Erie County P25 System

terryho

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I have similar problems with city sites living here in lake city, I have tried different threshold settings, multiple antennas, no antennas and everything in between. Sometimes it’s not too bad and other times it’s worse! County site will not give you Erie Fire tac channels or Millcreek tac channels they seem to be on the city sites. I attribute most of the problems to location and simulcast issues. Would a sds200 work better I don’t know? I am also trying sdrtrunk Software with a single usb dongle. And am able to hear city sites just fine! Not bad for $25 hardware! As the software developed and gets better it will be a cheap way to listen.
 

maus92

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I have similar problems with city sites living here in lake city, I have tried different threshold settings, multiple antennas, no antennas and everything in between. Sometimes it’s not too bad and other times it’s worse! County site will not give you Erie Fire tac channels or Millcreek tac channels they seem to be on the city sites. I attribute most of the problems to location and simulcast issues. Would a sds200 work better I don’t know? I am also trying sdrtrunk Software with a single usb dongle. And am able to hear city sites just fine! Not bad for $25 hardware! As the software developed and gets better it will be a cheap way to listen.
If you have the technical ability and computer gear to spare, free/low cost software and a $25 dongle or two are cost efficient solutions that work really well using 1/4 wave aka simple antennas.
 

Railbender

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Has anyone having a problem used the tools in the radio to help identify it? Yesterday I was sitting in my backyard with my 436 using the factory rubber duck. I put the Rural site in analyze, zero signal. Came inside and connected it to the Larsen UHF antenna on the mast and got a useable 60 to 80% signal same using the discone. I repeated that this morning using the duck, factory whip and a Diamond RH77CA outside. Walking around the house on one side I got what may have been a usable signal. Went to the attic, 2 1/2 story, and got what was probably a usable signal. BTW the Unication G3 never gave me less than 3 of 4 bars anywhere and worked fine in all locations. As I said above a radio is only as good as the antenna connected to it.
 

maus92

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The Unication radio is designed to receive the digital modulation used by P25 systems, and has the ability to mitigate the multipath effects that are commonly experienced with simulcast reception - like users in Erie County are experiencing. The 436 and other older receivers are not. The experience you just described proves it.

A reading assignment.:Simulcast Distortion - The RadioReference Wiki
 
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Railbender

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If you are not receiving a usable signal from any tower you wont have any simulcast distortion to worry about.
 

maus92

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When two or more tower's transmissions are being received simultaneously (essentially "interfering" with each other,) the radio will not produce a usable message if using that radio is not specifically designed to receive the signalling and extract the all the data in the proper order with as few errors as possible. This often presents as a low or fluctuating RSSI - or even no signal - indication on non-optimized receivers.
 
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Railbender

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How do explain the fact that the same 436 that did not work with the rubber duck is now sitting beside the SDS200, with both connected to the mast mount Larsen UHF antenna through the multiplexer, both working equally as well as the G3. The G3 is there as a control. Due to the present firmware limitations of the G3 it is on the "difficult" Rural site only. I also run a 536 on the discone with no problems.
 

maus92

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Some people are lucky wrt their monitoring location. When a neighboring county replaced their SmartZone system with an ASTRO P25 P1 system, people went crazy when their HP-2 and 436/536 could no longer receive comms reliably. Some found that moving the radio to a different room within their home improved their reception - or even a few feet. Others were totally deaf anywhere near their house. Outdoor / elevated antennas didn't help. What did help was buying a proper receiver, using basically the same antennas as before, and comms were restored.

In my office situation, I am lucky to be located near a member tower of a simulcast cell - about .5 miles. That one tower site essentially overpowers simulcast signals from any other member tower (the next closest site is about 6 miles away,) thus my 536 has no issues with reception - using the stock antenna or a quarter wave magnet mount stuck to a metal railing next to my desk. Taking that same radio mobile using a Moto 3dB antenna mounted on the roof, reception of the same system varied tremendously depending on location. You could literally watch the RSSI bars bounce around from full to nothing (which is an indication of multipathing,) while my G5 didn't miss a transmission - sitting in the cupholder of a F150. When the 536 was replaced with a SDS200, its performance matched the G5. It's the radio.
 

