So, a few things to remember about various RF broadcast transmissions...
Lower frequencies have better propagation beyond line of sight. Some of them have over the horizon and even global capability, particularly those in
the lower end of the Amateur band. These require expensive and big equipment to operate, but they are very difficult to 'triangulate' locations
Higher frequencies such as those in the UHF (some of the higher HAM bands) and 800MHz band (typically the ones used for Public Safety) all require
repeaters for anything much beyond line of sight. Virtually everything in the 800MHz band are also strictly licensed, so operator locations are well
known even before they even start transmitting (so no triangulation required).
Anything above this area of the spectrum is strictly line of sight.
Personal radios and walkie talkies have very limited range, usually not more than a few hundred feet. They also have very limited ERP (power).
Cell phones all require repeater towers (it's the very essence of 'cellular'). From a regulatory perspective these are easy to shut down.
Can the US (deep state, or whomever) actually "block" RF? Yes, the military does it all the time, it's called 'jamming' or electronic
countermeasures. Russia has been doing it for decades as have other nations. Can they block it "all"? Theoretically, yes, but it would would be
extremely difficult and require tremendous resources and is therefore unlikely. Plus, electronic jamming is directed at the receiver more so than the
broadcaster, and all the same propagation rules above apply to jamming just like broadcasting because it's just another form of broadcasting.
So in summary, I think the OP's question really breaks down into two different categories fundamentally...
1. Preventing people from talking to one another, and ...
2. Preventing various sources of media from distributing any messages other than those strictly approved for distribution by a government
I think in a true national emergency situation #1 above will really be a non-issue, at least by the hand of the government. There will already be
significant RF communications degradation as a result of the disaster itself, so not much government action is required. The larger issue (in my mind
anyway) is #2 the controlling of media and the narrative. While there are "some" credible reasons to do this, they are few, and it's a very slippery
slope! This type of control can quickly fall into the realm of propaganda and control (i.e. a bad thing).
The other thing you have to consider is where (in the RF spectrum) 90% of the world communicates. With very few exceptions this is line of sight or
very short range (in the case of WiFi). Most of the longer range mediums have fallen from favor due to their low data transmission rates /
capabilities. (People just can't survive without their Fail-Book and texting).
Just thought I'd share.
edit on 6/10/2018 by Flyingclaydisk because: (no reason given)