Scanning on long trips using Full Database and GPS

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donc13

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Sorry put you are short facts and all parks are used state wide so these exist.
Come on man, the coverage area of a system isn't in doubt, but the coverage area of a SITE is. A system is made up of sites. I know for a fact, that the SDS200 only scans SITES that are within the range set via the location range setting in the menu.

I live in Colorado, we have a statewide system, over 100 sites. So the range of the system is 450 miles, but only sites that are within 20 miles of my location are scanned. I know this for a fact as I can see the sites listed as they are scanned.

Now yes, if a radio for from the eastern side of the state drives to the western side of the state associates with a tower (site) near me, then I will hear that eastern system (state patrol) but that has nothing to do with GPS range.
 

buddrousa

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Sorry you refuse to except the facts.
No the state parks do not talk from Nashville to Memphis but are considered on the same license but different sites.
The fact remains it is not what you want to here so you do not except it.
My last post on this with you.
 

phask

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You apparently modified it, I just pulled it from the database, range is 20 to 25 miles for all sites

UHF is line of sight, the curvature of the earth limits line of sight to about 25 miles for any single tower (site) over relatively level ground.

Not TN parks, but Wildlife - 250 miles. This is not unusual. In fact, it's very common for statewide systems I could show you dozens of similar entries.

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phask

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I did say ".. you apparently modified it.." I should have said ".. It is wrong...". For that, I apologize.

I just looked up all western Tennessee trunked sites belonging to the Tennessee Advanced Communications Network (TACN) and all sites show between 15 and 25 miles.

And you and I both know a single UHF site can not cover a 480 mile diameter circle (240 mile range)

Thus.. My original, "show me a 350 mile range on a UHF site and I will show you a lie" is correct... That value is wrong, it's not possible at ground level.

Sites yes, look up talkgroups for that system - many are at 280.

Link - Tennessee Advanced Communications Network (TACN) Trunking System, Various, Multi-State - Scanner Frequencies
 

donc13

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Final comment.

I have zero issues using just the full database, service types and GPS while on trips. I do NOT use any favorites.

My SDS200 only looks for SITES within a 20 mile radius no matter how large an AREA the system (such as Colorado DTRS that covers ALL of Colorado) and it scans quite quickly.

Done
 

KevinC

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I think the point is the way some agencies are structured in the database they have to have a statewide "range". The fix I guess would be to breakdown the individual divisions based on county or region served. If trunked then system-wide TG's would still need the "range" of the complete system of course.

I have the same issue in my state and it sucks when a frequency has a 150 mile range and no PL/DPL/NAC.
 

donc13

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I think the point is the way some agencies are structured in the database they have to have a statewide "range". The fix I guess would be to breakdown the individual divisions based on county or region served. If trunked then system-wide TG's would still need the "range" of the complete system of course.

I have the same issue in my state and it sucks when a frequency has a 150 mile range and no PL/DPL/NAC.
Only speaking of Colorado. Statewide agencies can use their radios anywhere in the state a tower and that radio are associated. Now yes, some towers are "reserved" for specific sets of talkgroups but that's mostly along heavily congested areas... Say, the Colorado Springs to Fort Collins "corridor"

Of course, that's also where the towers are closer together.

But, if say a Fort Collins Police car drove 150 miles South, his radio would continue to provide Fort Collins PD traffic to that car and anyone down there who had that talkgroups programed into their scanner. Obviously ( I hope) that Fort Collins car would not be associated any tower (site) anywhere near Fort Collins, it would be associated with the closest tower that wasn't reserved strictly for local agencies.

And it wouldn't make sense for someone living 150 miles South of Fort Collins to have programmed in the Fort Collins talkgroups.

But a GPS controlled radio, listening to that tower and programmed for law enforcement service type *could* hear it IF it's algorithm heard talkgroup 12345 on the control channel and then looked to see if that was a law enforcement talkgroup within the State of Colorado DTRS system.

I do not know how Uniden sds firmware decides to stop on that talkgroup or not. But I do know for a statewide agency like the State Patrol, it DOES do it.

If a Denver area State Patrol car from Denver drives over to Grand Junction (220 miles away) and that car doesn't switch to the local area talkgroup, I will hear both regions. Whereas normally I only hear the local 3 regions for the state patrol.
 

JoeBearcat

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Show me a fire or police dept (all I listen to) with a 350 mile range on their transmitter sites and I will show you a lie. 🙄

I can describe one: The State of Wherever has a car-to-car channel that is used statewide and Wherever is 350 miles in radius.

No, not any single transmitter will reach that far (generally speaking) but the network of transmitters will.

Now, does any given state have a 350 mile radius? I don't believe so, but that was not the challenge. :)
 

pbecker0127

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I have the same setup. What I do for the times I'm actually driving is I use the GPS and set the range to "0" knowing that it's going to load systems that won't be close to where I am and maybe not be able to hear at all. If I happen to hear something of interest I just lock that channel for a while. If I know where I may be spending some time I program FLs for those areas. Probably won't work for everyone but it does for me.
 

donc13

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I can describe one: The State of Wherever has a car-to-car channel that is used statewide and Wherever is 350 miles in radius.

