St. Louis Area Trunked Emergency Radio (St. Charles County)

[rbritton1201]

I discovered that the S.L.A.T.E.R. System seems to be set up a little differently than MOSWIN, at least it appears that way to me where St. Charles County is concerned. I speculated that I could remove all but the control channels and secondary control channels from the list of frequencies for the S.L.A.T.E.R. sites for St. Charles County, which is typical of what you can do with respect to MOSWIN sites, thereby removing frequencies that are virtually unused in order to increase the speed of the scanning sequence by not having to scan over frequencies that are virtually unused.

But, what I found is that if I only programmed the control channels and secondary control channels into my SDS200 for St. Charles County, I missed a huge amount of radio traffic. In fact, I received little or no traffic via St. Charles County agencies when only the control channels and secondary channels were programmed into the scanner, and I would frequently miss the second half of conversations when I did hear traffic, as the system assigns from the full list of random frequencies as the various agencies key-up. I noticed that the S.LA.T.E.R. system in St Charles County uses at least (10) or more of the frequencies listed in RR, on a routine basis. The various agencies in St. Charles County share all these frequencies, and the system utilizes all of them to carry the full compliment of traffic on the S.LA.T.E.R. system in St. Charles County.

I don't know if this is that same scenario with S.L.A.T.E.R. in St. Louis County and/or Jefferson County, as they're "E-cryptonited," and monitoring those agencies is virtually impossible as a result. I would assume it's the same setup in St. Louis County and Jefferson County, in that the S.L.A.T.E.R. system is setup for "Interoperability," and it seems St. Charles County would need to be synchronized with the setup in St. Louis County and/or Jefferson County were St. Charles County to be called upon to assist in the other two Counties.

I did program into the St. Charles County S.L.A.T.E.R. system the St. Charles County Interoperability Talk Groups, but I'm not sure they're not just basically taking up space, and slowing down the scanning sequence. I don't know whether the Interoperability Talk Groups indicated for St. Charles County in Sentinel are for use just within St. Charles County, or whether they're intended to be used in conjunction with activities involving St. Louis County and Jefferson County, or both. If I thought the Interoperability Talk Groups were just for use in St. Charles County, I would keep them in programming. But, if they're setup within S.L.A.T.E.R. to be used in conjunction with assisting St. Louis County and/or Jeffco only, I would probably delete them from the scanning sequence. Anybody know?

The other difference I noticed is that there does not always seem to be a signal indicator when the various agencies in St. Charles County key-up, depending on the frequency their signal is assigned to by the S.L.A.T.E.R. system when they do key up. Sometimes there's a signal indicator, sometimes not. I notice signal indicators appear when the system assigns them a control channel to key-up on, and sometimes when they key-up on a non-control channel, there is a signal indicator, sometimes not. I don't believe I've ever noticed where they have keyed-up on a secondary control channel, and have no idea if they're even in use.

So, as Kruser has mentioned several times, I agree that the signal indicator is very unreliable on the SDS scanners, and I don't believe the omission of the signal indicator when transmissions are received is inherent in the S.L.A.T.E.R system itself, but it is an anomaly within the Uniden SDS product line.

 

[scanman1958]

You do not have to program all the channels in the St Charles system. Your scanner will work just fine with the control and alternate channels programmed. All of the other frequencies are voice only channels and the control channels assign them as needed. I am not sure but if you program all the voice channels you 'might' get signals on them but it will be completely random. It is absolutely possible that a single radio conversation could be assigned many different voice channels especially if there is a pause in talking. The computer stops using the voice channel because it doesn't need it any more. When a person involved in the same conversation keys up again the control channel assigns another voice channel (frequency) and it continues. It is also perfectly possible that if another conversation takes place 'before' the one you are monitoring starts up again you will not hear your conversation as long as the scanner is stuck on the new one.

As we have been saying, clear as mud.

 

[kruser]

That's all true scanman for the most part!
The thing that would stop it from working that way though would be no or a poor signal from the control channel. Then I think the scanner will scan through all the programmed frequencies looking for a control channel signal. I'm pretty sure it will decode an active voice channel when doing this also if it scans thru one but only as long as the voice channels signal is good enough. I could be wrong on this.
Basically I think the scanner reverts to scanning the voice channels programmed but more like a bunch of frequencies programmed as digital in a conventional fashion. Some data would probably still display like the talkgroup and UID when it does this.

