How much of MOSWIN should I be able to pick up from Joplin, MO?

kj417

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I'm new to scanning and I think maybe I misunderstood how MOSWIN works. I have an "rtl-dsr blog v4" SDR connected to my computer and I'm using sdrtrunk to listen to MOSWIN. I'm mainly interested in listening to law enforcement so that's what I'll be talking about in this post.

I can hear Jasper County, Webb City, Carthage, Newton County, and Neosho police. I'm listening on the 773.31875 MHz frequency for "Joplin 700". Shouldn't I be able to hear more things from across the state? Or is that not what "Statewide Wireless Interoperable Network" means?

I ordered a 2nd rtl-sdr and have both of them working with the sdrtrunk software but I'm still just picking up the same broadcasts I could hear before. I was hoping to pick up Barton County, Dade County, and Lawrence County with this setup. I also haven't heard anything from Diamond or Granby.

Do you think I have my stuff set up wrong or is it not possible to pick up anything else on MOSWIN in my area?
 

wbloss

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Joplin MO
In order for you to hear any Talkgroup on MOSWIN the TG must be "affiliated" with a tower. You are listening to the Joplin 700 tower, located on a 2-Way tower in western Jopin. TGs "affiliate" when two things happen:
- the transmitter (base, mobile, handheld) is near the tower and
- the talkgroup used by the transmitter is allowed to go thru the tower.
For example, Dade County has the Arcola VHF site in it. Units transmitting in Dade County will first be heard and transmitted by Arcola. They may OR MAY NOT be heard by Joplin 700 and may OR MAY NOT be allowed to go thru Joplin 700.
The designers of MOSWIN do not want a site/tower to be overburdened with transmissions by talkgroups that are not needed. But they still want the system to be statewide. So for example each county has a "travel" TG. This allows a deputy from Jasper County to transport a prisoner to Springfield or even Jeff City and still be able to talk with his own department when far away. But he will not hear the regular Jasper County dispatches.
On each MOSWIN site if you click on the details you will see a "neighbor list" - This is a list of adjacent sites that a mobile unit will switch to when moving from one site to another. Generally, but not always, an adjacent site will carry most of the talkgroups from its neighbor.
You may wish to include the Granby site in your list of sites also
MOSWIN and most state systems are complicated beasts!
 

nd5y

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Wichita Falls, TX
In other words your scanner or SDR won't receive anything unless:
1. You are currently receiving a control channel (with a good enough signal that it and the voice channels decodes properly).
2. One or more user radios are affiliated to the site you are currently receiving and using a talkgroup you have programmed.

If the users change channels, turn radios on and off, or are in moving vehicles then what you can and can't hear could change at any time.
 

scanman1958

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You should be able to listen to MOSWIN by programming/monitoring two or three closest MOSWIN sites to you. Check the database for MOSWIN sites near Joplin and use them. I am only guessing here but I believe the Joplin system will be many times busier than than the MOSWIN sites alone. Which could make it hard to receive MSHP traffic. But I have not checked the Joplin site. If it is also a MOSWIN site then maybe the MSHP might not want to affiliate with it because it is so busy. Just a thought.
 

wbloss

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@scanman1958 Joplin does have its own 800MHz P25 TRS, not currently connected to MOSWIN. It is busy but that has no effect on the MOSWIN traffic. In ~2 years Joplin will connect to MOSWIN as ZOne 6 with some new frequencies.
 

