Simulcast?

[SKYNET156]

I am wondering if you can program a simulcast frequency into a radio as RX only on a P25 trunking system to hear all voice ops from all talkgroups?

I recently posted this question in the north carolina forum and got no distinct reply,

I know if you program the voice channels of a trunking system as conventional channels, you will be able to hear all the talk groups come across the voice channel, but because the radio is not an affiliate of the trunking system, you can not listen to a specific talk group,

so my question in short form is :

can you program the voice channel to listen to traffic conventionally? and because this is a P25 trunking system, do i have to program the voice channel in P25 Conventional with OPEN NAC?

any advice would help

[rdale]

Not sure what you are asking... Simulcast frequencies work the same as non-simulcast. If you don't put them in trunked mode, you can't follow.

[SKYNET156]

i was able at one time to monitor the FT Lauderdale system years back when it was analog trunked, i did not have a trunking scanner back then, so i entered the frequencies as conventional and i was able to hear voice traffic on the trunking frequencies when i programmed them in conventional mode, i was not able to hear Talkgroup traffic, but it was more like all the talkgroups cycling through the conversations, i dont know how to explain it correctly, so help me out here if anyone knows what i am speaking of,

thanks

[wlmr]

I'd like to Echo what rdale just said and add some.

Short answer - no.

Short explanation -
For your question, doesn't matter if it is Simulcast or a regular trunked system, trunking is what determines the answer.

If you're not talking about a scanner but an actual radio, for trunking systems either you get everything on the voice frequencies but can't follow the talkgroup conversations,

or

You have to program the radio for the system and you're limited to 15 talkgroups because that's all the radio is capable of scanning at any one time.

You'll never be able to listen to ALL the talkgroups with a regular radio like your original post, only 15.

ALSO IF YOU"RE TALKING ABOUT A REGULAR RADIO, (Intentional shouting)
at this point you need to stop asking questions and use the search at the top of page to find references to programming radios on a trunked system, system keys, radio affiliation, receive-only radios, bricked radios, and other warnings about why this is a hot-button topic.

If you have a scanner, things are immensely easier.

[wlmr]

Originally Posted by SKYNET156

i was able at one time to monitor the FT Lauderdale system years back when it was analog trunked, i did not have a trunking scanner back then, so i entered the frequencies as conventional and i was able to hear voice traffic on the trunking frequencies when i programmed them in conventional mode, i was not able to hear Talkgroup traffic, but it was more like all the talkgroups cycling through the conversations, i dont know how to explain it correctly, so help me out here if anyone knows what i am speaking of,

thanks

An example would be walking from room to room during a party listening to conversations from others who are also moving room to room in their own patterns. You get bits of each conversation but if it lasts any length of time at all you're now listening to another conversation. You may get to hear more of an earlier conversation later on when they and you pass near again but you may never make any sense of any of it.

[SKYNET156]

Thanks for all the info,

i am fully aware of the legality and equipment that is needed to program a system key for a trunked system, but that is not my intention at all.
i would not want to make my XTS into a brick and then tell the state of north carolina that i tried to acsess their VIPER system illegally, lol...that would be alot of explaining to do...

i am not sure how to explain my question, all i know is that you can program the frequencies in conventional mode to listen to the system as non trunked, i know it works with multinet systems to monitor them, i am just not sure that it works with P25 Smartzone systems?

[wlmr]

For conventional receive-only monitoring it would sorta would work the same for P25 as it would work for an analog trunking system, you would get exactly what I tried to describe in the message just above your reply. Depending on how active the system is, running screaming into the night is a possibility after any length of time trying to follow conversations. If you catch yourself singing "They're coming to take me away ha ha, they're coming to take me away he he - ", it's way past time to get a scanner.

[SKYNET156]

lol...I kinda figured that, i am just doing this as a project, i have a 396T and 996T that i use for the VIPER System, and even then i use my computer to monitor it with the software...i am just wondering if this works as i explained it,

now, my next question is,

What are the voice channels that i want to use, i dont think it works with the control channels because of the constant flow of data, all you hear is that data sound with the control channel, so what do i want to use? the alternate channels?

[wlmr]

Voice conversations can go to every frequency at a site that's not the current control channel. And even then you'd need to keep the current control channel available for if/when the system switches to an alternate.

You're almost ready for the second verse of that song, I can hear the pitch of the song getting higher & higher!

[SKYNET156]

im way past the second verse, ive been sitting here programming the XTS5000 and it wont let me write the code plug because it's saying i need to revert in modat, IM NOT EVEN USING MODAT!! :dead: xx(

so i am going to try it and just see what goes on, wish me luck...lol

[tunnelmot]

I currently use an XTS to conventionaly scan a 9600 P25 simulcast system. You loose the ability to park on a single TG, but that was my ONLY option since the simulcast can't be handled properly by the newest generation of scanners.

There are ways to give you some selectivity in TG selection on Astro TGs.

Depending on your nearest site, what TGs youre interested in, how busy the site/system is, etc, you can be quite surprised at what you can achieve by never pulling up the trunking menu.(ie: no legalilites)

No sys keys, no hacking, no legal issues whatsoever...and it works fairly well. 100% conventional.

PM me if you like.

[wayne_h]

I recall reading a thread on Batlabs that described how to monitor specific talkgroups that used P25 voice (so either 3600 or 9600 trunking) in conventional mode. Since the P25 stream always contains a TG (like a NAC) you can exploit that feature. To follow a TG you have to scan all channels so you're limited to 16 channels and the possibility of missing a conversation since the scanning slows on busy channels. You also have to set the NAC. Enable TGs and make sure the TG matches what the CC sends. That's all I remember. Head over to Batlabs and search for it, otherwise stick to a scanner.

[immelmen]

I would add you may need the correct NAC, in addition to Talkgroup info, for the tower your scanning rather then the magic F7E "open NAC" as this blocks all selectivity out of the data stream of the transmission(Radio ID's, SelCal, Paging, ect.) and may also affect Talkgroups. Something to keep in mind if your having trouble.

Also, I noticed your questions were geared toward P25 Trunking. Not sure if the system type is affecting how you approach monitoring it but FYI: VIPER, while using P25 digital voice, is not a P25 trunking system, but rather Type II Smartzone. It also looks to be an Omnilink multizone system with multiple ID's even thought the database here does not list is as such.