Harris P25 demodulation

[Jeff Thompson]

Actually, this topic could probably be widened a bit and be more general, as I'm seeing some odd behavior here and there on select systems. 

Overall, if a system is straight C4FM (non-simulcast, trunked or conventional), things seem fine for the most part. Some exceptions exist but I'm trying to chase down whether that's on the RF side or on the SDR side. 

If listening to a Motorola LSM system, and selecting LSM in SDRT, really nice performance in general. 

But... things break down a bit around the edges. 

For example (logs below), when I was passing through a Harris VHF P25 trunked system recently, I originally set it for LSM. I knew it was a simulcast system, and I knew it was Harris, and I know Harris has CQPSK/LSM, although they call it other things. 

But I got no decode at all when I got into the coverage area. 

Huh. I can see the spikes in the waterfall, they look great, but nothing. 

Out of "why not" I set it to C4FM and got decode right away. 

Huh. 

So Harris has "WCQPSK" (9K70D1W) and "HDQPSK" (9K80D7W) for simulcast modes. They also have other modes, but  the FCC emission for this license is 11K3F1D - which is a 11.3 KHz wide modulation. A mistake in the FCC filing? Perhaps. 

But I wouldn't think that either of these would be so different from Motorola's LSM to be that much of a problem. 

In any case, matching up the emissions to the actual modulation is a bit harder than one might hope. For example, both regular C4FM, Motorola ASTRO Widepulse and Harris "LSM" all share the F1D suffix, even though they are all fairly different from each other. Google isn't being all that helpful either. 

Didn't have a scope with me, so I have no idea of what the waveform actually looks like on this system. While I find it a bit hard to believe that C4FM would be used on the base side when LSM is available, I suppose it's possible. I looked at other Harris systems, and those systems have a more reasonable 9K70F1D emissions designator (9.7 Khz bandwidth, but apparently this is LSM?). 

In any case, when using C4FM, lots of output in the logs that might indicate something is still amiss. Redacted log for a few seconds is below. 

Normally, I'll see the TAIL/STUFF BITS message now and again on Motorola LSM systems. But to see it every second, third or fourth message seems a tad excessive.

To be clear - the setup seemed to be working OK. Not great, but it would be hard to pin the reason for that down. 

20201127 163841,PASSED,NAC:000 TSBK1 GRP_VCH_GRNT_UPX TALKGROUP:57516 CHAN:0-1685/0-3284 PRI4 CIRCUIT

20201127 163841,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163841,PASSED,NAC:000 TSBK1 SYS_SVC_BCAST    AVAILABLE SERVICES [GROUP_VOICE, INDIVIDUAL_VOICE, INDIVIDUAL_DATA, UNIT_REGISTRATION, GROUP_AFFILIATION, AUTHENTICATION, USER_STATUS, USER_MESSAGE, UNIT_STATUS, USER_STATUS_QUERY, UNIT_STATUS_QUERY, UNIT_PAGE, EMERGENCY_ALARM] SUPPORTED SERVICES [GROUP_VOICE, INDIVIDUAL_VOICE, INDIVIDUAL_DATA, UNIT_REGISTRATION, GROUP_AFFILIATION, AUTHENTICATION, USER_STATUS, USER_MESSAGE, UNIT_STATUS, USER_STATUS_QUERY, UNIT_STATUS_QUERY, UNIT_PAGE, EMERGENCY_ALARM]

20201127 163841,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163841,PASSED,NAC:000 TSBK1 GRP_VCH_GRNT_UPX TALKGROUP:57516 CHAN:0-1685/0-3284 PRI4 CIRCUIT

20201127 163841,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163841,PASSED,NAC:000 TSBK1 ADJ SITE STATUS  SYSTEM:000 RFSS:14 SITE:14 CHANNEL:1-285 LRA:14 FLAGS [VALID INFORMATION, ACTIVE RFSS CONNECTION] SERVICES [DATA, VOICE, REGISTRATION]

20201127 163841,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163841,PASSED,NAC:000 TSBK1 GRP_VCH_GRNT_UPX TALKGROUP:57516 CHAN:0-1685/0-3284 PRI4 CIRCUIT

20201127 163841,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163841,PASSED,NAC:000 TSBK1 SCCB_CCH_BCST_EX RFSS:1 SITE:1 CHAN:0-1904/0-1 SERVICE OPTIONS:[BACKUP CONTROL CHANNEL]

20201127 163841,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163841,PASSED,NAC:000 TSBK1 GRP_VCH_GRNT_UPX TALKGROUP:57516 CHAN:0-1685/0-3284 PRI4 CIRCUIT

20201127 163841,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163841,PASSED,NAC:000 AMBTC RFSS_STATUS_BCST SYSTEM:000 SITE:1 ACTIVE NETWORK CONNECTION RFSS:1 LRA:1 CHAN:0-1676/0-1264

20201127 163841,PASSED,NAC:000 TSBK1 GRP_VCH_GRNT_UPX TALKGROUP:57516 CHAN:0-1685/0-3284 PRI4 CIRCUIT

20201127 163841,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163841,PASSED,NAC:000 AMBTC NET_STATUS_BCAST WACN:599849 SYSTEM:000 CHAN:0-1676/0-1264 SERVICES:[DATA, VOICE, REGISTRATION]

20201127 163841,PASSED,NAC:000 TSBK1 GRP_VCH_GRNT_UPX TALKGROUP:57516 CHAN:0-1685/0-3284 PRI4 CIRCUIT

20201127 163841,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163841,PASSED,NAC:000 TSBK1 IDEN_UPDATE_VUHF ID:0 OFFSET:0 SPACING:2500 BASE:150775000 FDMA BW:12500

