Saratoga County - P25

[rwilcox1951]

Hopefully this is being posted in the correct forum. I am (trying to) monitor the Saratoga County NY system. I downloaded the file from RR. I am using a GRE PSR-600. I am in a very fringe area, but am able to occasionally pick them up with a very strong signal. When I do pick them up, it's always the talkgroup "Sheriff 1". This is a fairly large system so it seems odd that the only talkgroup I'm hearing is Sheriff 1. Are there better options for configuring the setup for the PSR-600 in a fringe reception area than the way it downloaded from RR? I've played with different settings but haven't had any better luck. I was hoping there was another member out there with similar experience who could shed some light on the problem. A better antenna would help, but that has to wait until spring. I am encouraged that I am able to hear them at all.

[wtp]

i don't know the whole situation but..
i see they have two systems, which one are you listening to?
also if it is a smart system you will only hear the units on that system
the system keeps track of who is in the area

[rwilcox1951]

Hi. The system I am monitoring is the North Simulcast System. I don't know if it's a Smart System. I am only about 10 miles from the edge of the county, but I'm not sure where the transmitter/tower is from here. I'm probably 40-50 miles from the South Simulcast System. I didn't even try for that one.

[58006]

I am near Northern Saratoga County and the only system that constantly shows up on the display is the Southern system and comes in load and clear.

[rwilcox1951]

I'm NW of Great Sacandaga Lake in southern Hamilton Co. I'll try entering the South system and see what happens. Thanks.

[DaveNF2G]

There are a number of "catches" to monitoring Saratoga County.

The North System generally will become active when a unit is actually using one of the sites that is part of that system. Actually, the South System works in exactly the same way, but most of the county's population - and therefore most of the radio units - are active within the South almost all of the time.

The system is digital simulcast. This means that, when a system is active, more than one site is transmitting on the same frequencies at the same time. This means constant interference. Unless your radio is capable of operating in a simulcast environment like the actual system radios are designed to do, you will not receive the radio traffic very well, if at all. Scanners have a much more difficult time of it.

Digital signal reception is not very tolerant of interference or weak signals. If your scanner loses some bits, then you are likely to hear nothing at all.

[rwilcox1951]

I entered the control channels for the south system a couple of days ago and have heard nothing since. "Analyze" produces no result, even though I get a weak signal breaking squelch. I'll put the control channels back in for the north system. At least I get something once in a while from it. Do you know if the entire county is using the new system or just LE so far?

[SteveC0625]

Originally Posted by rwilcox1951

I entered the control channels for the south system a couple of days ago and have heard nothing since. "Analyze" produces no result, even though I get a weak signal breaking squelch. I'll put the control channels back in for the north system. At least I get something once in a while from it. Do you know if the entire county is using the new system or just LE so far?

AFAIK, Fire and EMS are on the new system as well. When we go over the county line for a major incident, either the FD or EMS hands us one of their 800 MHz portables for operations. We used it extensively last summer at a very large woods fire.

[Jeffrey442]

I'm also not getting anything in the south system.

[Thunderknight]

Originally Posted by Jeffrey442

I'm also not getting anything in the south system.

What scanner and where are you located? The south system is very busy.

[Jeffrey442]

I just purchased the BCD996XLT and programmed it through Radio Reference. I'm assuming that something is wrong with the setting in the scanner or the import from RR. I have a lot to learn with this new scanner...it's a big change from my BC9000XLT. I live near Stillwater and I never had a problem getting the Saratoga County Sheriffs. Thanks for your help.

[DaveNF2G]

You should get good reception in Stillwater from what I've read.

It is helpful if the firmware in your 996XT is the latest (whatever it is now - don't ask me LOL).

Sometimes the problem with the Saratoga system (for a scanner) is too much signal. Try an indoor antenna, if you aren't using one already. You can also try some attenuation to see if that helps.

[KA1RBI]

Originally Posted by DaveNF2G

The system is digital simulcast. This means that, when a system is active, more than one site is transmitting on the same frequencies at the same time. This means constant interference. Unless your radio is capable of operating in a simulcast environment like the actual system radios are designed to do, you will not receive the radio traffic very well, if at all. Scanners have a much more difficult time of it.