You could always prove the scanner can work this way by removing the control channels from a P25 system with a good signal and then seeing if the scanner does still stop on voice channels. It would probably be worth doing the test of a system with a decent signal quality as I could be way off thinking it will revert to scanning the voice channels like a conventional entry if the control channel is missing.
It's also possible the active control channel is being decoded but only some of the time and that's what causes the scanner to occasionally tune to an active voice channel. I can definitely see this happening with a weak signal level.

@rbritton1201 Scan speed should not be slowed down if all frequencies are programmed as long as you have a decent control channel signal.
Same goes for programming rarely used talkgroups. Those will not slow down scanning of a P25 trunked system at all as the scanner is going to watch the control channel for any talkgroup it sees regardless if it's programmed in the scanner or not.

 

[rbritton1201]

LOL, yeah, this whole scenario with these scanners is usually clear as mud! I think in my case, due to my location being in Union, and the distance from the sites in St. Charles County, my SDS200 scanner may be skipping over the control channels, and only randomly landing on them as poor propagation conditions dictate.

So, as a result of a suggestion from Kruser, I've changed the site delay period from a delay of 2 seconds to 5 seconds. I think it improved the ability of the scanner to have an opportunity to lock onto the control channel more frequently than before, but it think it's still skipping over the control channel once in a while.

Even at that, I'm receiving voice transmissions via the various agencies, and there's continuity to the conversations as the scanner scans. So, from my perspective, I think I'm actually hearing pretty much what I expect to hear, but it doesn't seem to be the perfection I'm used to hearing, just a hunch on my part, as you don't know what you may be missing if you can't hear what you may be missing anyway. But, the conversations seem to have continuity with respect to each voice session based on what they're saying. I notice that I may hear one transmission from an agency on one frequency, and the reply may be on the same frequency, or it may be on another of the frequencies. But, they're loud and clear transmissions, just like you would expect if you were getting full deflection of the signal indicator, which is not often the case. I don't always receive any deflection of the signal indicator, very weird!

As we have been saying, clear as mud.

 

[rbritton1201]

What I noticed is that when I only entered the control and secondary channels into the scanner, I heard nothing. When I entered the entire lists of the frequencies back into the scanner, then I received what sounds like normal traffic with continuity of conversation. It sounds like I'm hearing both sides of the conversation pretty well, loud and clear, but the transmissions are not always on the control channel, but on one of the other channels from the entire list of frequencies for St. Charles County agencies within Sentinel. The scanner does randomly land on the control channel, and sometimes there's a signal indicator, and sometimes not. Sometimes, the signal indicator will show up with pretty decent deflection, then in the middle of the transmission, the signal indicator will completely disappear. It must be as you suggested, maybe just a fluctuation in the ability of the scanner to receive signals. I also notice that the D-Error and the RSSI values don't sometimes reflect the good strength of the signal audio I'm receiving, both at times when I'm getting full deflection of the signal indicator, versus times when the signal indicator first shows up, but then completely disapprears during the transmission.

You could always prove the scanner can work this way by removing the control channels from a P25 system

 

[rbritton1201]

I've been using the SDS200 to formulate the programming for my BCD436HP, which after making a few adjustments in Sentinel, I can virtually duplicate the programming that I have in the SDS200, and apply it to the BCD436HP. The SDS200 is good for this kind of experimentation because I have elevated antennas in the attic here at the base station that will at least pull in some signals from St. Charles County, and other outlying areas, all be those signals are apparently iffy at times.

I can receive nothing over the BCD436HP here in Union from St. Charles County, or any of the other outlying areas, such as Phelps County, Crawford County, Lincoln County, etc...using the rubber duck antenna. But, with the SDS200 programmed for outlying agencies, I am able to see if the program is working with the SDS200, since I can pull in signals from those outlying areas using my elevated attic antenna system. Then, if the BCD436HP is programmed right, I should be able to monitor those outlying agencies, and know that before I get to those outlying areas I'll have an expectation that the BCD436HP will work properly. So, having the SDS200 programmed with St. Charles County at least provides me with some feedback as to whether I have the BCD436HP programmed to receive while I'm up in St. Charles County area with the BCD436HP.

