Chicago O'Hare UHF T-Band TRS Help

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Lynch_Christopher

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I am in Chicago for the next two weeks and I am interested in running Unitrunker on the Chicago O'Hare UHF T-Band digital system. I have been having trouble getting the system to run properly. Multiple system site windows keep popping up and I have no way of closing them so as a result I have to shut down Unitrunker. Not sure if it is a issue with the receiver settings. I was also wondering do I need to set a band plan or should Unitrunker do that automatically. Attached is a screenshot of the receiver setup is there anything that I need to change?

Thanks,
 

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Lynch_Christopher

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The baud rate should be 115200, not 9600. Set the program and the radio to match.
Okay I set the radio and the reciever at 115200. The run state is still in stopped. For some reason after I changed the baud rate to 115200 and clicked start the program just quits and I have to reopen it.
 

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SCPD

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A possible workaround is to save changes to your receiver first (in a stopped state) and then quit Unitrunker (so it saves the data) and re-launch. Then click the Run button for your receiver.
 

Lynch_Christopher

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Crud.

Please send a crash dump.

Crash Dumps
I uninstalled untitrunker and installed I again and that seemed to solve the issue. However I am not getting any of th frequencies showing up on the channels. If I recall shouldn't they appear automatically? Also under call history there is 533(LCN) 0.0000 for the frequency and then under audience it says "frequency needed!" I also have a band plan set to the following:

Base 476.5000
Lower base: 476.5000
Upper base: 481.2375
Offset 380
Spacing 12.5

In addition unitrunker seems be picking up the talkgroups coming through but I am
not getting any voice out of the scanner.
 
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SCPD

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I also have a band plan set to the following:

Base 476.5000
Lower base: 476.5000
Upper base: 481.2375
Offset 380
Spacing 12.5
Try ...
LCN Low 380
LCN Hi 759
Base frequency 476.5 MHz
Spacing 12.5 kHz

There's an Apply button on the toolbar.

In addition unitrunker seems be picking up the talkgroups coming through but I am
not getting any voice out of the scanner.
The signal receiver stays on the control channel. You can configure an additional receiver for voice following.
 

Lynch_Christopher

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Try ...
LCN Low 380
LCN Hi 759
Base frequency 476.5 MHz
Spacing 12.5 kHz

There's an Apply button on the toolbar.

The signal receiver stays on the control channel. You can configure an additional receiver for voice following.
Thanks I'll give that a try. After I change the bandplan should I restart unitrunker or the scanner to have the settings take affect?
 

Lynch_Christopher

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Okay it looks like it has started to recognize one frequency but LCN 555 frequency 0.0000 " frequency needed!" is still red. Should I also input the new band plan you gave me into the scanner as well?
 

SCPD

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The XT models all do this. I've reported the problem to Uniden America (almost 3 years ago). For reliable decoding from your BCD396XT, you'll need a discriminator tap.

The problem - which applies only to Motorola systems - is simple. The XT models pass bad data with good. There is no way to to tell them apart. The GRE models mark bad frames as such. The HP1E provides the actual waveform so decoding Motorola from this model is not a problem.

Improving reception will reduce the problem but won't make it go completely away.

If you don't want to tap your radio, take a look at Trunk88. It's supposed to decode Motorola from headphone audio.
 
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Lynch_Christopher

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May 28, 2006
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Bethpage, NY
The XT models all do this. I've reported the problem to Uniden America (almost 3 years ago). For reliable decoding from your BCD396XT, you'll need a discriminator tap.

The problem - which applies only to Motorola systems - is simple. The XT models pass bad data with good. There is no way to to tell them apart. The GRE models mark bad frames as such. The HP1E provides the actual waveform so decoding Motorola from this model is not a problem.

Improving reception will reduce the problem but won't make it go completely away.

If you don't want to tap your radio, take a look at Trunk88. It's supposed to decode Motorola from headphone audio.
Thanks for the info I appreciate it. This has been the first time that I have run into this problem with the multiple systems showing up. When I monitor the Nashua, NH TRS I haven't had any issues with multiple systems showing up or the control channel not being recognized. I wonder if it is something to do with the Chicago O'Hare TRS.
 

radioman2001

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I have had the same issues with NYC-DOITT and Westchester Fire. Apparently with simulcast systems I've noticed that when the system fades in and out that Unitrunker falses and gives bad info, like multiple wrong system ID's windows and even talk group numbers. When I receive a strong signal, I have no problems.
 
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