TRX-1: Weird Behavior on 700Mhz P25 System.

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ikarus280

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I noticed a while ago that I was no able to hear any 700Mhz of my local P25 Phase I system. I figured at first it was because the main site is Simulcast, and the scanner just didn't get a good enough decode rate to pick up on that site vs. the 150mhz non-simulcast sites.

Then I decided to to create another system with just the simulcast frequency to see how it would handle it.

Now, I still don't get any voice, but the scanner now looks like its picking something up, and the frequencies on the bottom where vc/cc are displayed flash really fast like the unit is picking something up.

From looking at the quickly flashing frequencies, I can see the voice channels are displayed that are't actual frequencies on the system. The cc is 774.531250, and I'll see vc flashing as 796.996250 (among many others, all within 795-799 mhz range), which is not a channel on the site.

Is there an issue with bandplan somewhere? The scanner decodes 150mhz sites on this system with no issue at all.

Here is a link to the system, I am attempting to get site 4-001.

Alaska Land Mobile Radio (ALMR) Trunking System, Statewide, Alaska - Scanner Frequencies
 

troymail

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Simulcast sites are a bear compared to non-simulcast sites. It's possible the well known simulcast issues are the problem.

However, given the radio seems to be tuning to an invalid (?) voice frequency, you may just want to double-check that in the "Site Options" tab for the site is set to "Auto Fill". If the frequency lookup is bad, the radio is being told by the control channel to tune to a (incorrect) voice frequency and the radio, seeing nothing there, immediately returns to the control channel.
 

ikarus280

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Simulcast sites are a bear compared to non-simulcast sites. It's possible the well known simulcast issues are the problem.

However, given the radio seems to be tuning to an invalid (?) voice frequency, you may just want to double-check that in the "Site Options" tab for the site is set to "Auto Fill". If the frequency lookup is bad, the radio is being told by the control channel to tune to a (incorrect) voice frequency and the radio, seeing nothing there, immediately returns to the control channel.

This seems to have corrected the issue. I had to turn the squelch down all the way as well. The settings were not on "Autofill".

Thanks!
 

AggieCon

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The Alaska system uses a unique bandplan, so the default settings will definitely point the radio to dead air. I've had that happen to me as well with some systems in Texas. I am unsure why "Autofill" is not always the default. I can't think of a reason why you would not want a P25 system on autofill.
 

ikarus280

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The Alaska system uses a unique bandplan, .
Yeah. I have trouble with entering some exact 150mhz frequencies our trunked system used. 154.8125 corrects to 154.8150, and 155.5375 corrects to 155.535, for example. My pro-106 accepted these frequencies, but TRX-1 does not.
 

kikito

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Yeah. I have trouble with entering some exact 150mhz frequencies our trunked system used. 154.8125 corrects to 154.8150, and 155.5375 corrects to 155.535, for example. My pro-106 accepted these frequencies, but TRX-1 does not.
Does it do that even with FlexStep Enabled?

I have some sites up here using those same frequencies and the radio accepted them as they are i.e. 154.8125, etc.
 

ikarus280

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Does it do that even with FlexStep Enabled?



I have some sites up here using those same frequencies and the radio accepted them as they are i.e. 154.8125, etc.


I'll double check tonight. I thought I had, but then again I also thought I had my 700mhz sites all set up right.

I should note that right now it accepts entries of 154.66250 and 155.91250 without changing them to 665 or 915.
 
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