squad1b
Member
do i need both the Alternate and control channels to make a scanner pick up talk groups properly.trying to get MPLS FIRE.
Scott
thanks in advance for your help
Scott
thanks in advance for your help
Last edited:
With a scanner, the only other time you’d truly want all channels of a system (apart from a Harris setup) is for failsoft but I don’t exactly know how a scanner would handle failsoft.
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For scanners, you'd have to have the frequencies programmed as conventional - and then know the site/system failed and manually switch over to that programming on your radio.
It might be a cool feature (!) to allow for a trunk system to be programmed (as an option) such that the scanner automatically started using the trunked system/site frequencies as conventional (and go into some type of visual/audible alarm status) if/when the control channel is lost. Of course, for many scanner users, they'd probably be switching to "pseudo failsoft" alot given that it is a scanner and can't always find the control channel (mobile applications, simulcast problems, etc,). But that's why it should be an "option" for the user (like, for example, whether or not I want to know and hear encrypted talkgroups).
For now - it's "have a scanlist programmed as conventional" and know there is a problem ... which may be really hard to do - I've missed "silence" on really busy systems sometimes because in many cases, it's just another thing I'm hearing -or not- "in the background").
EDIT: not sure about P25 Phase 2 and failsoft - I assume the system reverts to conventional P25 Phase 1(FDMA).. reducing capacity by 50% - and kicking some users off completely (or they become so low on the priority they don't get airtime) due to that reduced capacity. I suspect things like public works might probably get prohibited in failsoft but of course, it all depends on the system.
I know what you mean. When scanning some P25 frequencies in conventional mode, it sometimes seems like there is an open/idle carrier on some frequencies. Radios would have to be smart enough to detect this and ignore it.I see some issues with that as when a site goes into failsoft, all repeaters begin transmitting so the only way to differentiate traffic would be via talkgroup. Not knowing exactly how the scanner scans P25 exactly when in conventional, it may hang up on one of those channels even though no voice traffic is being passed.
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