Sporadic Network

This network consists of a large group of F06, F01, E06, and S06 schedules that transmit only a few times a year, to which at least these belong:

• F06: 30011, 90017, 00030, 40034, 10042, 70082, 30088, 00089
• F01: 0800z, 0915z, 0920z, 0930z, 1100z, 1110z, 1350z, 1410z, 1415z, 1900/2000z, 1945z
• E06: 158, 192, 216, 346, 548, 634, 657, 759, 826
• S06: 387, 409, 583, 726

With few exceptions, most of those schedules transmit twice a year during either the first or the second week of March and September. None of these links ever carry null messages, while some may not broadcast at all during one "season" but return for the next. The F06 and F01 links maintain continuity in the messages' serial numbers between appearances.

Each "season" also sees some activity using backup modes like F06a. Unlike the F06 and F01 links above, which carry standard messages (headers beginning with 11166) and appear regularly over the years, the F06a activity involves drill messages (headers beginning with 11100) and different link IDs every "season."

This network has been active since at least 2012, with a growing number of schedules appearing over the following years.