Crazy question

TedTobias

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I live in the Manatee Sarasota county which is simulcast why cant I just program the simulcast Info in and scan off that. Just a thought.

Thanks
Theodore
 

hiegtx

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I live in the Manatee Sarasota county which is simulcast why cant I just program the simulcast Info in and scan off that. Just a thought.

Thanks
Theodore
Can you clarify what you're asking?

Obviously, to listen to the system, you have to program in the simulcast sites. But even though it's listed only once in the database, the Simulcast is actually a collection of sites, all using the exact same frequencies, and carrying exactly the same conversation on any given frequency or talkgroup, at the same time, on all of the individual transmit sites that are part of the simulcast system.
1601089420290.png
Each of the balloon markers represents a transmitter tower location.
1601089528317.png
If, for example, if Manatee County Fire Dispatch, TGID 201, is assigned frequency 854.9875 by the system controller, the exact same voice traffic is being broadcast from each of the site locations shown by balloon markers, all at the same time.
1601090269500.png
You cannot program the scanner to use only one of those sites. They are all configured the same. The problem, for scanners, is that the signals from the various sites arrive at the scanner's antenna, at various times depending on te distance to each. While that time differential is extremely small, it is out of sync enough to impair how the scanner can receive the system. While the SDS series scanners are designed to deal with that factor, the older scanner models are not always able to correctly decode the signals. That results in either garbled reception, or no reception at all, unless you are using an SDS series scanner, one of the Unication pagers, or an actual professional radio (like field units carry).
Simulcast digital distortion - The RadioReference Wiki
 

TedTobias

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All I can say is wow I just leaned a huge amount of information Very impressed!!

Thanks So Much I think I just learned amazing information with such detail!

Theodore
 

mancow

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What specifically do you need to know? Being simulcast you only have one set of frequencies unlike non simulcast where you might need to add various sites.
 

kruser

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Obviously, to listen to the system, you have to program in the simulcast sites. But even though it's listed only once in the database, the Simulcast is actually a collection of sites, all using the exact same frequencies, and carrying exactly the same conversation on any given frequency or talkgroup, at the same time, on all of the individual transmit sites that are part of the simulcast system.
Great Post Steve.

Your post in its entirety should be merged into an existing Simulcast wiki page or a new one.
This was a great way of explaining Simulcast for those that may not understand how it works in today's complex radio systems.
 

Ubbe

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That results in either garbled reception, or no reception at all, unless you are using an SDS series scanner, one of the Unication pagers, or an actual professional radio (like field units carry).
Can't you also use a $10 dongle and any of the programs for PC or a Raspberry Pie or the new BluTail mobile scanner?

/Ubbe
 

hiegtx

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Can't you also use a $10 dongle and any of the programs for PC or a Raspberry Pie or the new BluTail mobile scanner?

/Ubbe
Ubbe,
I'm aware of the fact that you can monitor a simulcast system using one or more of the SDR dongles, and with the appropriate software package. I have not gotten into using the dongles as yet, but eventually I may, if for nothing else than as a tool to document newly discovered DMR & NXDN systems in my area. If I'm reading the posts correctly, for some of the available software packages it takes two or more dongles to track a system correctly. But for at least one of the programs, it can be done using a single device. But the SDR 'solution' does not lend itself to portability. Having to drag a laptop or Raspberry Pie out to your vehicle, and get everything correctly connected, in order to monitor a system when mobile would not be a good way to start a trip for many people.

While portability is not an issue if only using at home or other fixed location, not everyone has the time to successfully learn & implement a new way of listening. Also, they may not have the patience to work through everything that needs to be done, nor the computer savvy to work with the commands necessary to make an SDR setup work acceptably.

The Blue Tail option has some of the same disadvantages (to some people, though not all) of the SDR dongles in that setup & correct operation depends on a series of commands to instruct the BT as to what you want it to do. It does require a PC for at least that part of the process, though, if I'm reading the information correctly, once it's up and running it can be disconnected from a computer. Again, if I read the documentation correctly, it can deal with conventional (non-trunked) frequencies, but only if specific commands are 'entered via the console'. I presume that means using a PC with the software for the BT installed. Apparently, to power the BT when portable, you'd use one of the USB power bricks such as are used to charge tablets & cell phones.
 
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