[sbe-eas] EAN test

[Fawcett, William - fawcetwd]

I'll be yanking my max-headroom Burk endec today and will try to recreate the situation with a high quality recording; so it should not be any big deal to forward the audio past the first set of breeps and decode the second. 

My guess is that FEMA did not read  Sage service bulletin SB 001 and received bleedthru from an input monitored on the endec.

-Bill Fawcett



William D. Fawcett
Shenandoah Valley Emergency Alert System
983 Reservoir Street
Harrisonburg, VA 22801
(540) 568-3809   fawcetwd at jmu.edu



-----Original Message-----
From: sbe-eas-bounces at sbe.org [mailto:sbe-eas-bounces at sbe.org] On Behalf Of David Brant
Sent: Thursday, November 10, 2011 10:40 AM
To: SBE EAS Exchange - a mail list for discussion about the EmergencyAlert System and other emergency communication issues.
Subject: Re: [sbe-eas] EAN test

Has anyone had any luck decoding the data from the extra headers that occurred about 5 seconds into the test?  That could shed some light on where they came from.  My old TFT-911 box (out to pasture) won't decode them, but I'm still trying. 


David P. Brant
Chief Engineer
Fox Television Stations, Inc.
WHBQ-TV
485 S. Highland St.
Memphis, TN  38111
(901) 320-1206

-----Original Message-----
From: sbe-eas-bounces at sbe.org [mailto:sbe-eas-bounces at sbe.org] On Behalf Of Harold Price
Sent: Thursday, November 10, 2011 2:53 AM
To: sbe-eas at sbe.org
Subject: [sbe-eas] EAN test

Getting the 2nd set of headers send from high up the chain was unexpected, however.

If the ENDEC receives a 2nd set of headers on a monitor input that is currently in an alert, it assumes that it missed the EOM from a previous alert (see #2 above), and starts the process of ending that previous alert.

That 2nd set of headers, if it was decodable by the receiving station, terminates the audio "early"; the recorder is restarted, causing the output to mute.  It only takes one properly formatted header to do this.
If you decoded one of the 2nd group of headers, your audio appeared to mute for several seconds.

Only one header is sufficient to cause the input audio to mute, but not sufficient to detect a valid new alert.  If you decoded only one of the 2nd set of headers, you did not get a log of that alert - because it takes two headers to be a valid alert.  If you decoded two, the alert was logged.

Regards,
Harold



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