Monday, July 16, 2007

Log Extract: Long EAMs Are Not Remarkable

As I suspected, previous reports published in our Utility Logs column have indeed shown Emergency Action Messages (EAMs) that were as long as, or longer than, the 174-character one of June 26 that has aroused attention. Recall from my previous blog entry that this EAM has been cited by unknown Internet sources as the longest since the first Persian Gulf War.

It isn't.

This would tend to reinforce the argument made by a writer to Bill Gertz's column, who was quoted in the same post, that long EAMs generated by periodic exercises "should not be considered unusual."


Long EAM Examples:

Jeff Haverlah, a long-time Utility Logs contributor and generally Mr. EAM in this hobby, reported the following on February 17, 2007:

1729z 17 Feb 07

11175.0 was active at 1431z with OFFUTT bcsting a 248-character
EAM (TOXRB7) containing common, repetitive, distinctive formatting,
including the 14-character ending block common to these strings.

11175.0 was active at 1717z with OFFUTT bcsting a 163-character
EAM
(TO57UN) containing distinctive (but not apparently repeating)
formatting including the 14-character ending block common to these
strings.


(Emphasis mine, for readability.)

Also from Jeff, this report of March 10:

0039z 11 Mar 07

11175.0 was active at 101722z+/- with OFFUTT (weak with deep
fading) bcsting a 201-character EAM (TOCDIJ) containing distinctive formatting and ending in a common 14-character ending block.


And, on 26 May, again from Jeff:

1555z 26 May 07

11175.0 was active at 1447z with ANDREWS (good levels here)
bcsting a 202-character EAM (IV3PR6) containing distinctive repetitive formatting (but did not end in the 14-character ending block common to these strings.) Activity common to utc Saturday's (1447z 28 Apr 07 245-character IVLZ7S) for example.) All Andrews xmsns are keying off with a soft pop/thump.


And, on June 23 near the beginning of the June 25 period in question, from Jeff:

1434z 23 Jun 07

8992.0 was active at 1418z with ANDREWS (good/fair levels here)
bcsting a 121-character EAM (IVSAD2) containing distinctive, repetitive formatting.


Conclusion:

It seems significant that all of these long messages appeared at roughly one-month intervals, and on UTC Saturdays. There is a suggestion here of a monthly activity (likely a communications exercise) that generates long EAMs. We can therefore conclude that, while the June 25 activity was noteworthy for call signs, traffic volume, and a special test string, it was very much not noteworthy for EAM length. The writer to the Inside the Ring column appears correct.