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General Scanning Discussion - For general questions not specific to a model of scanner or general discussion of use of a scanner. Manufacturer specific posts should be directed to the appropriate forums below and location specific posts should go in the appropriate regional forum..

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Old 04-12-2016, 6:54 AM
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Default Simulcast Distortion and Weather Conditions?

Hi All.

I'm one of they many fighting a daily battle with simulcast and my counties P25 system. I've tried all brands of scanners and scanner settings. I've finally had it bashed into my head that the "fix" for simulcast problems is really location, location, location. I live literally dead center of two towers. One is three miles away in one direction and the other is 3 miles away in almost the exact opposite direction. The perfect storm of simulcast distortion. I'm currently using a yagi and have had it pointed towards each tower, slightly away from each tower and even perpendicular away from both towers.

Anyways, the question I have is... Without changing anything, some days I actually get great (well.. better than decent) reception while other days its just horrible. How much do atmospheric conditions play into this? What about terrain?

Thanks.
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Old 04-12-2016, 7:09 AM
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Default Lucky one

Location does make these scanner perform horrible. I myself got lucky as I only receive one tower on STARCOM21 both the Cook and Lake county towers and not centrally located with in. This past weekend I did a patrol centrally within in these towers and my 352p was horrible on receiving with it. I hope these scanner companies someday fix the issue for the people having with these systems. All my base station scanners using the Laird 800 mhz antenna rear of each scanner. I have a off brand in the attic for conventional part of hobby. Yes the weather conditions also is a problem with reception. Good Luck
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Last edited by jpm; 04-12-2016 at 7:17 AM.. Reason: answered weather conditions
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Old 04-12-2016, 1:55 PM
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Yeah simulcast distortion is frustrating.

Terrain probably wouldn't be a day to day influence on reception, since that's a constant thing.

Weather does play a factor in radio wave propogation. Some weather conditions result in improved reception (Thunderstorm ducting) where you hear things not ordinarily heard.

I've seen days where rain makes reception for my local P25 simulcast system better and days where it is worse. My non-technical gut feeling is that it's due to how the rain falls - straight down or at angles (as in raining sideways). The rain may deflect the radio waves owing to their size.
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Old 04-12-2016, 5:58 PM
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Weather conditions that make radio transmissions and propagation worse, will often improve reception on a scanner listening to a simulcast system.

Like using a bad antenna, turning on attenuation, or other similar tricks to reduce reception to a single source rather than simulcast reception of multiple sources, will improve reception on a scanner.

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Old 04-12-2016, 6:26 PM
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The best thing for simulcast distortion is a paint can antenna. With the lid off an empty paint can, insert short antenna connected to coax through the side near the bottom. Listen to control channel in search mode, keep tilting it until you hear no crackling from the tower your trying to avoid
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Old 04-12-2016, 8:34 PM
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Read this:

http://forums.radioreference.com/min...-buster-2.html

Yes, simulcast interferes with radio. Weather interferes with radio. When you have both, you have an ever-changing environment of interference.
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Old 04-13-2016, 3:39 PM
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Read this:

http://forums.radioreference.com/all...d-scanner.html


Quote:
Originally Posted by Voyager View Post

Yes, simulcast interferes with radio.
Don't. Even. Get. Me. Started.

Max
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Old 04-13-2016, 11:09 PM
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So the interference on Motorola radios on a Motorola simulcast P25 system are just figments of everyone's imagination? OK. I guess Motorola has no idea of how to design radios, but Unication (who are largely working off Motorola's designs) does.

Gotcha. Understood.
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Old 04-14-2016, 7:36 AM
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Quote:
Originally Posted by Voyager View Post
So the interference on Motorola radios on a Motorola simulcast P25 system are just figments of everyone's imagination?
What interference are you talking about? On my 15 site 7.14, my subscribers (all 3122 of them) don' experience any interference, or this "simulcast distortion" that scanners suffer from, due to a poor design.

Please elaborate with some factual data. I'll be glad to discuss them with my ST next Tuesday...
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Old 04-14-2016, 1:05 PM
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Really - your system is perfect with never any issues? Why do I find that lacking credibility in the extreme?
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Old 04-14-2016, 3:22 PM
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Quote:
Originally Posted by Voyager View Post
Really - your system is perfect with never any issues? Why do I find that lacking credibility in the extreme?
I don't ever have any issues with a very large (25 county with multiple sites per county) simulcast P25 system that I work with. That's the difference between a scanner and a real radio. They are designed to deal with it.
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Old 04-14-2016, 4:38 PM
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Quote:
Originally Posted by Voyager View Post
Really - your system is perfect with never any issues? Why do I find that lacking credibility in the extreme?
Proper system design, full coverage testing, proactive maintenance - amazing what those things will do. Why do we find you lacking credibility in the extreme?
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Old 04-14-2016, 4:46 PM
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Quote:
Originally Posted by Voyager View Post
Really - your system is perfect with never any issues? Why do I find that lacking credibility in the extreme?
I participated in acceptance testing. I personally drove test over 1/3 of my county with one of our Motorola reps with a "Voyager" kit. Not ONE tile failed in my zone and very very few in the other 3.

I work with my users daily. I monitor voice traffic as well as performance data DAILY.

The FACT is it works superbly. Miles above the 29 year old Smartnet we had. I rarely hear anyone "go digital" and the few times they do, it's a known location deep inside the bowels of a building (like some of our schools) or they were way way outside of the county (like 40 miles).

I have tested EF Johnson VP600/900, Harris XL-200Ps, and now Relm KNG-P800s on my network and guess what:

They all work well with no "simulcast distortion" these turdbox scanners seem to suffer from. Even with **encryption enabled**

Scanners are garbage pail piles of junk on P25 linear simulcast. End of story.
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Old 04-14-2016, 5:43 PM
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Quote:
Originally Posted by MTS2000des View Post
I have tested EF Johnson VP600/900, Harris XL-200Ps, and now Relm KNG-P800s on my network and guess what:

They all work well with no "simulcast distortion" these turdbox scanners seem to suffer from. Even with **encryption enabled**

Scanners are garbage pail piles of junk on P25 linear simulcast. End of story.
LOL @ "turdbox scanners". That just about sums it up. As long as Uniden, Whistler, et al continue to make junk that doesn't PROPERLY AND CORRECTLY decode/demod simulcast, there will be an endless parade of pissed-off scanner users who can't solve their simulcast distortion issues no matter what antenna/location they try.
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Old 04-14-2016, 6:58 PM
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One thing I've noticed about Kansas City's simulcast system is that each voice channel has it's own personality.

With a scanner, each individual voice channel has consistent performance no matter which talk group is steered to it.

They range anywhere from 5 bars/99% decode to totally un-decodable.

When the system is busy, park your scanner on a voice channel and rate it's decode performance.

Do this on each of the voice channel your system uses, then work on the problem child first to see if any improvements can be made.

Using a methodical approach may save you a lot of head banging and you can decide for yourself if anything can be done.
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