No, not any single transmitter will reach that far (generally speaking) but the network of transmitters will.

Now, does any given state have a 350 mile radius? I don't believe so, but that was not the challenge. :)
I said "transmitter" and by "lie" I mean an untruth, not anything evil or fraudulent.

I suspect, but don't know, Alaska will have a 350 mile radius.

What would be the purpose of showing the "range" of a SYSTEM. Systems are made of sites (xmiter towers) and individual sites certainly have a range where their signal can be reasonably received. If I am not within reception range of any site within that system, yet am in "range" of that system... Who cares? And finally, where is that system "range" calculated from? Let's take Tennessee, Tennessee is 432 miles wide... East to West, but only 112 miles high North to South. Is the range 216 miles or is it 56 miles? Does it mean anything or matter?

I believe range for a system is a meaningless value.
 

JoeBearcat

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I said "transmitter" and by "lie" I mean an untruth, not anything evil or fraudulent.

I suspect, but don't know, Alaska will have a 350 mile radius.

What would be the purpose of showing the "range" of a SYSTEM. Systems are made of sites (xmiter towers) and individual sites certainly have a range where their signal can be reasonably received. If I am not within reception range of any site within that system, yet am in "range" of that system... Who cares? And finally, where is that system "range" calculated from? Let's take Tennessee, Tennessee is 432 miles wide... East to West, but only 112 miles high North to South. Is the range 216 miles or is it 56 miles? Does it mean anything or matter?

I believe range for a system is a meaningless value.

I guess it depends if you want to hear that user or not.

As for what 'range' means, RR defined that. I believe it loosely comes out to: The range for which the information presented is relevant.

In my example: Wherever PD/FD/AnythingElse.

If you are within range of where they use their car-to-car channel, it would seem to apply.

I also know that some people think range should be the transmitter range. This is not how it is used in this context.

In many cases, the range of Othertown is say 5 miles (city center to the edge of their service area) even if their transmitter covers 25 miles. Again, this is the range where the data is relevant - not the range of a single transmitter.

So, when you look at "range" as "service area where that channel may be used", it starts to make more sense, no?

Oh, and TN would be a range of 216 only if it were less than 1 mile tall. Since it is 110 miles tall, the range would be 242 from the center if I did the math right. (You don't want to cut off the corners)

I didn't make these terms, but I think I have an understanding of them. (Admin please feel free to correct me)
 

Dewey

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And to murky the waters just a little more, but building on your explanation Joe (which I agree), there may be the occasional talkgroup or couple/few talkgroups that should have a crazy range. The example would be if the system has a Citywide or Statewide channel in a true citywide/statewide sense. Using Alaska's 350 miles as an example, if their State Patrol had a "Statewide" channel, that channel should cover the range of all of Alaska. The range for whatever group that channel would reside in would be all of Alaska, but the sites should still have their ranges restricted to the service area for that site. Keep in mind that even in this example, the radio traffic on that channel should only be carried by sites where radios are currently in their service area and affiliated with them (turned to that talkgroup).

EDIT: Reading backwards, I see where you already said this Joe.
 

donc13

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I have the same setup. What I do for the times I'm actually driving is I use the GPS and set the range to "0" knowing that it's going to load systems that won't be close to where I am and maybe not be able to hear at all. If I happen to hear something of interest I just lock that channel for a while. If I know where I may be spending some time I program FLs for those areas. Probably won't work for everyone but it does for me.
I guess it depends if you want to hear that user or not.

As for what 'range' means, RR defined that. I believe it loosely comes out to: The range for which the information presented is relevant.

In my example: Wherever PD/FD/AnythingElse.

If you are within range of where they use their car-to-car channel, it would seem to apply.

I also know that some people think range should be the transmitter range. This is not how it is used in this context.

In many cases, the range of Othertown is say 5 miles (city center to the edge of their service area) even if their transmitter covers 25 miles. Again, this is the range where the data is relevant - not the range of a single transmitter.

So, when you look at "range" as "service area where that channel may be used", it starts to make more sense, no?

Oh, and TN would be a range of 216 only if it were less than 1 mile tall. Since it is 110 miles tall, the range would be 242 from the center if I did the math right. (You don't want to cut off the corners)

I didn't make these terms, but I think I have an understanding of them. (Admin please feel free to correct me)
Joe,

It's still meaningless to apply a range to a system. I listen to police in a city that's 60 miles away, I can do that because the city's PD is on the statewide system and there are sites within 20 miles of me that have cars associated with those sites.

But that brings up a point quite revelant to use of GPS and SDS200 while driving... Which I do.

What is the algorithm (in simple terms) that Uniden uses to determine what systems and sites it will scan as you move about.

