow chargers except for the yaesu VX5
or
similar with a rapid wall wart. If you already have a fast charger that
can handle 12v then you are set, if you don't, consider getting a rapid
charge desk charger if you dont already have one and use it with
a 12DC to 120AC inverter similar to the one being sold at COSTCO for
approximately
$30. You will then be able to charge the batteries fast
from
any vehicle if the need arises. Zip Loc bag or plastic radio bag as
sold
by West Marine locally is very useful if you intend to operate in
rainy or adverse conditions.