Railbender

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If it were a simulcast distortion problem Scnrfrq and I should see it on the Metro site as we are surrounded my Metro towers the same with Terryho on the Rural site. That is not the case. The site for our respective area it is fine. The problem is that we are on the fringe for the other site and it requires a good antenna to receive it, a rubber duck or whip isn't up to the task.
 

maus92

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I believe Scnfrq lives within Cell A (I think this is what is referred to by you as "Metro" or "Urban" by RRDB) and has at least 3 member towers sites more or less equidistant to his listening location - not good for a non-optimized radio as I stated before. This assumes he lives in the middle of Millcreek Township. If he could clarify his location to a 100 block or nearby intersection, that would also be helpful. I *believe* the logical design of the system hosts Millcreek-related TGs on Cell A most of the time unless a subscriber has affiliated with Cell B for some reason.

I did read the consultant's report that mentions that (some?) sites are not producing the ERP assumed in the system design, but that probably affects the more rural areas of the system's footprint in Cell B (Countywide.)

Can you explain why the Unication works well with a tiny stub antenna?
 

Railbender

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I suggest you look at the FCC license for each transmitter site and plot the azimuth and beadwidth. Just being close does not necessarily mean it is transmitting in your direction. The Metro site is Erie and Millcreek. It carries all talk groups for those areas plus dispatch talk groups for the Rural site. The Rural site is just the opposite.

The Unication plus the issued Kenwood radios are professional grade equipment and work to those expectations. Consumer grade scanners could be built to that level for a price. People complained about the price of the SDS100/200. Quality isn't cheap.

People are free to play with their rubber ducks and whips chasing your mythical simulcast distortion on this system or do what I did, based on the first hand experience you lack, put up a good antenna and listen to it.:giggle:
 

maus92

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Your argument supports what I've been saying - it's the radio.

I have all site plotted using FCC data - all I need is location data from the user.
 

scnrfrq

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My location is just west of W.38th and Buckthorn. I tried using just the County site and avoiding the Urban site. I got no signal at all with the County and no reception. The Urban site shows 4 or 5 bars, and I hear most TG's. Overall reception with both sites active seems to vary some from day to day. My 536's on the 2nd floor sound ok, but the one on the first floor has me adjusting the telescoping antenna a lot. I have it extended all the way now and it helps some. Still considering an SDS200, but all the problems are scaring me away (loud hum, dispaly issues, etc.)
 

Railbender

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Your argument supports what I've been saying - it's the radio.

I have all site plotted using FCC data - all I need is location data from the user.
A radio is only as good as the antenna you have connected to it. Put a good antenna on a 436 or 536 and it does fine. I've shown that with the 436 the last two days. With the duck or whip it is deaf on the rural site. Put the UHF or discone on it and is equal to the SDS200 and G3.
 

maus92

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Here's the quick and dirty data plot wrt the closest tower sites to your location:

Cell A (Urban Simulcast) sites
Fairview VFD: 4.1 miles @ 260°
Erie DPS: 4.6 miles @ 126°
Hilltop: 5.1 miles @ 72°
Hamot Hospital: 6.4 miles @ 42°

Cell B (Countywide) sites
Lake Erie Comm Park: 9.8 miles @ 250°
Sharp Road: 10.8 miles @ 145°
Loop Road: 13.6 miles @ 110°

As you can see by the attached image and measurements above, you are located well within the service area of the Cell A simulcast site. In fact, you are well within the expected operational radius of 4 Cell A tower sites, which is generally accepted to be 8-12 miles for C4FM and CQPSK sites. You should have excellent reception using a portable on hip subscriber radio, even inside residential construction. A consumer grade radio could work well IF you were close to one Cell A tower site, and the rest were much farther away, but this is not the case for you - you have 4 sites within 6 miles. I would definitely suspect "simulcast distortion" to be an issue for you.

