Radio spectrum is licensed, and licenses are very expensive.

There are several bands for Amateur radio in US/EU/AU, but it is explicitly forbidden to use any kind of encryption on them. So no one can sell devices that use encryption on those bands.

And I doubt Iran was friendly to amateur radio in the first place. E.g. in USSR it was crazy to think of any non-approved radio.

I mean who can stop you from transmitting anything you want at any frequency? Licenses etc only matter when the rule of law is a thing.

It's trivially easy to watch the entire radio frequency range at once and triangulate the location of any transmission. If someone more powerful than you wants to stop you, they can.

Just curious what if the transmitter hops freq around? What is the tech to track these?

It's (scarily) available in the commercial sector[1][2] from space if you have the need to purchase their services.

Suffice to say, military and intelligence agencies are probably a few generations ahead of this and you won't find them commenting on strategic capabilities on HN.

1. https://www.he360.com/ 2. https://spire.com/space-reconnaissance

Thanks! Technically, what do you think is the biggest obstacle to achieve military grade hopping? Is it just cost, or something you simply cannot buy from open market AND cannot make one if you have the knowledge?

Military frequency hopping / spread spectrum isn’t really about preventing being noticed, it’s more about making it harder to jam. If you don’t have physical safety from the people “more powerful” than you who want to stop you, then they will still locate you easily and stop you using physical force.

Parent was asking about jamming protection (frequency-hopping, encryption) devices.

Once you transmitted, you’re exposed so the authority can find you sooner or later

Well yes but you could of course choose not to stay at the location you transmit from.