Pinellas County P25 Sites

[productionguy85]

As far as SPPD, nomatter what the TG is, if the radio afiliates on Site 5 then the TG will be heard. I am not aware of the Site 4 coverage in St. Pete. IE it may be possible that 1 side of the city uses site 5 instead of site 4. Next, I have also heard the 1F for Fire, and a few others in regards to St. Pete College, however I dont want to submit them, until I am absolutely sure of there use/ location. As far as the FD TGs, the current 1F does not align with the rest of the numbering scheme. If you have noticed, Every difference department/ municipality is it multiples of "10". Since 1F is (DEC) 522, that would make 1A 512 which is odd. Being the first TG of a department, it should be ie 510 or 500. If you get where I'm going?

 

[cabfeegig]

I listen only to site 5 and basically concur with Ngel and get the same thing with no-issues. PCSO Car to car B still seems to be analog (Ridgetcrest).

 

[chief21]

Good Morning All. A question for the group...

After reading this thread (especially the map from ProductionGuy), I am understanding that both the P25 and analog Pinellas "sites" are actually simulcast from multiple locations, with each "site" having its own footprint... some localized and some county-wide. It is my further understanding that both the P25 "site 005" and the Ridgecrest "site" are intended as county-wide coverage.

That said, I can actually see the Pasadena location from where I am and I AM able to receive P25 "site 005" very well (on 851.2000) but I am NOT able to receive a very good signal for the analog "Ridgecrest site" (on 857.1875). Since county Fire Rescue is my primary interest, this is not good.

Is it likely that Pasadena has been removed as a "Ridgecrest site" location, or perhaps the control channel Xmitter at that location is malfunctioning, or perhaps my understanding is not correct???

Comments...? Suggestions...?


-JK

 

[David40]

If you look at the registered locations of the "sites" I believe you will find they are all at the same location. As far as I know all of the transmitters use the same wattage so all should be considered county wide as far as the reach of the signals. All the rest of it is in the software driving the system.

 

[David40]

Also, I should add that I have my scanner set up as two systems for Pinellas. One system is conventional trunking using both the Toytown and Ridgecrest sites, and then the P25 system using all of the rest of the sites. That covers everything I want to listen to. Then it's just a matter of organizing your talkgroups. Because of the limitation of the number of talkgroups on the 396XT I could set up duplicates of those systems and load the extra talkgroups in those systems but I have not found it necessary. Hope that helps

 

[chief21]

Hi David -

Thanks for responding to my questions. I agree with the way you have your scanner set up, but I think you might be confused about the radio system architecture.

The various sites (typically called "systems") that Pinellas County operates use simulcast technology. In simulcast, multiple tower locations (typically called "sites") all transmit on a given frequency at the same time. This approach, which is very common for large radio systems, provides for much improved mobile and portable coverage throughout the system footprint.

As you might imagine, if all the Pinellas systems actually transmitted from only a single location, the system talk-out coverage would be very limited... especially in medium and large buildings and locations distant from the transmit site. The radio system in Broward County, with which I am very familiar, also uses simulcast technology to enhance their county-wide coverage.

In addition, each of the Pinellas systems actually appears to target coverage for certain general areas. For example, the Ridgecrest system sites are scattered throughout the county in order to provide county-wide coverge, while the Toytown system sites appear to favor the St Pete area. If all of the systems provided the exact same coverage county-wide, there would be no real need for separate systems.

In any case, after researching the Pinellas site licenses, it appears that the simulcast transmitters associated with the Ridgecrest system have been removed from the site closest to me, and that is likely why I can no longer receive the Ridgecrest talkgroups as well as I once could. This might be part of the eventual P25 system build-out, since there IS now a transmitter near me (actually several) that are associated with the P25 systems. I guess we'll all have to wait to see how it all shakes out once the changes have stabilized.

In the meantime, apparently I won't be listening to any Fire talkgroups until they switch to P25 or I get a bigger antenna!

-JK

 

[David40]

So this is more complex than one would initially believe. If I understand you correctly, a "site" as defined in Pinellas, is not necessarily a physical location, but a conglomeration of various transmitter locations all transmitting simultanoiusly on the same frequencies assigned to that "site"?
Seems like I found a map of the P25 sites somewhere and it showed the coordinates of all 5 P25"sites" as a location just North of Ulmerton Road. I suppose this was just an arbitrary geographical location to indicate the center of the area covered but not the actual transmitter locations?

 

[chief21]

For fixed transmitters, each one of the lines on the license represents a single frequency and its specific location coordinates. Since the Ulmerton Road site is likely the prime site (and near the center of the county), it probably has transmitters for each of the Pinellas systems (or "sites" as they are called locally). This is probably also true of other well-positioned sites.

It DOES get confusing. The only way to get a true picture of the system architecture is to list all of the transmitters and plot them on a map. To make things a bit easier, one could do this using just the control frequencies for each of the different systems. That's how I finally realized that the frequencies associated with the Ridgecrest system were no longer at the tower site near my location.