Emergency Comms with NVIS
In a worst case scenario, where the power is out along with the phone (including cell towers) and internet, there will be a real need for some type of ability to communicate locally (greater than 25 miles away) as well as nationally. The only option for near (State wide) communications is to use a mode called Near Vertical Incident Skywave (NVIS). This us where you intentionally transmit your signal in a mostly vertical direction and bounce the signal off of the "F" layer of the ionosphere to cover a 300 mile or so radius. Unfortunately, not all frequencies will effectively utilize this method and you are limited to frequencies of 10 MHz and lower. The best bands during the day are usually the 40 meter (7.000 to 7.300 MHZ) and the 80 meter (3.500 to 4.000 MHz). At night, you can use the 80 meter and the 160 meter (1.800 to 2.000 MHZ) for best results. With no power, using a larger and more powerful ham radio sets for Single Side Band (SSB) voice will be difficult unless you have already set up for that possibility so you may have to use a small, battery operated transceiver using Morse code (CW) (SSB requires more transmitting power than CW). The upside of using CW is that you can usually cut through background noise using only a watt of power or less where SSB will not. In addition, CW takes up less of the band thereby allowing more operators to get on the air to send radio messages.
COMING SOON - you will find some pictures and diagrams of how to set up and be prepared for emergencies by using a low power (QRP) radio with an NVIS antenna)
First, a primer on propagation theory:
COMING SOON - you will find some pictures and diagrams of how to set up and be prepared for emergencies by using a low power (QRP) radio with an NVIS antenna)
First, a primer on propagation theory:
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