chris451rr

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iowa
In order for you to hear any Talkgroup on MOSWIN the TG must be "affiliated" with a tower. You are listening to the Joplin 700 tower, located on a 2-Way tower in western Jopin. TGs "affiliate" when two things happen:
- the transmitter (base, mobile, handheld) is near the tower and
- the talkgroup used by the transmitter is allowed to go thru the tower.
For example, Dade County has the Arcola VHF site in it. Units transmitting in Dade County will first be heard and transmitted by Arcola. They may OR MAY NOT be heard by Joplin 700 and may OR MAY NOT be allowed to go thru Joplin 700.
The designers of MOSWIN do not want a site/tower to be overburdened with transmissions by talkgroups that are not needed. But they still want the system to be statewide. So for example each county has a "travel" TG. This allows a deputy from Jasper County to transport a prisoner to Springfield or even Jeff City and still be able to talk with his own department when far away. But he will not hear the regular Jasper County dispatches.
On each MOSWIN site if you click on the details you will see a "neighbor list" - This is a list of adjacent sites that a mobile unit will switch to when moving from one site to another. Generally, but not always, an adjacent site will carry most of the talkgroups from its neighbor.
You may wish to include the Granby site in your list of sites also
MOSWIN and most state systems are complicated beasts!
How true this is. Here in Iowa traffic is segregated by county. I can't say any other traffic appears, except they have a bunch of patch channels now that come off the state system. Most common an ambulance will run across the county and an odd talkgroup appears.
For this reason I plan to use a gain antenna to get the adjacent 4 counties that use trunking. An FM demod digital scanner doesnt do well on the distant simulcast, but Unitrunker does.
The unitrunker is neutralizing the simulcast hetrodyne note which can be 1-15db at the dips at a few hz. The towers do not use GPS to match the carriers and it drifts a few hz from winter to summer to hot days.
About the only wide area channels are on the statewide system in Iowa and even that is narrowed down to 6 or so regions. So by tuning these other control channels the off system traffic can be captured. When an unusual talkgroup appears it means someone from out of the area has come into the area. I tuned up some big Icom receivers and plan to put a decoder on them for the VHF p25 from 2 or 3 counties away. Those smaller counties don't buy into these simulcast systems it would be too much money and what would be the advantage? They do have P25 and a few with DMR.
 

chris451rr

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If it is Digital Simulcast, they absolutely use GPS. And not just for reference frequency.
Explain the 1-3hz hetrodyne on the carriers then. A gps stabilized time standard of 10 mhz tells you what the frequency error is and its a lot less than 1 hz. For setting up radios you can get a gps stabilized 10mhz reference. The long term stability of the OCXO is 2x10E-10/day in one case I found. Calculating the error freq to 851 mhz it would meander around 0.15hz from perfect, yet I detect 1-5 hz, and
by the way its temerature dependant, as it changes in the winter vs summer. More like a TXCO as the master oscillator then a GPS disiplined oscillator, something else is going on, if every part of the transmit chain is derived from one oscillator. I have not heard of any gps outages but what if something like that happens, who has looked at a block diagram of a harris simulcast?
 

scanman1958

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chris451rr's comment above is part of the reason I am loosing interest in scanning. It used to be fun. Too much to factor in on every aspect of the hobby now. Sorry if it sounds like I am bashing you. I am not. You are well educated and your knowledge is improving our hobby. I things have become too complicated in our hobby. Have a great Mother's Day.
 

hitechRadio

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Dec 23, 2010
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Explain the 1-3hz hetrodyne on the carriers then. A gps stabilized time standard of 10 mhz tells you what the frequency error is and its a lot less than 1 hz. For setting up radios you can get a gps stabilized 10mhz reference. The long term stability of the OCXO is 2x10E-10/day in one case I found. Calculating the error freq to 851 mhz it would meander around 0.15hz from perfect, yet I detect 1-5 hz, and
by the way its temerature dependant, as it changes in the winter vs summer. More like a TXCO as the master oscillator then a GPS disiplined oscillator, something else is going on, if every part of the transmit chain is derived from one oscillator. I have not heard of any gps outages but what if something like that happens, who has looked at a block diagram of a harris simulcast?
I can't speak for Harris simulcast, but no doubt if it is digital simulcast it will have GPS, it must have for launch control.
Motorola Simulcast base stations do not even have an oscillator. The reference is provided the TRAK or similar, which provides the frequency reference and timing for launch of data. They do have a hold over if GPS antenna/s were damaged or sat issue.
 
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