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CDM1250 Alerting Question

Posted: Mon Sep 05, 2011 8:04 pm
by jchabalie
I recently programmed 2 CDM1250's to alert on the designated dispatch channel. When the radio is scanning however, and the tones are activated, the radio does not alert. The scan list is programmed for the selected channel to be the "priority" and the radio is always left on the dispatch channel. Is it possible for the radio to alert while scanning, and if so, am I forgetting to do something?

Re: CDM1250 Alerting Question

Posted: Tue Sep 06, 2011 10:17 am
by speedbird727
There have been a lot of people trying to do exactly what you're talking about. My understanding, however, is that you cannot both scan and have pager functionality set up with any degree of reliability. Perhaps someone else will chime in with better info, but I'm pretty sure best practice is to disable scanning while on your "pager channel".

Re: CDM1250 Alerting Question

Posted: Mon Sep 26, 2011 12:24 pm
by thebigphish
[ redacted ]

thanks, Todd. I missed that post. :x

Re: CDM1250 Alerting Question

Posted: Tue Sep 27, 2011 2:51 am
by wavetar
See my post in this thread:

http://batboard.batlabs.com/viewtopic.php?f=1&t=47540

It details the settings I used in the 'signalling hold time' to get near 100% reliability for QCII alerting while scanning with the CP200, but the same applies for the Professional series. The radio doesn't need to have it's hold time set for the entire QCII length...it just needs to decide of it's a valid set of tones...2 seconds gives it enough time to see the entire first tone, and enough of the second tone to determine it's valid. Same for a long tone...2 seconds of the same tone is enough to determine it should remain on the channel & validate a long tone.

There will always be a small percentage of time where the scan landing is timed so that it happens to miss most or perhaps all of the first tone, in which case the radio won't alert. As was said, if it's a public safety application, you don't want to do this, but for non-critical operations, 98% works fine for most.