RWC Simulcast C: Chandler Base Frequency?

AZK602

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Wondering if anyone might have or is willing to share what the Base Frequency for the Maricopa RWC is? Working on a non-affiliated scan on an XTS 5000 III and the radio does pick up traffic on the channels, I can see the radio display is switching to those trunk channels I have programmed on CH 17-25 in my scanlist. However I do not get any audio. Suspect it may be the base frequency is incorrect in my config. The base frequency of 762.00625 with a channel spacing of 12.5kHz seems to be the one that will pick up traffic on the talkgroup but just don't hear the actual audio.

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I hope to get a SDR up and running eventually so I can find this info on my own but thought I'd ask for a hand from you all until then.

I'm well aware of the care that must be taken when using a XTS as a scanner.

Thanks
 

AZK602

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Yep, I've got all of those in my Control Channels list.

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Based on the video and research I have been doing it seems that I need to determine that base frequency for this to work.

This was a pretty good video on how this can be accomplished,
. The video mentions that you need to find the base frequency most commonly done with a SDR. The video is for a APX but the CPS settings for a XTS are very similar.
 

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chrismol1

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Try using the first channel identifier, ASTRO25 Control Channels and switch the Channel ID Number to 1 instead of 3, the 6.25 channel spacing with 762
 

chrismol1

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Did it work? Is it possible the talkgroup is P25 Phase 2 TDMA? Early version of XTS firmware will show the talkgroup as instructed from control channel but of course it cannot receive as the XTS/XTL is Phase 1 FDMA only
 

AZK602

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Thanks @chrismol1 for the response, gave it a try with Channel ID 1 (762.00625 with 6.25 spacing) but no luck, still no audio. I was wondering if this might be related to FDMA\TDMA. I was hopeful it would work as I have seen the Phoenix City Park rangers still using XTS5000's, maybe their is support for Phase I, but a XTS\FDMA radio has to associate with that talk group and force it down to FDMA, something probably not happening on most talk groups.

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AZK602

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I did get some success, part of my issue was a talk group was assigned to the conventional personality used in the zone channel assignments for channels 1 -16. Once that was removed I was able to hear transmissions for the Park Rangers, some traffic on K9 and 7 for PHX fire. However I was not able to hear traffic on other K channels. This I believe is because a radio on those channels was a FDMA radio and the channel defaulted to FMDA instead of TDMA. Either way great learning.

Here is the base freq I used.

762.00625MHz Channel Spacing 6.250 & Transmit Offset 45.000MHZ Transmit Offset Sign +

Thanks for the help
 

KevinC

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I did get some success, part of my issue was a talk group was assigned to the conventional personality used in the zone channel assignments for channels 1 -16. Once that was removed I was able to hear transmissions for the Park Rangers, some traffic on K9 and 7 for PHX fire. However I was not able to hear traffic on other K channels. This I believe is because a radio on those channels was a FDMA radio and the channel defaulted to FMDA instead of TDMA. Either way great learning.

Here is the base freq I used.

762.00625MHz Channel Spacing 6.250 & Transmit Offset 45.000MHZ Transmit Offset Sign +

Thanks for the help
Anything 700 should have a plus 30 mHz offset.
 

AZK602

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@KevinC I changed the offset to 30.000 MHz and stopped hearing traffic, changed it back to 45.000 MHz and started hearing traffic again. Any thoughts why that might make a difference? The transmit offset shouldn't matter right, since I am only listening?
 

KevinC

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@KevinC I changed the offset to 30.000 MHz and stopped hearing traffic, changed it back to 45.000 MHz and started hearing traffic again. Any thoughts why that might make a difference? The transmit offset shouldn't matter right, since I am only listening?
No idea. Like I posted though, your radio needs to match what the system is broadcasting. If this is a Motorola system they usually use a more or less standard band plan on almost all systems. Search the Motorola forum as I think people have posted it there.
 

chrismol1

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Is the coverage type set to SmartZone? You say you hear things then not, is it roaming to another site than the talkgroups you're expecting to hear aren't on that tower at the moment then a user roams and then you're hearing them again, or your radio is in an overlap area and its switching sites
 

Foresigt

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Your programming software appears to be for the XTS series.. Many of the agencies on RWC have moved to TDMA (Phase II) and and XTS will not do Phase II. That is probably the root of your problem.
 

mbnv992

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Yep as was stated, RWC is phase 2. You’re using the wrong radio. Time to upgrade to an apx6000. Or better yet, an SDS100.
 

KB7MIB

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The RWC has a mix of Phase I and Phase II talkgroups, with the vast majority still being Phase I. The known Phase II TG's are shown in the RRDB with a "T" under the mode column.

Chandler PD has a mix of both, with Patrol A/B/C being Phase II in the clear. However, their other TG's are also mostly encrypted, regardless of Phase I or II. A-06 Metro, A-10 Bike, E-11 Explorer, and J-16 Jail are Phase I in the clear.

Maricopa PD's 4 known TG's are all Phase II, with 3 of them being encrypted

All of Phoenix FD RDC K-deck is Phase I. However, you likely will not hear K-6 or K-9 on Simulcast C, because those TG's serve the Northwest and Southwest Valley cities, respectively, and simply aren't carried on Simulcast C, unless someone from one of those departments/districts happens to be in Sim C's coverage area, and wants to monitor an incident that is ongoing on the Westside on either K-6 or K-9.
K-10/11/12 (mountain rescues and major medical incidents) may or may not be heard on Sim C. I think I recall it being mentioned here that they do have some geographic assignments, but I don't recall the exact breakdown.

Phoenix PD A-deck precinct TG's are all Phase II, but A-4 South Mountain is probably the only one that would be heard on Sim C. (I may be wrong about that, however.)

I don't know if Tempe PD would ever roam onto Sim C. They too have a mix of Phase I and Phase II TG's, and a mix of encryption, with their A-04 South patrol TG being Phase II in the clear.

I hope this helps.

John
Peoria
 
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