IL-Will County p25 help

[mrc333777]

I have the RTL-SDR v3 dongle and trying to sort out which freq to use for p25 for Will County.. Any suggestions on the right freq, bandwidth and proper gains? I'm using the long antennas in the kit right now. I'm close to the Frankfort/Mokena area. Thanks much!

 

[BTJustice]

https://www.radioreference.com/apps/db/?siteId=10090

 

[slicerwizard]

"Site Modulation: C4FM Phase 2"

Who made up that nonexistent mode?

 

[simpilo]

I have the RTL-SDR v3 dongle and trying to sort out which freq to use for p25 for Will County.. Any suggestions on the right freq, bandwidth and proper gains? I'm using the long antennas in the kit right now. I'm close to the Frankfort/Mokena area. Thanks much!

Here is the corrrect RRDB Site
https://www.radioreference.com/apps/db/?sid=9608

I hope you have DSDPlus Fastlane for it.

You want "Central Patrol" which covers

• Frankfort PD
• Manhattan PD
• Mokena PD
• New Lenox PD
• Sheriff Homer Glen

 

[BTJustice]

The one I posted is Will Co. simulcast so you "SHOULD" have both local and state agencies you can monitor. Try and see. Lockout groups you don't want to hear.

 

[jl2s]

A few weeks ago I I asked about the Will County site and using DSD+ Fastlane on the Illinois part of the forum. I never got a response.
I can never get DSD+ to populate the channel activity windows when tuning to the control channel for the Will County site.

The event log window populates, shows radios regstering or being denied access etc..., the DSD window scrolls with good data, but the channel activity window never populates. Any ideas?
I'll add, that I can successfully listen to the site using a handheld scanner and also using SDRtrunk, but it won't work in DSD+

However, if I manually park DSD+ on a voice channel it will decode it and I can hear talk, but when parking the DSD+ on the control channel then the channel activity window for DSD+ never ever populates.

Any ideas why DSD+ wont fill up the channel activity window? Only happens on this Will County site for me.

Here's a screenshot of my DSD+ showing the channel activity window never filling up.

 

[slicerwizard]

It looks like DSD+ isn't decoding the bandplan. I'd be sending some raw CC audio to the developers...

 

[DRL-XM43]

Have you noticed a red text message fly by in the event window saying you need to supply a bandwidth in your batch file?

 

[mrc333777]

The one I posted is Will Co. simulcast so you "SHOULD" have both local and state agencies you can monitor. Try and see. Lockout groups you don't want to hear.

Great, thank you @slicerwizard, the STARCOM21 i can easily tune into and monitor with no problems it appears. Believe it sorts out the right bandwidth settings. I hear chatter from the larger Chicago-land area.

Put the P25 posting with the 854.3375c freq and others doesn't seem to work well for me and was wondering if it was my antenna setup. More interested in the local chatter if a future version of DSD+ can decode it.. Thanks!

 

[jl2s]

Have you noticed a red text message fly by in the event window saying you need to supply a bandwidth in your batch file?

Are you referring to this?
FM demodulated PSK signal detected
Use TCP linked FMPA/FMPP/FMP24 and correct channel bandwidth to decode

 

[jl2s]

It looks like DSD+ isn't decoding the bandplan. I'd be sending some raw CC audio to the developers...

Where do I send it?
What would you recommend for length of time I record the Control Channel?

 

[slicerwizard]

Are you referring to this?
FM demodulated PSK signal detected
Use TCP linked FMPA/FMPP/FMP24 and correct channel bandwidth to decode

You were using the wrong bandwidth, but 1R mode selects appropriate values as it retunes to voice and back to control, so no major worries there.

Where do I send it?
What would you recommend for length of time I record the Control Channel?

I send stuff to the "From:" address that's in the notification emails. I would suspect that 30 seconds or so during some voice calls would be all they'd need. Press R in DSD+ to start/stop recording.

 

[simpilo]

Based on observing local P25 systems here, 1R will tune 9.5khz BW for control frequency and tune 12.5khz bandwidth for voice frequency. Ensure 9.5khz and you have a nice and high signal peak. Some say signal strength don't much matter to a point but I am trying to help you ensure you are receiving a good signal.

It won't hurt to tell FMP24 -b-12.5 switch for added insurance. This sets 12.5khz to be the bandwidth across all frequencies.

Also check your .bat files to be sure both have the same port number.

Everyone seems to have forgot this one. I have forgotten which file it is. If this file is deleted then P25 will start to work. This has been mentioned a while back here on the forums by another user. I can't remember the thread. If we can figure out which file it is then whoever can tell you which DSDPlus.???? Just delete it and restart DSD FL. DSDPlus FL will create a fresh new one.

After thought
..... I think its DSDPlus.bin

 

[DRL-XM43]

Are you referring to this?
FM demodulated PSK signal detected
Use TCP linked FMPA/FMPP/FMP24 and correct channel bandwidth to decode

Yes and in my case it will not decode unless I include the "correct" BW instruction in the start up batch file, like -b-9.5 any other value brings up the message again (P25 system) but not all of them?.

This only started in the latest FS release, before DSD+ told FMP24 what the BW should be?

 

[simpilo]

Yes and in my case it will not decode unless I include the "correct" BW instruction in the start up batch file, like -b-9.5 any other value brings up the message again (P25 system) but not all of them?.

This only started in the latest FS release, before DSD+ told FMP24 what the BW should be?

I think I see the issue. 9.5khz is fine for CC but not for voice. set it for -b-12.5

 

[slicerwizard]

9.5 kHz is fine for P25 Phase I voice. The carriers aren't 12.5 kHz wide.

 

[jl2s]

I think I see the issue. 9.5khz is fine for CC but not for voice. set it for -b-12.5

Tried it, no change.

 

[slicerwizard]

Because your issue has nothing to do with bandwidth settings.

 

[simpilo]

Tried it, no change.

Something is haywire. try deleting dsdplus.bin and load dsdplus it will write a new one. Basically it's a 'reset'. that bin file saves windows sizes, window positions, and other user settings. whatever is present in the batch files over rides the bin file. Maybe a old setting that gets in the way. wouldn't hurt to try it.

 

[slicerwizard]

Deleting files that don't need to be deleted won't make the program suddenly start decoding the IDEN_UP_TDMA messages.