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[KE2BJW]

When I am listening to my local dispatch how come some dispatchers sound like there voice is compress and digital on a Analog system is this like new thing cause I do notice some sound so compress it almost sounds just as good as digital I was wondering if it's a new thing for digital compress audio on analog or are they running something digital in the back bone and this is just a a general question is about all.

Thanks

 

[Whiskey3JMC]

Probably an analog rebroadcast (or patch?) of a digital talkgroup. Hard to determine for sure without agency specifics so we can have a look at the RRDB

 

[KE2BJW]

Probably an analog rebroadcast (or patch?) of a digital talkgroup. Hard to determine for sure without agency specifics so we can have a look at the RRDB

what is a rebroadcast or patch

 

[AK9R]

Don't assume that the radio transmitter and the dispatchers are in the same location with an analog wire between the dispatcher's microphone and the transmitter. They may be located miles apart. In the old days, dedicated Bell wirelines (analog phone lines) were used to connect dispatchers with remote transmitters. These days, the dispatcher's voice is likely to be digitized and sent over an Internet connection to the transmitter.

 

[jtwalker]

what is a rebroadcast or patch

An interconnection between two different types of radio systems/technologies. A person talking on a radio on system A is also heard by persons on system B as if original person were connected directly to system A.

 

[KE2BJW]

Don't assume that the radio transmitter and the dispatchers are in the same location with an analog wire between the dispatcher's microphone and the transmitter. They may be located miles apart. In the old days, dedicated Bell wirelines (analog phone lines) were used to connect dispatchers with remote transmitters. These days, the dispatcher's voice is likely to be digitized and sent over an Internet connection to the transmitter.

wow that is so neat so basically it's VOIP - ROIP remotely and this is cool and my local dispatcher are on a analog system but this is so cool knowing they can digitized compress and send over VOIP on a analog system.

 

[AK9R]

Here's an example of dispatchers and transmitters being very remote from each other.

The CSX railroad has consolidated all of their dispatchers in a centralized dispatching center in Jacksonville, Florida. Likewise, the Union Pacific Railroad has their dispatching center in Omaha, Nebraska, and BNSF railroad has their dispatching center in Fort Worth, Texas. Yet, these dispatchers are able to communicate with train crews over VHF analog radio in the far reaches of their respective railroad systems. It's all done with remote transmitters that are connected to the dispatching centers via the Internet.

I monitor the local CSX frequencies in central Indiana. When a crew operating on local rails wants to talk to the dispatcher, they send a DTMF tone from their radio. That alerts the dispatcher that someone is calling. The dispatcher then selects the remote base that the tone is coming from and answers "CSX Dispatcher Jacksonville".

 

[KE2BJW]

Here's an example of dispatchers and transmitters being very remote from each other.

The CSX railroad has consolidated all of their dispatchers in a centralized dispatching center in Jacksonville, Florida. Likewise, the Union Pacific Railroad has their dispatching center in Omaha, Nebraska, and BNSF railroad has their dispatching center in Fort Worth, Texas. Yet, these dispatchers are able to communicate with train crews over VHF analog radio in the far reaches of their respective railroad systems. It's all done with remote transmitters that are connected to the dispatching centers via the Internet.

I monitor the local CSX frequencies in central Indiana. When a crew operating on local rails wants to talk to the dispatcher, they send a DTMF tone from their radio. That alerts the dispatcher that someone is calling. The dispatcher then selects the remote base that the tone is coming from and answers "CSX Dispatcher Jacksonville".

ok I understand thanks for the information and this is very cool stuff