In case phones are down and stuff during a disaster, what would be the best way to communicate? Ham radio? Satellite phone? I need options guys.

  • BearOfaTime@lemm.ee
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    2 months ago

    For 50 miles you’re going to either need HAM or a repeater on anything else.

    Even then, geography will be a huge determinant. Radio is generally line-of-sight, which is why things like GMRS/FRS and CB are limited to 5 miles - the general distance to the horizon.

    I don’t remember the math for antenna elevation and line-of-sight, but for some reason I have 30ft in my head for 10 miles, given flat country (no hills in the way). Don’t quote me on that, but it’s an example of how elevation affects range.

    Fifty miles is a challenge, unless you can get an antenna really high, or are able to setup a chain of repeaters (I’m not sure how legal this is, GMRS regs are pretty open).

    HAM isn’t limited by line-of-sight because it can reflect off the atmosphere, but it takes skill at both ends to know how to manage this. Think of HAM as using the atmosphere as a repeater, but one that’s constantly changing frequencies, and you have to figure that out at any given time based on conditions (and it’s not always available between 2 locations because of those same varying conditions).

    I think your best approach for now is to start with GMRS - it’s an inexpensive start, and you’ll learn this stuff with hands-on. Setting up your own GMRS repeater is pretty easy (once you have a little knowledge), has minimal regulation, and you can get several miles pretty quickly. There’s a repeater about 4 or 5 miles from me (on a tower) that provides a connection to vehicles on the interstate more than 10 miles away. Being elevated means the repeater can “see” a lot farther.

    Here’s a good place to start.