Laird 800 MHz Stubby Antenna on G5

[troymail]

This only applies if it’s not a simulcast system?

No, not necessarily.

If I am monitoring a system with multiple sites but they simulcast, all sites broadcast the same traffic correct?

No, not necessarily. "Simulcast" is per site. Traffic on one "site" doesn't always get carried on other sites. Some talkgroups could be transient on some site and some talkgroups could even be prohibited on some sites. It's all up to the system administrators, how the system is configured, and where the units on the state are located/which "site" they affiliate with at any given time. Conversely, some talkgroups (fir example a fire dispatch talkgroup) might be forced onto all sites.

EDIT: actually, sorry - "simulcast" depends upon the context of the question. That last line about a fire dispatch talkgroup might be considered another form of "simulcast" in a different context.

I’m still learning the programming of these systems

We all are! :lol:

 

[KM4WLV]

No, not necessarily.

No, not necessarily. "Simulcast" is per site. Traffic on one "site" doesn't always get carried on other sites. Some talkgroups could be transient on some site and some talkgroups could even be prohibited on some sites. It's all up to the system administrators, how the system is configured, and where the units on the state are located/which "site" they affiliate with at any given time. Conversely, some talkgroups (fir example a fire dispatch talkgroup) might be forced onto all sites.

EDIT: actually, sorry - "simulcast" depends upon the context of the question. That last line about a fire dispatch talkgroup might be considered another form of "simulcast" in a different context.


We all are! :lol:

Simulcast means that the same traffic is carried across all sites, that's why it's called simulcast. Our system here in Rowan County is simulcast. It uses the same frequencies at each site and all traffic is transmitted at each site regardless of talkgroup/radio affiliations at that site. That's why so many are using the G4/5 series pagers to monitor these. UASI is also a simulcast system. These are the systems that you experience Linear Simulcast Distortion on when trying to monitor using a digital scanner.

VIPER isn't considered a simulcast system because the traffic is site dependent. Traffic that is carried on one site may or may not be broadcast on another unless there is a radio affiliated with that site on that TG. VIPER and other systems like it are multicast systems. This is why you can monitor VIPER using regular digital scanner and not experience the Linear Simulcast Distortion issues you get with other systems.

 

[troymail]

Simulcast means that the same traffic is carried across all sites, that's why it's called simulcast. Our system here in Rowan County is simulcast. It uses the same frequencies at each site and all traffic is transmitted at each site regardless of talkgroup/radio affiliations at that site. That's why so many are using the G4/5 series pagers to monitor these. UASI is also a simulcast system. These are the systems that you experience Linear Simulcast Distortion on when trying to monitor using a digital scanner.

VIPER isn't considered a simulcast system because the traffic is site dependent. Traffic that is carried on one site may or may not be broadcast on another unless there is a radio affiliated with that site on that TG. VIPER and other systems like it are multicast systems. This is why you can monitor VIPER using regular digital scanner and not experience the Linear Simulcast Distortion issues you get with other systems.

I'm well aware of the difference between simulcast and non-simulcast systems and sites.

There is some confusion when using lots of terms - "simulcast" and "site" are two of them.

You're using the term "site" to identify towers/transmitter sites in a simulcast system. In that context, you are correct that all talkgroups are carried on all "sites" (towers) because they are all using the exact same frequencies. Rowan county is a "single site" simulcast system. A simulcast system has to have at least 2 towers transmitting on the same frequencies to be considered a "simulcast" system/site.

However, in "multi-site" systems - such as UASI (which has 7 "sites"), each "site" has it's own set of frequencies. Each "tower" or transmitter in that "site" uses the same frequencies. Talkgroups on each of these "sites" typically are not carried on all "sites". Not all "sites" in a "multi-site" system have to be simulcast. They can be all "simulcast", all "stand-alone", or a mixture of simulcast and non-simulcast.

However, I agree, NC VIPER "sites" - to my knowledge, are not "simulcast" sites and they have a single tower/transmitter per "site".

 

[KM4WLV]

I'm well aware of the difference between simulcast and non-simulcast systems and sites.

There is some confusion when using lots of terms - "simulcast" and "site" are two of them.

You're using the term "site" to identify towers/transmitter sites in a simulcast system. In that context, you are correct that all talkgroups are carried on all "sites" (towers) because they are all using the exact same frequencies. Rowan county is a "single site" simulcast system. A simulcast system has to have at least 2 towers transmitting on the same frequencies to be considered a "simulcast" system/site.

However, in "multi-site" systems - such as UASI (which has 7 "sites"), each "site" has it's own set of frequencies. Each "tower" or transmitter in that "site" uses the same frequencies. Talkgroups on each of these "sites" typically are not carried on all "sites". Not all "sites" in a "multi-site" system have to be simulcast. They can be all "simulcast", all "stand-alone", or a mixture of simulcast and non-simulcast.

However, I agree, NC VIPER "sites" - to my knowledge, are not "simulcast" sites and they have a single tower/transmitter per "site".

Troy, please don't take what I said earlier as a jab at you or me trying to imply that you don't/didn't understand the difference in the types of systems/sites, etc. I may be reading to much into it........... I'm sure you understand the difference and if you thought I was please implying you didn't accept my apologies. I've seen other posts & comments you've made in other threads so I know you're fairly well versed in the various systems and their operations. I've been

Rowan County is a Simulcast system in the way it does in fact have more than one site of our four total that transmits on the same frequency at the same time. When monitoring our system from a digital scanner ours seems to struggle more with LSD that some others because of this issue. Myself and our system manager talk on a regular basis, and when our P25 was nearing completion I stayed up on the information because at one time its original plan was to be a "regular" SmartZone system initially but with it being so hard to get licenses for new freqs these days, especially in the 7/800 range with so many systems operating in this band. I've also confirmed this by getting in range of each site and monitoring that. I also did some "drive testing" while it was still in the testing phase before our cutover. I've also been a daily user since we did the cutover to the P25 system from our old SmartNet II system.

But like I said I agree with your post above except for what you mentioned about the Salisbury-Rowan system. The system during normal operation does "recycle"/transmit on the same frequencies at each site which is why I noted above that ours struggles a lot more with the LSD problem. That's also why in the database here on RR there is only 1 under the Site column.

Hopefully this helps clarify what I meant. I'm not saying other systems aren't configured in the way you mentioned. Lord knows these days systems have so many different ways of being configured. I just wanted to make sure that how our system works here.





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[troymail]

Daniel - no problem at all for me. I think we're all just trying to help users that want to understand the differences in the systems and how that might affect their ability to use a scanner or other radio if they buy one or why it isn't working if they already have it.

I'm seeing alot of frustrated folks lately who buy a radio and it doesn't work for one reason or another - encryption, simulcast, and/or just a lack of understanding of how the systems and radios actually work. I'm seeing alot of "I'm sending this thing back today" lately but that's probably always been there...

As with most technology and general discussions, some of the terms can lead more to confusion than making it easier to understand.

In terms of the information in the RRDB, the terms "system" and "site" - at least when it comes to trunk systems - is pretty standard. I think we should try to avoid using a term like "site" to mean other than the RRDB usage of the term without making the context of a term like that clear if being used in a different context.

Obviously, you and I and others are only trying to help - we just have to make it as clear as possible for those who don't understand this technology as well as we (think we) know...