Alabama Highway Patrol, Troop G. Not hearing most patrol car transmissions, but hearing dispatch

[threeofnine]

Over the last two or three days I have noticed I am hearing, Alabama Highway Patrol Troop G, dispatch but rarely hear transmissions from individual troopers. Usually when this happens it means they are just too far away. However, today while getting launch one performed a traffic stop right across the street from where I was. I heard dispatch loud and clear but nothing from the Trooper so half the conversation was missing. There is a live stream from Troop G and I notice its the exact same situation on the live stream. What is going on here? I can still hear both dispatch and Troopers when listening to Troop F.

I notice that Troop G, but not Troop F, is listed as also being part of the Alabama Interoperable Radio System (AIRS) Alabama Interoperable Radio System (AIRS) Trunking System, Varies, Alabama but as a VHF patch. Is it possible they are moving over to P25 and this is why I am not hearing the transmissions? If that is the case, why am I hearing dispatch?

 

[threeofnine]

Edit. Something I forgot to mention. For the last few days radio reception has been pretty poor. Not just on my scanner, as I've heard dispatch give the 10 code for unclear transmissions and complain about reception multiple times.

 

[IcomIcR20]

I am not sure if this is applicable to your situation, but I will note that in the case of Troop D, there are times when I can hear the dispatcher but not the units. To elaborate, I monitor the Opelika AHP repeater, but sometimes things get patched together and I can hear dispatches for Montgomery and Alexander City as well, but I do not hear the units in those areas since they are operating on their respective repeaters in those cities. I only hear a unit if they are in the Lee County area and are using the Opelika repeater.

As for AHP using AIRS, that is entirely possible. I routinely hear AHP units operating natively on the MMCCD P25 system, so it would not surprise me if they use AIRS in other parts of the state. Troopers typically have the ability to access a number of systems. For instance, in Lee County I hear them on their own repeater, MMCCD, and even the Lee County Sheriff dispatch frequency on occasion.

I have also noted internment poor audio from the dispatcher at times over the past few months. The signal strength is fine, but the best way I can describe it is "stuttering" in the audio.

 

[KE4ZNR]

To elaborate, I monitor the Opelika AHP repeater, but sometimes things get patched together and I can hear dispatches for Montgomery and Alexander City as well, but I do not hear the units in those areas since they are operating on their respective repeaters in those cities. I only hear a unit if they are in the Lee County area and are using the Opelika repeater.

In the dispatcher world this is called a "Multi-Select" and happens when a dispatcher wants to transmit on several channels/TGs at once but have the units reply on their individual TGs. It is different than a patch.
Multi-select: One way outbound dispatcher across several channels/TGs where units in the field only hear traffic on their respective TGs.
Patch: channels/TGs actually patched together and everyone can hear each others radio traffic.

 

[IcomIcR20]

In the dispatcher world this is called a "Multi-Select" and happens when a dispatcher wants to transmit on several channels/TGs at once but have the units reply on their individual TGs. It is different than a patch.
Multi-select: One way outbound dispatcher across several channels/TGs where units in the field only hear traffic on their respective TGs.
Patch: channels/TGs actually patched together and everyone can hear each others radio traffic.

Thanks, Marshall. I knew I was not using the best terminology there. Appreciate the clarification!