CoMIRS Worcester Simulcast Settings Help

[Gunner_Ed]

Hello. I live in southern Worcester county and should be able to receive the CoMIRS system on my BCD496HP, but so far no luck. I pulled down the system from the current Sentinel DB and also tried the RR import. Both data sets have the system set as "P25 Trunk", but I read this is now a Phase II/TDMA system? What is the correct setting for the Worcester simulcast? Any other settings I need to verify?

Thanks,
/Ed

 

[johnrugg]

Hello. I live in southern Worcester county and should be able to receive the CoMIRS system on my BCD496HP, but so far no luck. I pulled down the system from the current Sentinel DB and also tried the RR import. Both data sets have the system set as "P25 Trunk", but I read this is now a Phase II/TDMA system? What is the correct setting for the Worcester simulcast? Any other settings I need to verify?

Thanks,
/Ed

Unless you are within about 5 miles of Worcester to the south, you likely won’t receive the system. If you’re on a hill, maybe. You’re also at a disadvantage because the BCD series does not have the proper receiver for the linear simulcast system that Worcester is. You would need to upgrade to the SDS line.

John

 

[garys]

The SDS scanners definitely do better on LSM systems, but the x36HP scanners can do okay. That of course depends on location, antenna, and other factors. The system appears to be optimized for reception in the greater Worcester area as if a unit goes outside the coverage area of the Worcester sites, it can operate on the MSP owned sites.

 

[Gunner_Ed]

Thank you both for your responses... I was hoping this "coverage map" was accurate:

Commonwealth Of Massachusetts Interoperable Radio System (CoMIRS) Site: Worcester Simulcast

Commonwealth Of Massachusetts Interoperable Radio System (CoMIRS) Site: Worcester Simulcast Details

www.radioreference.com

 

[garys]

I think that is very optimistic.

 

[nikronzo]

Unless you are within about 5 miles of Worcester to the south, you likely won’t receive the system. If you’re on a hill, maybe. You’re also at a disadvantage because the BCD series does not have the proper receiver for the linear simulcast system that Worcester is. You would need to upgrade to the SDS line.

John

johnrugg is correct, unless you are in the city or in a suburb that borders the city, you will have trouble receiving the system, it does transmit relatively well to the south and east of the city but the north and west is poor.
When the EDACS site was up on asnebumskit hill, there was fantastic coverage across the county like the W1BIM repeater. But now the three sites are green hill park, Worcester airport, and southwest cutoff simulcast towers. From what I understand, Motorola mapped the CoMIRS system in Worcester to work in the city and just in the city.

 

[StoliRaz]

Thank you both for your responses... I was hoping this "coverage map" was accurate:

Commonwealth Of Massachusetts Interoperable Radio System (CoMIRS) Site: Worcester Simulcast

Commonwealth Of Massachusetts Interoperable Radio System (CoMIRS) Site: Worcester Simulcast Details

www.radioreference.com

I live on the edge of that coverage area and get exactly jack squat from Worcester. It's B.S.

 

[Gunner_Ed]

Thanks again to all! I run a local feed for the Uxbridge area (incl. MSP Troop C today) and was just trying to get ahead of the eventual CoMIRS migration... Oh well.

 

[cg]

When the system goes digital, you would get P25 coverage where you get analog coverage now. So if you are getting a signal that allows you to hear MSP now, you would still hear them after the conversion. Once the conversion is done, would WFD/WPD coverage be allowed onto the other sites outside the city? That would be a administrative decision rather than a coverage issue.
I do see that the FCC map is much smaller than the RR map:

ULS License - PubSafty/SpecEmer/PubSaftyNtlPlan,806-817/851-862MHz,Trunked License - WPAR399 - WORCESTER, CITY OF - Locations Summary

 

[garys]

In addition to cg's excellent post above, it's good to remember that if a Worcester unit goes outside the coverage area of the Worcester campus system, they'll have access to the wider CoMIRS network. CoMIRS is a single system only in that the agencies on it share the Astro Core. Otherwise they operate and are maintained by their own radio techs and administrators.

 

[W1KNE]

I think that is very optimistic.

It's too optimistic. Thanks to the heads up from another user here, I've reduced it to a more reasonable size. I will go through the other sites later to make sure they make sense.

 

[GTR8000]

And just a reminder that if no one ever submits corrections, nothing will get fixed. If you see a site range that looks "very optimistic", submit your concern and let a dbadmin address it.

 

[W1KNE]

It's too optimistic. Thanks to the heads up from another user here, I've reduced it to a more reasonable size. I will go through the other sites later to make sure they make sense.

There were a few that were set too wide, and one set too far west. All have been tweaked to better match their coverage.

Thanks.

 

[mronn]

You’re also at a disadvantage because the BCD series does not have the proper receiver for the linear simulcast system that Worcester is. You would need to upgrade to the SDS line.

So a BCD992P would not work for Worcester FD?

 

[GTR8000]

So a BCD992P would not work for Worcester FD?

It's all relative and depends on your location and other factors. If you're lucky enough to have full capture of a single subsite of the simulcast cell, the BCD996P2 (assuming that's the model you meant) might work just fine. But if you're getting signal from multiple subsites, you're going to have some issues. The phenomenon referred to as "simulcast distortion" has been discussed countless times over the years on this forum. There is hardware which is specifically designed to handle P25 simulcast (Uniden SDS series, Unication G series pagers, most SDR software capable of decoding P25, etc.), and then there is older hardware like nearly all other scanner brands and models which generally fall short of proper decoding.

 

[mronn]

Oh I see. Thanks for that info. I'm about 4 miles from the Worcester line and 6 miles from Green Hill Park mentioned above. Was thinking about getting a BCD996P2.

 

[KSoucie62]

Helpful info! Thanks all. I have the 996P2 at home and in my vehicle. At home, on the city line, Worcester is loud and clear, same setup in my car and I can loose them while actually in the city. Never knew much about simulcast distortion but this clearly seems to be my issue when mobile. Was hoping not to have to buy an SDS 😏