Cuban Network

This network consists of F01 and F06 transmissions made from Havana, Cuba, including at least the following regular schedules:

• F01 00116
• F01 00117

These schedules consist of two transmissions spaced 10 minutes apart, and then another two an hour later on the same frequencies. Null messages are never sent; instead, a pre-defined stream of digits, shared by all link IDs, is sampled at a random point to create some dummy groups. Serial numbers are reset to 1 at the beginning of each year.

Operations on this network seem to be manual and are sloppier and more prone to errors. Transmissions tend to start early or late, and usually end abruptly after completion. The transmitter's output occasionally features malfunctions, e.g. by beginning or ending the message on the wrong block, or inserting unexpected line feeds at regular intervals.

Other link IDs historically based in Havana include 00119, 00125, 00127, 00128, 00135, 00139, 00148, 00168, and 00224. A few of these (00125, 00127, 00128, 00139, 00224) have also been reported in the 2010s using both F01 and F06, although their activity is irregular and unpredictable.

It appears that there is only one transmitter available at the Cuban facility: on 12 October 2018, one of the four scheduled transmissions on the link 00116 didn't take place, in favor of an unscheduled message on the link 00127 on another frequency.