Tri-Com

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flydream777

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Anybody know why Tri-Com is dispatching police on the F-3 freq (470.6125) instead of F-1? It has been this way for about a week now.
 

bakechad

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Flydream,

I have been wondering that as well. They may be having problems. Even on the alternate they are using, I have heard some strange stuff. Early Tuesday morning the F-3 channel had a loud screeching noise being broadcast and they temporarily switched back to F-1. Later that day they went back to the F-3. Very strange.

Chad
 

epdexplorer

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Yeah, i've been wondering that too. They did use F-1 (Primary) for a call recently.... hmm...
 

RBMTS

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Back when I lived in St. Charles 10 years ago, Tricom would move the dispatch to .6125 due channel interference. There was a another agency in south Cook county (can't remember exactly what PD) that was also on 470.9375. The repeater signal was so strong that it was competing with Tricom's repeater output causing receiving problems for mobile / portable units. I'm sure it played havoc with the repeater input as well. So they would switch to the .6125 to that did not have interference. At least this was the story I received from a LEO friend. Try turning off the CTCSS receive on your scanner to see if you can hear the other agency.
 

bakechad

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As of this morning they are back on primary again.

The key is to scan all Tricom frequencies all the time.
 

flydream777

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The other agency using 470.9375 is E-Com, which is in Homewood I believe. I have heard some background interference in the past but I thought the CTCSS normally cut it out.
 

N9JIG

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While not sure if that was the issue with Tri-Com's use of the alternate channel, even with PL interference from outside sources can be an issue. When conditions are just right we will get hetrodyne noise from a repeater located 40 miles away on out T-Band repeater, we use 192.8 PL and the other repeater uses 146.2.

There could also have been a technical fault with the main channel and they may then have been using the alternate until the main channel could be repaired.
 

timmay911

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I used to be a high school intern there... so I have a few insights....

No idea why they went over to Ch 3, but it does happen on occasion - probably tinkering with stuff.

I do know that they have heard a department down in Tennessee (unknown which one exactly) when the weather is just right on Ch 1. Could be what Rich was talking about I guess?

Let me know if ya'll want any other information in general about Tricom??
 

N9JIG

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Can't be Tennesee, they use 470.9375 and there are no users of T-Band in TN, it is only used in select states.

The only other licenses in the area on 470.9375 is the Country Club Hills/Hazel Crest area.



I used to be a high school intern there... so I have a few insights.... No idea why they went over to Ch 3, but it does happen on occasion - probably tinkering with stuff. I do know that they have heard a department down in Tennessee (unknown which one exactly) when the weather is just right on Ch 1. Could be what Rich was talking about I guess?

Let me know if ya'll want any other information in general about Tricom??
 

evilbrad

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6125

tri com will goto 6125 during radio repairs trouble etc. while back they were on there while some radio work was being done. this was back when the 471.100 rptr was being added

kyu
 

pjbgeneva

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PD Dispatch Silence?

This past week I notice that 470.9375 seems silent, while 470.6125 is in use but only by one PD at a time. Last nite it was St. Charles, and the nite before it was Batavia. Geneva PD not heard at all. A couple of years ago when TriCom moved from Geneva to new facility in St. Charles they upgraded to a digital system, but transmissions seemed to still be all analog. Has this changed? Is a new dispatch freq in use for PD? If digital, is it decodable with an Apco 25 scanner?
 

chgomonitor

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470.6125

Tri-Com, Northbrook and some other agency's mobile data terminal traffic make this a very troubled frequency. I listen to Northbrook here and I frequently hear either of the others getting into their receive sites when their mobiles are transmitting, especially at the ends of transmissions. Plenty of buzzing hetrodyning, too. What a mess.

Oddly, I still remember the days when users checked to see if the frequency was busy prior to transmitting, LOL.

Happy Scanning! - Ted
 

bakechad

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I've been listening to Tri-com (all known frequencies) for the last five hours and all I have heard are St. Charles calls. There have been no Batavia or Geneva calls at all. On a Friday night there is normally a ton of activity. Also, there have been no fire calls on any of the known frequencies for the last five hours.

Then I started scanning up and down the bands and can't find any trace of Geneva or Batavia. They have disappeared. Possible they went digital? If so where and what type of system? Why would St. Charles be left behind?

Very disturbing since I just bought another analog scanner today.
 

pjbgeneva

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Police Activity

I have monitored TriCom nightly for about an hour every night this week. Police calls of only Batavia one night, then only St Charles another night, then St Charles and Geneva both on another night, etc. However, the level of activity is very minimal. No actual dispatches are ever heard, just units checking in with TriCom dispatch once in a while. They were supposedly getting "digital" equipment over 2 years ago, but always seemed to continue to use analog. There was a period even before that when they first got MDT's in all their cars that they did a lot of traffic on those, but gradually turned back to more (but not all) analog voice I would guess as being more convenient and safer for the officers. (I've heard this logic stated other places, so assume it applies here too).

The recent situation of no traffic at all, and then from only one or maybe two PD's stumps me though! And the change was very sudden too. This needs more checking by someone with more knowledge and time to do more scanning than I'm able to do.
 

N9JIG

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If they aren't found on any of the four UHF freqs (as listed below, from the CARMA Profile) then I suspect that they are using MDT's for the majority of the traffic. It could be that they upgraded the CAD system to provide more capabilities for mobile messaging and silent dispatch.

470.9375 162.2 F1 Police Dispatch (F2 Talk-around)
470.6125 162.2 F3 Alternate (F4 Talk-around)
471.1000 94.8 F5 Special Events/Details (F6 Talk-around)
471.2750 71.9 F7 Special Events (F8 Talk-around)
 

pjbgeneva

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Further Activity Update

Thanks to N9JIG for the freq info. Yes, I've had those in my scanner for a very long time. At present, the only active one seems to be 470.6125. This past Sat nite, activity there was all three PD's (Geneva, St. Charles, Batavia) and call volume was pretty high. Sunday, still the same, but much less call volume. I think the MDT theory is probably right. As I mentioned earlier, when they first got them a few years ago they "went silent" like this for a while too.

If anything more develops, I will post it here. I monitor TriCom usually every evening, and more during storms, etc.
 
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