996XT and ORION Simulcast sites

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SCPD

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I think my 996XT took a crap. It will not decode any audio from the Douglas county simulcast. The DATA will flash on the screen and the signal meter will go from full scale to nothing, both happen within a second. It is not a 800Mhz, trunking or digital issue. The scanner works fine on Sarpy's system decodes Cass's P25 and OPPD's control channels are strong with no drop out. I did drive to Washington county tonight to see if the problem only happens on Douglas county's sites. Unfortunately that same happens with Washington county. The scanner worked fine until Wednesday. The scanner did work fine after the firmware update to display the RID.
It's not a programming issue. I use the same file with my 396XT and that works fine.
So does anyone have any ideas?
 

realgeo

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I think my 996XT took a crap. It will not decode any audio from the Douglas county simulcast. The DATA will flash on the screen and the signal meter will go from full scale to nothing, both happen within a second. It is not a 800Mhz, trunking or digital issue. The scanner works fine on Sarpy's system decodes Cass's P25 and OPPD's control channels are strong with no drop out. I did drive to Washington county tonight to see if the problem only happens on Douglas county's sites. Unfortunately that same happens with Washington county. The scanner worked fine until Wednesday. The scanner did work fine after the firmware update to display the RID.
It's not a programming issue. I use the same file with my 396XT and that works fine.
So does anyone have any ideas?
Very odd.

Try programming a Conventional system that happens to contains only the voice channels for the "ORIN" system. This would be a way to confirm your P25 decoding capabilities, revealing possibly a problem with the P25 trunking portion of the scanner, even though the decoding and trunking parts are basically the same thing!

Haven't had any problems with my 396XT or the new firmware.

73s
 

SCPD

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It started working fine again. I think the cold temps had something to do with the problem.
I had the same problem with a 796 when it got hot. Never had a scanner not work because it was cold.
The weird part is even when the scanner warmed up it still would not decode the ORION Douglas and Washington sites. It was only those sites that were effected.
It would decode Cass county's P25 channels. Would track both OPPD and Offutt's P25 trucking systems.
 
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realgeo

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It started working fine again. I think the cold temps had something to do with the problem.
I had the same problem with a 796 when it got hot. Never had a scanner not work because it was cold.
The weird part is even when the scanner warmed up it still would not decode the ORION Douglas and Washington sites. It was only those sites that were effected.
It would decode Cass county's P25 channels. Would track both OPPD and Offutt's P25 trucking systems.
This is _VERY_ strange, indeed. However, what you noted does illustrate a difference in the parts of the "ORION" system. The Douglas, Washington, and Pott County Simulcast subsystems are all operated using the LSM Simulcast format. LSM, loosely-put, is implemented in systems running all of the same channels at multiple sites, so as to increase audio quality in the desired coverage area and to further "tune" that coverage area, thus making it difficult to listen to outside of that area.

OPPD, Offutt, any other P25 systems not involved in a simulcast do not employ LSM in this area.

73s
 

SCPD

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The odd part is the scanner would loose the control channel data completely no matter where I was receiving the signal or how strong it was. So I guess something wigged out. It works fine now.
I guess I'll find out later this week if the cold temps is the problem
 

obijohn

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The odd part is the scanner would loose the control channel data completely no matter where I was receiving the signal or how strong it was. So I guess something wigged out. It works fine now.
I guess I'll find out later this week if the cold temps is the problem
I have the same problem. Some days the control channel has a high reliability, and other days
it is "crap". I am sure your problem will periodically return. There is nothing wrong with your '996.

Welcome to "LSM'.

If the scanner manufacturers would use true "IQ" mixers in their receivers (inverse/quadrature) they
would work great for LSM. A technical issue for sure, that adds considerable cost to the receiver.
 

werinshades

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I have the same problem. Some days the control channel has a high reliability, and other days
it is "crap". I am sure your problem will periodically return. There is nothing wrong with your '996.

Welcome to "LSM'.

If the scanner manufacturers would use true "IQ" mixers in their receivers (inverse/quadrature) they
would work great for LSM. A technical issue for sure, that adds considerable cost to the receiver.
Sounds like the same issue we're having on some of the Illinois Starcom sites. I've never heard the term IQ mixers, how would that help us monitoring these systems? As far as cost goes, i'd be willing to give up some of the extras on future scanners to have this included or a "pay as you go option". GPS, Tone-Out , flashing screens to name a few.
 
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I, myself have that problem with my 296d, however if I listen to ORION in the basement, I get better decoding and reception, I have a walk-out basement and have a straight shot, or line of sight to Titan Tower (480/80 split), and the other side of my basement is filled in, and there is a large hill to the west-northwest, pretty much canceling out the site at OFD Station 61.

On the other hand, if I go upstairs, I will get both Titan and a bit OFD Station 61 site, then I run into the LSM issue, however not severe.
 

obijohn

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Your best option as of now for P25 simulcast is a directional antenna.

I took a magnet mount antenna today and attached it to the side of a metal plate several feet in diameter, and oriented it away from the distant sites from my location, and I have been receiving perfectly!

The antenna was horizontally polarized, which should add 20 decibels of attenuation. Yay!

It is ugly, but it works!
 

SCPD

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It seemed to be a problem with the scanner. While on a trip for thanksgiving I had to reinitialize it. It started doing the same thing with Illinois starcom21 system. Then it would lock up on any P25 control channel. It would not do anything when I would push a button. After the restore it has been working flawlessly.
Removed from vehicle as well. It doesn't seem to like cold temps that much.
 
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