I'm up in the O'Fallon area relatively often, hence my desire to take the BCD436HP up that way, and monitor O'Fallon and other St. Charles County agencies. Otherwise, I wouldn't really want to include St. Charles County in the mix, since I would otherwise be only interested in monitoring the area around where I live, in Franklin County. The other outlying agencies I have programmed into the SDS200 right now are for experimentation, as I formulate programming with the BCD436HP in mind, in order to receive those outlying agencies when I might be taking a trip to adjoining counties, etc...

 

[llzel]

Following along, but I have a unication G4. I live in STLCO but finally got around to program in St Charles Slater TGID's. SC city, county, O'Fallon, St Peter's. When I included STLCO north, south and St Charles sites I couldn't receive any St Charles TG's. I set up another system with just the St Charles site 1-003 and can receive all of St Charles SLATER TG's from University City.

 

[rbritton1201]

I'm in Union, Missouri, and we're probably about the same distance from about O'Fallon, about the middle of St. Charles County. I don't know exactly where the control channel towers are, but there might be one closer to you than to me, which might make it a little easier to snag signal.

I made some changes to my SDS200...

With respect to St. Louis County and Jefferson County, since they're "e-cryptonited," I've chosen to eliminate them from programming completely. But, I am still wondering how the "Interoperational" frequencies and "talk groups" in St.Charles County interface with S.L.A.T.E.R. in the "e-cryptonited" venues, if at all.

I've programmed the SDS200 so that I have a Favorites List for each of the agencies in St. Charles County under one Favorites List heading entitled "St. Charles County," and I've also programmed the individual agencies in St. Charles County under their own individual Favorites Lists by agency name.

I did that so that if I'm up in O'Fallon, for example, I can just select O'Fallon PD, and not have to listen in on transmissions that are generally just routine stuff covering up more interesting activity that might be occurring in O'Fallon, where I may be in closer proximity to the action. Sometimes, having too much in a Favorites List can clog things up, and you miss half of what you want to listen to if the good stuff is happening in whichever venue you're focused on.

So, I divided the various agencies up into their own Favorites Lists. But, in the event there's some kind of "inter-agency" serious stuff going on, I can dial in my Favorites List that has all the St. Charles County agencies in it, and follow the action occurring between venues.

At Kruser's suggestion, I changed the sites over to "Narrow Wide" from "Global" on O'Fallon PD, St. Charles County PD, St Charles City PD, Lake St. Louis PD, Wentzville PD, St. Peters PD, and the Foristell/New Melle PD Favorites Lists. I also changed the S.L.A.T.E.R. site delay within Sentinel from 2 seconds to 5 seconds. It seems like it might have also made a difference capturing the site ID on the screen of the SDS200 scanner.

I've also been using the SDS200 to formulate the programming for my BCD436HP, which after making a few adjustments in Sentinel, I can virtually duplicate the programming that I have in the SDS200, and apply it to the BCD436HP. The SDS200 is good for this kind of experimentation because I have elevated antennas in the attic here at the base station that will at least pull in some signals from St. Charles County, and other outlying areas.

I'm confident now that if I take the BCD436HP up into St. Charles County, I'm reasonably sure that I'll be able to pick up the control channels up there without any problem. But, from Union, Missouri, I can't pickup anything in St. Charles County with the BCD436HP, and it's rubber duck antenna. I even connected it to one of my Discone antennas in the attic, but got nothing, whereas I get good performane with the SDS200 connected to a Discone. I suspect it might perform better if it had the same site adjustments that are on the SDS200, where I can change from "Global" to "Wide Narrow," etc...But, the BCD436HP doesn't appear to have those same site adjustments.

Following along, but I have a unication G4. I live in STLCO but finally got around to program in St Charles Slater TGID's. SC city, county, O'Fallon, St Peter's. When I included STLCO north, south and St Charles sites I couldn't receive any St Charles TG's. I set up another system with just the St Charles site 1-003 and can receive all of St Charles SLATER TG's from University City.

