Cuban Govt Blocks Internet — Jams Ham Radio Freqs

by John Jacob Schmidt

Cuban Anti-Communist Unrest Results in Government Interdiction of (most) All Social Media

Facing some of the worst economic conditions in recent history, Cuban citizens have taken to the streets since this past weekend, protesting the communist regime’s policies and demanding economic relief, their freedom, and an end to communist rule.

In response, the Cuban government began implementing strict internet controls on Sunday, with special emphasis on social media platforms.  According a Yahoo News Article, the government specifically targeted Facebook, WhatsApp, Instagram, and Telegram.  This, according to Alp Toker, director of Netblocks, a London-based internet monitoring firm.

One very interesting detail to note was the following sentence:  ‘Twitter did not appear to be blocked, though Toker noted Cuba could cut it off if it wants to.’

This is most likely strategically intentional.  In the SIGINT (Signals Intelligence) world, this is referred to as ‘Comms Herding’ — the deliberate funneling of an adversary’s communications into a manageable, easy to monitor and analyze environment.  Open Source (OSINT) resources are available which allow for the application of ‘analytic tools’ on social media platforms, especially Twitter, which aid in the analysis of trends, texts, videos, chats, etc.  This is invaluable information to determine (in real time) actions, movements, and the actors involved, and to include predictive capabilities.

Hopefully the activists in Cuba will take note of this and adjust how they communicate and what they’re saying openly.  The WW2 OPSEC and COMSEC posters are a timeless reminder — ‘Remember:  The Enemy Is Listening’.

Ham Operators Take to the Air:

Since the weekend, Amateur Radio operators in Cuba began reaching out to fellow hams in the United States.  One American, of Cuban descent, has been taking the lead on the effort to keep us all informed of the latest developments in Cuba.  On his Youtube channel, W7HU Alex, he posted the following narrative along with his video describing the situation on the ground, based on reports he has received from Cuban citizens:

The Cuban Government has shut down all lines of communication to the island including internet access and right now the people are in the middle of a Humanitarian Crisis. As soon as we started to pass information back and forth on 7/11 the Cuban totalitarian regime started to cause malicious interference on the SSB portion 40 Meter US Band from 7.125-7.125 making the section unusable. If you are a ham anywhere in the world and can hear this please report the jamming on this QRZ forum link below:…
(Alex begins describing the situation at about 9 minutes, 15 seconds into the video, so I started it there)


Cuban Government Begins Jamming portions of the 40m Amateur Radio Bands (and the area of jamming has increased since):


Radio Direction Finding Narrows Source of Jamming to Cuba:

This excellent video by Ham Radio Crash Course demonstrates Radio Direction Finding (RDF) using web-based SDR (Software Defined Radio) receivers,
which confirms that the signals are emanating from on or near the island of Cuba.



As AmRRON Corps operators have been tracking these recent developments, we also had the opportunity to conduct real-world
testing in an intentional jamming environment by a malicious communist government actor.

  1.  The jamming (reportedly using 5000 watts of transmitting power), primarily affected voice communications, making it extremely difficult for stations using voice to copy each other.
  2. As the affected ham operators moved up and down the band, they were often followed, indicating ‘frequency agility’.  This means they are actively following ham operators and moving to jam their signals after moving away from the portion of the band being jammed.
  3. AmRRON operators on the east coast and southeast portions of the US were able to successfully exchange text messages and files using digital modes inside the affected portions of the band being jammed.  The jamming did not prevent digital mode communications, which is another testament to digital modes.
  4. This also prompted a discussion of exploring alternative frequencies within each of the bands we operate in for AmRRON operations.  We could easily coordinate this among ourselves using internet-based texting and chatting apps.  But if the internet was blocked, operators would need to know where to move to by either coordinating over the air, or by taking the initiative when we’re not able to coordinate at all.

So far, we’re not aware of any declarations or laws being passed banning the use of Amateur Radio in Cuba.  Although, that is something that might be expected.  At this time, we’re not aware of any repercussions against licensed ham operators, including warnings or visits by authorities, or any directives being issued related to ham radio.  It only appears that the Cuban regime is conducting ‘harassment’ measures against ham radio operations.


More updates as they become available.