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Advice on building a setup

Michael Lampen

New Member
Mar 29, 2019
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Hi all,

You all have a very complex hobby here which I admire. Thank you for taking the time to read my post. I'm hoping some of you would be willing to share your years of accumulated knowledge and experience to steer me in the right direction. Although, I have plenty of hobbies myself sailing, hunting, fishing and of course my involuntary and most demanding hobby which is unfortunately my job. I have to admit that I've only put in a fraction of the endless hours required to attain the knowledge necessary to answer my basic questions. So thank you in advance.

I'm looking for a disaster communication system for immediate family members. 3 couples making 6 people total. The requirement is for us to be able to communicate assuming no power, no cell access, no internet access. I included a map with our approximate locations and distances below. There is a key on the map as well. The lowest mark for the 3rd home is much farther south than what is show on the map. Figure 15 miles further south over kind of a mountainous terrain.

As you may already know, San Francisco is a mountainous and urban environment. What would be a good set up to ensure we can all communicate should the megaquake strike or other disaster scenario? Keep in mind, we'd want to be able to communicate as soon as possible without getting put in to a queue and waiting hours or days for our few minutes of air time. I'd like immediate capabilities to communicate over a mostly clear channel.

So far, I've learned relying on repeaters is not a sure bet considering they'd be overwhelmed if they're even operational. Best bet is to have base stations at each home with 80+ watt setups (with back up power) that would communicate directly with each other. Then each person would have a handheld which can communicate with whatever base station they're in closest proximity to. Base stations could then communicate with the other base stations tying everyone together.

Communication is the number one priority for us so we can determine best course of action depending on the endless possible disaster scenarios for Bay area.

Once I can figure out best set up for our situation, then I'll need to choose the gear itself.

Work Home Comms Layout Illustration.png


Any thoughts and advice is greatly appreciated!! Thank you.
 

That's a pretty RF-intensive part of the world. Just packed with transmitters of all frequencies and uses. If you're looking to have an independent network to communicate those paths totally off-grid, you'll probably need to elevate the antenna above ground level at more than one of the locations shown.

A ham license for every participant would open up a lot of possible solutions. License-free options will be more limited.

The lumpiness of the terrain is an issue. If one of your locations is "hiding" behind a hillside from one or more of the other locations, that becomes a problem. The magazine QEX had an article recently about using the KML language to display elevation plots between two map points. Gotta figure that info can be found elsewhere, as well. I would start with discovering how deep a shadow the terrain will cast in each of the paths you want to cover. That will suggest what radio frequencies may be viable and which ones won't without a tower or tall building to support an antenna.

Then again, the seismic rating of an antenna support might be the real factor determining whether or not your network can communicate when you need it.

73
 
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Thanks Nomad.

Both locations can have elevated antennas. Brothers place in the city is on the 4th floor and could set up an antenna in the corner windows or possibly on the roof of the building. My place to the north is elevated and could possibly setup an antenna off the roof as well.

Hills definitely are an issue. My place does not have direct line of site to my brothers and there are a lot of hills and obstruction in between. Then, there are hills and buildings between our work and my brothers place. So that's a challenge as well. I looked at your suggestion for mapping with KML. It seems a little dense and I don't have any experience with something like that. I'm not sure I'd have much success with that approach. Is it possible to come up with a recommendation without getting to that level of detail?

Also, we're all open to getting licenses, that will not be an issue.

I also forgot to consider, I do have a sailboat on the water front that I could hook up to dock electricity. I'm planning to run a new antenna up the mast this spring anyway. I'm not sure how to leverage the boat but it has a much clearer line of sight to my brothers place in the city. Not sure if that would solve any issues or complicate the hell out of this.

Work Home Comms Layout Illustration.png
 

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