 

[nick1427d]

You typically won’t receive St Louis County talkgroups via St Charles or the Jefferson Co sites and Vice Versa. SLATER is not a statewide system so they only allow certain talkgroups on certain sites.
In short, don’t program St. Louis county talkgroups under a st Charles or Jefferson Co site.
In regards to the interops, they get used during protests and things like that but it’s rare. They are usually assigned ahead of time. Day to day not a chance. The Training channels, which are shared by all, get used on occasion by fire departments during training scenarios.

 

[rbritton1201]

I went up toward St. Charles County yesterday, and was around Chesterfield Mall. I was disappointed because I was expecting to receive some radio traffic, and at least control channel signal transmissions on my BCD436HP, but got nothing. Of course, I was using a rubber duck antenna, but a decent one, a Remtronix REM-842B VHF/UHF/ BNC 800 MHz. Triband Scanner Antenna. I was expecting that from Chesterfield Mall, just across the river from O'fallon, I would have expected to have at least seen a signal bar or two, but nothing. MOSWIN (MSHP) was loud and clear, almost fully signal bar deflections off the Weldon Spring tower while in Chesterfield.

Is this kind of performance typical of the SLATER system? I can receive SLATER on my BCD536HP scanner based in Union off a Discone antenna in my attic, and that's using an excessively long RG8/X coax cable run around 100 feet from scanner to antenna. Now, understandably, it's barely decent reception, but decent enough to receive fully readable transmissions between Union and O'fallon, but signal deflection indicators vary between about 1/2 bar to 2 bars on the readout, depending on the day, conditions, etc...

The BCD436HP programming is the same as the programming in the BCD536HP, so I don't think there's any programming anomaly causing the poor reception on the BCD436HP.

So, today, I hooked up the BCD436HP to all three of the Discones in the attic to test out the reception quality from Union, and results were inconclusive. The BCD436HP didn't seem to pick up anything in St. Charles County from Union. Two of the Discones have a 100' run of RG8/X coax, and the other Discone has about a 65' run of RG213/U. I tried all three ntennas, but didn't notice any difference, all three antennas were dead through the BCD436HP. Now, of course, today's conditions (snowy etc...) are really lousy, and that could be contributing to the poor performance that resulted from today's testing. But, the BCD536HP connected to the RG8/X cable is still receiving signals from St. Charles County, even today, with the lousy conditions, and it's also probably the worst case scenario with respect to line loss (100' of RG8/X).

Of course, reception using the BCD436HP when monitoring Franklin County agencies, MSHP, Washington PD, etc...is perfectly fiine...

I do notice that the signals coming from Fire/EMS in St. Charles County on my BCD536HP seem to always be just a little stronger than the reception from the other towers. They're all using the same control channel, so I'm not sure why I would experience better signal reception off the Fire/EMS control channel than the Law Enforcement towers.

Anyway, this discrepancy with respect to signal reception has me wondering if the BCD436HP has a sufficiently substandard receiver in it compared to the BCD536HP to account for the anomaly with respect to reception when I'm right at Chesterfield Mall. I thought they were supposed to have the same specs.

 

[rbritton1201]

So, I had an opportunity to take my BCD436HP up to St. Charles County area today. I'm used to seeing continual signal off of specific towers via the MOSWIN system, and don't have experience with how the S.L.A.T.E.R. towers might manifest themselves on the scanner's readout when control channels are active. I didn't notice any constant control channel signals on the various Favorites Lists I had programmed into the scanner for each of the agencies in St. Charles County, unless I was receiving signals from one of those agencies. Then, yes, the scanner seemed to lock onto that agency, and displayed a constant control channel signal whether I was receiving a voice transmission or not. As a different agency transmitted, then the control channel would exhibit control channel signal indicators on that particular agency. It seemed kind of confusing watching the control channel signals as they came through via various agencies, not like MOSWIN, where you can actually lock onto a tower and see a constant control channel signal indicator.

