[EAS] RWT trigger detection

[Mike McCarthy]

The problem is our network content providers use those tones for 
control, but are not filtered. Our closures come from the receiver 
directly.  So they roll right through the system to the processor where 
they're filtered off before going to the TX.  This is quite common 
actually across many networks.  So sub-audible would be a bad choice.

I'm not partial or committed to DTMF. I'm merely using it as an example. 
It is however convenient and already available, simple, reliable, 
flexible, security friendly, widely adopted with a great deal of 
equipment available, can easily handle the task, and is MUCH less costly 
than 25/35 decoders.  I'm open to other suggestions in the same price 
class which might have a bit more security.

I don't disagree with you on the annoyance factor. But this is once or 
twice a week event using a pair of tones.  No different than using DTMF 
as a back-up TX remote control on the STL.

One other lister asked about security.  I advised on a wired circuit 
(T1, program loop, etc.) or digital circuit (AES STL), who can hack it?  
And even if the circuit was hacked, all they'd do is spit out one RWT a 
day before we accessed the machine to disable remote test triggering. I 
could see that possibly being an issue on a single/dual mono analog 950 
system however.

MM

On 7/6/2012 12:56 AM, Alex Hartman wrote:
> Instead of the god awful DTMF tones of yester-millenium, why not use
> 25/35 subaudible tone systems? I'd assume the DTMF would trigger a
> statewide/network-wide RWT/RMT anyways, but does your audience need to
> hear the telephone? Every time i go through Wisconsin, with their
> satellite distribution system, every break i hear DTMF and think to
> myself "what year is it?"...
>
> Just throwing it out there. DTMF is probably just as cheap to do as
> 25/35, i know you can homebrew both.
>
> --
> Alex Hartman