Dave is correct.

There is also a writeup here on RR concerning "simulcast digital distortion" but that is full of misinfo and disinfo. Its biggest problem is that it doesn't correctly describe the problem, with the result that scanner owners aren't demanding the mfgr's to add one simple feature that many modern ham rigs already have; a final IF low enough to be processed in DSP.

I know of no scanner that doesn't pass received P25 signals through an hardware FM detector chip [discriminator or PLL] first before the signal is applied to the DSP chip. CQPSK (when simulcast distortion is present) is irrevocably mangled when the signal is passed through FM demodulation, because LSM/CQPSK contains "AM" components [it is not constant magnitude]. The solution is to demodulate CQPSK signals as PSK not as "C4FM" (that is, demodulation at IF).

Another big problem with the RR wiki page is that it fails to mention that anyone with the skill to add a disc tap to a scanner would have the hardware skill to achieve reception on a par with on "actual system radio" [same mod; just different tap point]...

As an example of (yet another) nitpick with the RR wiki article it suggests expensive highly directional yagi antennas as if ordinary whip antennas would not work just as well (within reason of course). Of course if you have no S-meter deflection whatsoever then yes, you may indeed be a good candidate for a yagi. But many folks report no scanner reception even with reasonable signal strength on the meter - those folks are very ill-served by the RR wiki page...

Best Regards

Max

[Chauffeur6]

Originally Posted by KA1RBI

There is also a writeup here on RR concerning "simulcast digital distortion" but that is full of misinfo and disinfo. Its biggest problem is that it doesn't correctly describe the problem, with the result that scanner owners aren't demanding the mfgr's to add one simple feature that many modern ham rigs already have; a final IF low enough to be processed in DSP.

Another big problem with the RR wiki page is that it fails to mention that anyone with the skill to add a disc tap to a scanner would have the hardware skill to achieve reception on a par with on "actual system radio" [same mod; just different tap point]...

As an example of (yet another) nitpick with the RR wiki article it suggests expensive highly directional yagi antennas as if ordinary whip antennas would not work just as well (within reason of course). Of course if you have no S-meter deflection whatsoever then yes, you may indeed be a good candidate for a yagi. But many folks report no scanner reception even with reasonable signal strength on the meter - those folks are very ill-served by the RR wiki page...

Best Regards

Max

Any RR member can edit Wiki articles. If the "Simulcast digital distortion" article is truly as flawed as you clearly believe it is, then contribute to it so that the community is better served by your knowledge on the subject.

[KA1RBI]

Originally Posted by Chauffeur6

Any RR member can edit Wiki articles. If the "Simulcast digital distortion" article is truly as flawed as you clearly believe it is, then contribute to it so that the community is better served by your knowledge on the subject.

Been there, done that - it said I did not have permissions.

73

[Chauffeur6]

Originally Posted by KA1RBI

Been there, done that - it said I did not have permissions.

73

You need to log into the Wiki section separately before you can edit anything.

Log in / create account - The RadioReference Wiki

[KA1RBI]

Originally Posted by Chauffeur6

You need to log into the Wiki section separately before you can edit anything.
[/url]

Okay, have done that - added the following to the Additional Resources section at the end...

One individual had several issues with this wiki article as it existed on Jan. 2013. Rather than attempting to rewrite the article, the reader is referred to [1]

which links back to the original post here....

Max

[DaveNF2G]

OK, so where can I find information on the scanner modification that would bring my reception up to par?

[KA1RBI]

Originally Posted by DaveNF2G

OK, so where can I find information on the scanner modification that would bring my reception up to par?

For the PRO-2096 the correct tap point is TP-5. YMMV.

I'd expect you should already know that a series DC-block disc capacitor would be Highly Advisable as well.

Connect the resulting 455 KC IF signal to your favorite SDR :-)

73

Max

[rwilcox1951]

Same subject Saratoga County, NY P25 system. I picked up the County Highway 1 talkgroup this morning as a wildcard. Very good signal. I did modify both high and low thresholds (98-70). Now for my question...can I enter control channels for both systems in the same TSYS?