Homeland Security tries to get local first responders to join the SHARES emergency radio network.[1] This is 5 HF channels at 5 MHz, and some more around 15 MHz. They test on Wednesdays around noon. Transmission is voice or PACTOR. It's ham-type technology for
government emergency response.
Although many local first responders are not on this net, the USCG, military, and Homeland Security monitor it. So it's a way to reach U.S. Government resources in emergencies. This isn't something you access with a handheld, since it requires at least a long-wire antenna. You can get hundreds or thousands of miles of range. The idea is to have something that can get through from a large disaster area.
[1] https://www.cisa.gov/resources-tools/programs/shared-resourc...
[2] https://ema.arrl.org/wp-content/uploads/files/SHARES_Spectru...
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