However, you are definitely on the edge of the practical range of Cell B tower sites. The closest tower is almost 10 miles away, and would be a challenge to receive reliably indoors even with a subscriber radio. This explains why you have difficulting receiving Cell B from your location.

Weather conditions / temperature inversions / winds often play havoc with reception - sometimes in positive ways, but mostly not. I imagine that the Erie system will not be formally accepted until after the spring when foliage is full (and when they add a few new tower sites.)
 

maus92

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A radio is only as good as the antenna you have connected to it. Put a good antenna on a 436 or 536 and it does fine. I've shown that with the 436 the last two days. With the duck or whip it is deaf on the rural site. Put the UHF or discone on it and is equal to the SDS200 and G3.
The last thing scnrfrq needs is a better antenna - he actually has too much signal for his radio. A Yagi aimed NW *might* help by attenuating multipath interference from other member sites of Cell A.
 

scnrfrq

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Here's the quick and dirty data plot wrt the closest tower sites to your location:

Cell A (Urban Simulcast) sites
Fairview VFD: 4.1 miles @ 260°
Erie DPS: 4.6 miles @ 126°
Hilltop: 5.1 miles @ 72°
Hamot Hospital: 6.4 miles @ 42°

Cell B (Countywide) sites
Lake Erie Comm Park: 9.8 miles @ 250°
Sharp Road: 10.8 miles @ 145°
Loop Road: 13.6 miles @ 110°

As you can see by the attached image and measurements above, you are located well within the service area of the Cell A simulcast site. In fact, you are well within the expected operational radius of 4 Cell A tower sites, which is generally accepted to be 8-12 miles for C4FM and CQPSK sites. You should have excellent reception using a portable on hip subscriber radio, even inside residential construction. A consumer grade radio could work well IF you were close to one Cell A tower site, and the rest were much farther away, but this is not the case for you - you have 4 sites within 6 miles. I would definitely suspect "simulcast distortion" to be an issue for you.

However, you are definitely on the edge of the practical range of Cell B tower sites. The closest tower is almost 10 miles away, and would be a challenge to receive reliably indoors even with a subscriber radio. This explains why you have difficulting receiving Cell B from your location.

Weather conditions / temperature inversions / winds often play havoc with reception - sometimes in positive ways, but mostly not. I imagine that the Erie system will not be formally accepted until after the spring when foliage is full (and when they add a few new tower sites.)
What do the varying colors for the towers mean? Can you specify which are Cell A and which are Cell B?

Also, would an SDS200 do a lot better than a 536, or only marginally?
 

maus92

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The Yagi *could* also help with reception of Cell B. The Lake Erie Community Park site is conveniently in line with Fairview VFD site associated with Cell A
 

maus92

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What do the varying colors for the towers mean? Can you specify which are Cell A and which are Cell B?

Also, would an SDS200 do a lot better than a 536, or only marginally?
The circle colors denote logical Zones (I think that's how I set it up.) The Zones don't matter to a scanner user. The color of the site names denotes the simulcast cell: Green is Cell A (Urban Simulcast) and yellow is Cell B (Countywide Simulcast.) I *believe* the blue is for a shared site (both Cells A and B) but I cannot remember why I did that - I'd have to review the FCC data, and Erie's consultant did some *weird* licencing.

As far as the SDS is concerned - or a Unication G3 - I'd expect a marked improvement in your situation. The "faults" of the SDS200 are way overblown by people who frankly have unreasonable expectations. I own 2 of these radios - they are fine, but then again I use these as tools in either in a mobile office environment - I don't sleep with them.
 
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Railbender

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I fail to understand your thinking. 436 with a duck or whip is deaf on the rural site. With a good antenna it works fine.

I thought you plotted from the FCC data? Check the DPS Flower RD radiation direction. Fairview VFD is also a Rural site as is Hamot.;
 
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