I assume it has something to do with the SIMULCAST function of the S.L.A.T.E.R. system. l assume the various towers within the S.L.A.T.E.R. system transmit simultaneously (SIMULCAST?), and the closest towers are what I see on the scanner's readout when one of the agencies transmits using their respective talk groups. I did not experience any significant interference as transmissions were received. I think that my positive experience with respect to the reception of S.L.A.T.E.R. towers is probably due to the various agencies not transmitting simultaneously. If radio traffic between various agencies were more simultaneous and transmissions from various agencies were more prolific, I assume those simultaneous (SIMULCAST) broadcasts from those agencies might cause what sounds like intermodulation distortion, a common complaint with respect to SIMULCAST broadcasts if monitoring, unless you're using a Uniden SDS100 or a Uniden SDS200, which are designed to decipher SIMULCAST transmissions. The BCD436HP isn't really designed to handle SIMULCAST transmissions, but I didn't have too much of a problem within a jurisdiction like St. Charles County, a County that is comparatively small versus other large city jurisdictions where I would suspect SIMULCAST transmissions would compete with one another, causing what I assume would sound like intermodulation distortion on my BCD436HP. Do I have that about right?

 

[rbritton1201]

I also noticed last night that on my BCD536HP in the shack here in Union, Missouri, which has all the same programming as the BCD436HP with respect to St. Charles County agencies, that a transmission from a control channel is being consistently received corresponding with each of the St. Charles County agencies I have programmed into individual Favorites Lists, all be it only about one signal bar is seen for each agency as it scans over the St. Charles County SL.A.T.E.R. Favorite Lists. The transmissions are all readable, even though I would like to improve the signal reception a bit, or would I?

If the SIMULCAST towers in St. Charles County have a tendency to create an intermodulation condition as they simultaneously transmit on their control channel frequency, then perhaps a weaker signal is actually preferable in my case, provided I am receiving readable transmissions, which the BCD536HP appears to be doing without any interruption in transmission, no clipping, no garbled distortion, etc... The one signal bar I'm receiving with respect to signal strength might indicate that I am only picking up one of the St. Charles County S.L.A.T.E.R. towers from here in Union, since I am only receiving one signal bar on the readout, probably because St. Charles County is so far away from me.

By my only picking up one of the St. Charles County S.L.A.T.E.R. towers from here in Union, would that mitigate the intermodulation effects of having several towers SIMULCASTING simultaneously were I up in St. Charles County with my BCD436HP? I only speculate that reception off of one S.L.A.T.E.R. tower would be beneficial in my case because neither the BCD436HP or the BCD536HP are designed to handle SIMULCAST transmissions off the various towers in St. Charles County, and intermodulation distortion would be more likely if I am up in St. Charles County with my BC436HP, which isn't designed to handle SIMULCAST transmissions.

If that be the case, then if I monitor my BCD536HP via my cell phone feed, originating from the BCD536HP based out of Union, I'm more likely to receive signals without any intermodulation distortion via my cell phone feed versus my being right in the middle of St. Charles County with my BCD436HP scanner.

 

[kruser]

Yes, being a fair distance away from a simulcast system such as SLATER can have it's benefits in reducing or eliminating LSM.
Your theory is correct that you are likely only receiving a signal from one of that systems towers so you should not have any LSM problems.
You don't always get lucky though and sometimes you may still pickup two of the towers for a simulcast system depending on where those towers are located.

I depend upon a far distance working in my favor when I can get a signal from the St Clair County, IL Starcom site. That site has a lot of towers and LSM issues for those monitoring in or near the county but when I get a signal, I'm usually fortunate and only get signal from one of the tower locations. Of course I'm only lucky when good propagation of 7/800 MHz signals is occurring!

Visit this page FCC Callsign WQTK503 (ST. CHARLES COUNTY GOVERNMENT) at RadiorReference and it should show you a map of all the tower sites that makeup the SLATER St Charles County system.
On that page, you can click on the callsign near the top and it will take you to the actual license page at the FCC site. Sometimes you can get a little better info from the FCC site for the tower locations but what RR shows is usually good enough.

 

[rbritton1201]

Hi Kruser,

I guess I'm beginning to understand how these systems work, finally, LOL! Thanks for the link! Looking at the positioning of the St. Charles County S.L.A.T.E.R. towers, it may be the tower that I'm receiving is #2, 500 Schluersburg Road in Augusta. As I recall, that topography is pretty well elevated in the Augusta area. I assume they would locate the tower in a well elevated location. I'll look for the tower next time I'm over that way. I guess there's no way to tell from the display on the BCD536HP that would reveal that tower #2 is the one I'm receiving. The licensing says the site is licensed to Francis Howell School District and St. Charles County. I assume they can enroll whatever talk groups on that site that they want to, both for Law Enforcement and the School District.

