non-cellphone emergency communications

Non-Cellphone Emergency Communications

OrHow I stopped worrying and learned

to love smoke signals

By Tim Weaver

The Situation

• The Government in Exile of Mali (fka Upper Volta) has learned the secret of destabilizing Western society

• The economy of the United States as collapsed

• Normal infrastructure has ceased working, making normal communications by cell phone or landline impossible or impractical

Task

• How to communicate with others– In person

• Obvious issues regarding geographical limitations

– Couriers• Trust, geography

– Semaphore• Really?

– Radio

Action

• With whom are you planning to communicate?

• What distance do you need to communicate?• Scheduling?• Method?

Action

• What distance do you plan to communicate?– Local (0-35 miles)– Mid (35-800 miles)– Long (800+ miles)

• Scheduling– You can’t just call them any time like you can with

a phone– Certain times of day may be better than others

Action – Short Distance

• 0-35 miles• Primarily FM mode• Line of Sight• Mobile (vehicle) are more powerful• Handy Talkies (HT) are convenient

– FRS / GMRS Radios• Don’t believe all the marketing• GMRS technically requires licensing, but fast becoming

new CB radio

Action – Short Distance (cont’d)

• FRS / GMRS– Fixed “channels”– Not secure– GMRS requires license; FRS free– Low power (0.5-2 watts)– Only GMRS radios can be altered– Realistic Distance

• FRS – Zero to two miles• GMRS – Zero to five miles

Action – Short Distance (cont’d)

• Ham Radio– Frequency range versus ‘channels’– More robust equipment– Much more configurable– Higher legal power output – 5 to 50 watts common

(HT or mobile, respectively)– License required AND enforced– Repeaters can extend range significantly– Directional antennas can extend range significantly

Action – Short Distance (cont’d)

• Other– “Land Mobile” – such as used by taxi services,

construction companies. Can be very robust radios. Programmed channels only.

– Marine Radios – supposedly legal in areas beyond a certain distance from ‘navigable waters’. Otherwise limited to lakes, rivers, oceans, etc.

– Both are very enforced by the FCC

Brands

• FRS/GMRS – Motorola, Kenwood, Maxon• Ham – Yaesu/Vertex, Icom, Kenwood, Alinco• Land Mobile – Vertex, Icom

Action – Long Distance

• Remember CB Radio?– “Skip”– 27mhz / 11 meter– Power output

• 4 watts for “normal• 12 watts for Single-Sideband (SSB)

– Bandwidth• AM vs SSB

Action – Long Distance (cont’d)

• Welcome to High Frequency Communications – HF relies on bouncing the signal off the

ionosphere– Some frequencies will never bounce; others will

rarely bounce– Maximum Usable Frequency (MUF) will vary from

time of day, every day. Usually higher during the day (7mhz range, 40 meter Ham) and lower at night (3mhz range, 80 meter Ham)

Action – Long Distance (cont’d)

Source: MCRP 6-22C, Radio Operator’s Handbook

Action – Long Distance (cont’d)

• HF can be used to communicate across the globe

• Sometimes, farther is easier due to skywave• Extremely modular, with nearly anything

possible if money or imagination + skill isn’t an issue

• Power from 5 watts to 1,500 watts– Some people enjoy the challenge of low power

communications (<20 watts)

Action – Long Distance (cont’d)

• How to get into the “Skip” Zone?• NVIS – Near Vertical Incidence Skywave

– Low antenna “shoots” signal straight up– Comes down like a dome– Distance – 30 to 800 miles– Usable frequencies 2mhz – 15mhz

Action – Long Distance (cont’d)

Action – Long Distance (cont’d)

Action – Long Distance (cont’d)

• HF Communications are generally not plug-and-play

• Very dependant on knowledge, atmospheric conditions, sun spot cycle, antenna and, frankly, luck

Action – Long Distance (cont’d)

• Brands– Icom, Yaesu, Vertex, Kenwood

Action – Long Distance (cont’d)

• What about military “backpack” radios?– Heavy – 15-20 pounds without batteries

– Expensive - $1,000 +

– Hard to repair– Battery availability is a big issue

• Examples– PRC104– PRC2000– PRC515– PRC1099– PRC320