[EAS] Attention signal on an RMT

[Sean Donelan]

On Thu, 30 Mar 2017, Randall Miller wrote:
> How many EAS decoders out there USE the attention signal to know when to start recording the audio content?
> I'll bet most if not all.

As far as I can tell, its the opposite.

EAS decoders immediately start "recording" after the EAS header data burs

When they detect several seconds of an Attention Signal or Weather Radio 
Tone, they "rewind" the recording until the tone stops.  Its all digital, 
so they likely just change a pointer in the audio buffer - no actual 
rewinding of recordings.

That's why you sometimes end up with double or triple attention signals. 
If the tone is garbled or out-of-spec, the original tone is not removed 
and a additional Attention Signal is added during the relay process.