Yes, being a fair distance away from a simulcast system such as SLATER can have it's benefits in reducing or eliminating LSM.
Your theory is correct that you are likely only receiving a signal from one of that systems towers so you should not have any LSM problems.
You don't always get lucky though and sometimes you may still pickup two of the towers for a simulcast system depending on where those towers are located.

I depend upon a far distance working in my favor when I can get a signal from the St Clair County, IL Starcom site. That site has a lot of towers and LSM issues for those monitoring in or near the county but when I get a signal, I'm usually fortunate and only get signal from one of the tower locations. Of course I'm only lucky when good propagation of 7/800 MHz signals is occurring!

Visit this page FCC Callsign WQTK503 (ST. CHARLES COUNTY GOVERNMENT) at RadiorReference and it should show you a map of all the tower sites that makeup the SLATER St Charles County system.
On that page, you can click on the callsign near the top and it will take you to the actual license page at the FCC site. Sometimes you can get a little better info from the FCC site for the tower locations but what RR shows is usually good enough.

 

[kruser]

Hi Kruser,

I guess I'm beginning to understand how these systems work, finally, LOL! Thanks for the link! Looking at the positioning of the St. Charles County S.L.A.T.E.R. towers, it may be the tower that I'm receiving is #2, off Schluersburg Road in Augusta. As I recall, that topography is pretty well elevated in the Augusta area. I assume they would locate the tower in a well elevated location. I'll look for the tower next time I'm over that way. I guess there's no way to tell from the display on the BCD536HP that would reveal that tower #2 is the one I'm receiving.

Yep, simulcast trunked systems can be a challenge to learn about for sure.
It's a whole different world compared to our good old and simple analog days!

Scanners or even actual subscriber radios can't discern which actual tower you are receiving a signal from as they all appear as one signal to the scanner.
The techs may have a way to tell which tower they are looking at on a service monitor possibly but I don't know that for a fact. I think I may have read that it's possible for a tech in either the Industry Discussion or Motorola forum a while back but I could be imagining I read that.

I agree that tower site 2 is your likely signal source into Union but sometimes a building or even trees in the summer months can block the signal from the obvious site but in your case, I think site 2 is the one going by distance alone to your home QTH.
Yes, they do usually install the sites tower at high elevation areas unless they just need coverage to fill in a signal gap.
I can't say I've ever seen them use any low elevation sites on the SLATER system but then I can't say I've driven around each of the counties and found the actual tower sites either!

 

[rbritton1201]

Well, as you may know, I'm planning to put the DPD Productions Omni-X antenna into the attic, hoping to improve overall reception of all the bands it's designed for. But, it might actually end up being detrimental to receiving S.L.A.T.E.R. signals off tower #2, assuming that is the tower I'm receiving is the #2 tower, were the trees to leaf out, etc...

I'm at a standstill erecting the Omni-X until the weather breaks, which might be pretty soon, at least for a few days! I hope that whatever reception performance I might realize once the Omni-X is installed that it doesn't screw up my being at kind of "sweet spot" where I'm located as it relates to the LSM factor. But, as you point out, even the trees leafing out might effect my reception of that tower this summer, assuming that is the tower I'm receiving.

In looking at the map of towers, I just can't imagine it would be any of the others, they just seem too far away, although with respect to MOSWIN, I'm picking up that Weldon Spring tower pretty well, three bars of signal here in Union. But, it seems that these S.L.A.T.E.R. towers project less power than the MOSWIN towers, but I have no direct knowledge of that. I think the MOSWIN Weldon Spring tower is off Hwy 94 near the Francis Howell High School. So, the reception I get here in Union off that tower is pretty remarkable. I attribute it to power output versus elevation, but that's purely speculation on my part, taking into consideration, of course, that elevation is also a very important factor.

With some of these MOSWIN sites, they seem to be on some pretty impressively tall and professionally constructed towers, whereas, for example, with respect to Washington 700, all evidence points to the big blue water tower at Hwy. 47 and Hwy.100. Just as I did some research on Washington 700 site, I'll keep the Schluersburg Road S.L.A.T.E.R. site on my agenda in an effort to try to find it, and check it out.

...trees in the summer months can block the signal from the obvious site but in your case, I think site 2 is the one going by distance alone to your home QTH.