I would think (but obvious don't know) that it would build a rectangle (or circle) around me, use my setting for range, find all sites where range intersects with my "rectangle" and scan any sites that carried my selected service types.

Doesn't matter if it's on a statewide system or local system. Thus cars on MyState system are heard as long as a MyState system's site is within my GPS range.


From my own experience, if I am in Colorado, the SDS200 loads ALL statewide sites (100+ towers) but only scans those sites (6 or so) within my GPS range.

Anyway whatever algorithm it's using, it works for me.
 

JoeBearcat

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What is the algorithm (in simple terms) that Uniden uses to determine what systems and sites it will scan as you move about.

I would think (but obvious don't know) that it would build a rectangle (or circle) around me, use my setting for range, find all sites where range intersects with my "rectangle" and scan any sites that carried my selected service types.

Anyway whatever algorithm it's using, it works for me.

The algorithm is: Does your set range in the scanner overlap the range of the Site/Department? If it does it is included.

Four examples:

Your range is 15 miles and the system is 45 miles away with a 25 mile range. You will not scan it. (25+15=40 = you are not within the limit)

Your range is 15 miles and the system is 35 miles away with a 25 mile range. You will scan it. (25+15=40 = you are within the limit)

Your range is 0 miles and the system is 45 miles away with a 25 mile range. You will not scan it. (25+0=25 = you are not within the limit)

Your range is 0 miles and the system is 35 miles away with a 40 mile range. You will scan it. (40+0=40 = you are within the limit)

Basically, set to a 0 mile range the system has to cover where you are. There is a fudge factor because we are dealing with circles and geopolitical areas are almost never circles, but it should come out close. If your range is set to 15 miles, you have to be within 15 miles of the service area of that user.

You set the range in the scanner you want to hear. RR sets the system's service area range (which is different than the RF range). The RF range might be (and probably will be) greater than the service area range. So if you think the service area range is wrong for a Site/Dept, you have to report that to RR. Of course for trunked systems you have cells that may have lower RF range than the service area.

Paul Opitz wrote an article called "Location, location, location" that goes through this very well.
 

hiegtx

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The algorithm is: Does your set range in the scanner overlap the range of the Site/Department? If it does it is included.

Four examples:

Your range is 15 miles and the system is 45 miles away with a 25 mile range. You will not scan it. (25+15=40 = you are not within the limit)

Your range is 15 miles and the system is 35 miles away with a 25 mile range. You will scan it. (25+15=40 = you are within the limit)

Your range is 0 miles and the system is 45 miles away with a 25 mile range. You will not scan it. (25+0=25 = you are not within the limit)

Your range is 0 miles and the system is 35 miles away with a 40 mile range. You will scan it. (40+0=40 = you are within the limit)

Basically, set to a 0 mile range the system has to cover where you are. There is a fudge factor because we are dealing with circles and geopolitical areas are almost never circles, but it should come out close. If your range is set to 15 miles, you have to be within 15 miles of the service area of that user.

You set the range in the scanner you want to hear. RR sets the system's service area range (which is different than the RF range). The RF range might be (and probably will be) greater than the service area range. So if you think the service area range is wrong for a Site/Dept, you have to report that to RR. Of course for trunked systems you have cells that may have lower RF range than the service area.

Paul Opitz wrote an article called "Location, location, location" that goes through this very well.
Here's a link to the 'How it works' article.
How it Works: Location, Location, Location
 

donc13

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The algorithm is: Does your set range in the scanner overlap the range of the Site/Department? If it does it is included.

Four examples:

Your range is 15 miles and the system is 45 miles away with a 25 mile range. You will not scan it. (25+15=40 = you are not within the limit)

Your range is 15 miles and the system is 35 miles away with a 25 mile range. You will scan it. (25+15=40 = you are within the limit)

Your range is 0 miles and the system is 45 miles away with a 25 mile range. You will not scan it. (25+0=25 = you are not within the limit)

Your range is 0 miles and the system is 35 miles away with a 40 mile range. You will scan it. (40+0=40 = you are within the limit)

Basically, set to a 0 mile range the system has to cover where you are. There is a fudge factor because we are dealing with circles and geopolitical areas are almost never circles, but it should come out close. If your range is set to 15 miles, you have to be within 15 miles of the service area of that user.

You set the range in the scanner you want to hear. RR sets the system's service area range (which is different than the RF range). The RF range might be (and probably will be) greater than the service area range. So if you think the service area range is wrong for a Site/Dept, you have to report that to RR. Of course for trunked systems you have cells that may have lower RF range than the service area.

Paul Opitz wrote an article called "Location, location, location" that goes through this very well.
Thank you... That helps.

So, for the system that started this with a 220 mile "range". If I have my range set at 20, then if I am 25 + 220 miles or 245 miles from the "center" of that system, it will not be scanned even if there is a site in that system that has a range of 30 miles and is only 10 miles from my location.

Correct?
 
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