20201127 163841,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163841,PASSED,NAC:000 TSBK1 GRP_VCH_GRNT_UPX TALKGROUP:57516 CHAN:0-1685/0-3284 PRI4 CIRCUIT

20201127 163841,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163841,PASSED,NAC:000 TSBK1 SYS_SVC_BCAST    AVAILABLE SERVICES [GROUP_VOICE, INDIVIDUAL_VOICE, INDIVIDUAL_DATA, UNIT_REGISTRATION, GROUP_AFFILIATION, AUTHENTICATION, USER_STATUS, USER_MESSAGE, UNIT_STATUS, USER_STATUS_QUERY, UNIT_STATUS_QUERY, UNIT_PAGE, EMERGENCY_ALARM] SUPPORTED SERVICES [GROUP_VOICE, INDIVIDUAL_VOICE, INDIVIDUAL_DATA, UNIT_REGISTRATION, GROUP_AFFILIATION, AUTHENTICATION, USER_STATUS, USER_MESSAGE, UNIT_STATUS, USER_STATUS_QUERY, UNIT_STATUS_QUERY, UNIT_PAGE, EMERGENCY_ALARM]

20201127 163841,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163841,PASSED,NAC:000 TSBK1 GRP_VCH_GRNT_UPX TALKGROUP:57516 CHAN:0-1685/0-3284 PRI4 CIRCUIT

20201127 163841,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163841,PASSED,NAC:000 TSBK1 ADJ SITE STATUS  SYSTEM:000 RFSS:14 SITE:14 CHANNEL:1-285 LRA:14 FLAGS [VALID INFORMATION, ACTIVE RFSS CONNECTION] SERVICES [DATA, VOICE, REGISTRATION]

20201127 163841,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163841,PASSED,NAC:000 TSBK1 GRP_VCH_GRNT_UPX TALKGROUP:57516 CHAN:0-1685/0-3284 PRI4 CIRCUIT

20201127 163841,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163841,PASSED,NAC:000 TSBK1 SCCB_CCH_BCST_EX RFSS:1 SITE:1 CHAN:0-1685/0-1 SERVICE OPTIONS:[BACKUP CONTROL CHANNEL]

20201127 163841,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163841,PASSED,NAC:000 TSBK1 GRP_VCH_GRNT_UPX TALKGROUP:57516 CHAN:0-1685/0-3284 PRI4 CIRCUIT

20201127 163841,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163841,PASSED,NAC:000 AMBTC RFSS_STATUS_BCST SYSTEM:000 SITE:1 ACTIVE NETWORK CONNECTION RFSS:1 LRA:1 CHAN:0-1676/0-1264

20201127 163842,PASSED,NAC:000 TSBK1 GRP_VCH_GRNT_UPX TALKGROUP:57516 CHAN:0-1685/0-3284 PRI4 CIRCUIT

20201127 163842,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163842,PASSED,NAC:000 AMBTC NET_STATUS_BCAST WACN:599849 SYSTEM:000 CHAN:0-1676/0-1264 SERVICES:[DATA, VOICE, REGISTRATION]

20201127 163842,PASSED,NAC:000 TSBK1 GRP_VCH_GRNT_UPX TALKGROUP:57516 CHAN:0-1685/0-3284 PRI4 CIRCUIT

20201127 163842,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163842,PASSED,NAC:000 TSBK1 IDEN_UPDATE      ID:1 OFFSET:30000000 SPACING:6250 BASE:770000000 FDMA BW:12500

20201127 163842,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163842,PASSED,NAC:000 TSBK1 GRP_VCH_GRNT_UPX TALKGROUP:57516 CHAN:0-1685/0-3284 PRI4 CIRCUIT

20201127 163842,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163842,PASSED,NAC:000 TSBK1 SYS_SVC_BCAST    AVAILABLE SERVICES [GROUP_VOICE, INDIVIDUAL_VOICE, INDIVIDUAL_DATA, UNIT_REGISTRATION, GROUP_AFFILIATION, AUTHENTICATION, USER_STATUS, USER_MESSAGE, UNIT_STATUS, USER_STATUS_QUERY, UNIT_STATUS_QUERY, UNIT_PAGE, EMERGENCY_ALARM] SUPPORTED SERVICES [GROUP_VOICE, INDIVIDUAL_VOICE, INDIVIDUAL_DATA, UNIT_REGISTRATION, GROUP_AFFILIATION, AUTHENTICATION, USER_STATUS, USER_MESSAGE, UNIT_STATUS, USER_STATUS_QUERY, UNIT_STATUS_QUERY, UNIT_PAGE, EMERGENCY_ALARM]

20201127 163842,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163842,PASSED,NAC:000 TSBK1 GRP_VCH_GRNT_UPX TALKGROUP:57516 CHAN:0-1685/0-3284 PRI4 CIRCUIT

20201127 163842,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163842,PASSED,NAC:000 TSBK1 ADJ SITE STATUS  SYSTEM:000 RFSS:14 SITE:14 CHANNEL:1-285 LRA:14 FLAGS [VALID INFORMATION, ACTIVE RFSS CONNECTION] SERVICES [DATA, VOICE, REGISTRATION]

20201127 163842,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163842,PASSED,NAC:000 TSBK1 GRP_VCH_GRNT_UPX TALKGROUP:57516 CHAN:0-1685/0-3284 PRI4 CIRCUIT

20201127 163842,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163842,PASSED,NAC:000 TSBK1 SCCB_CCH_BCST_EX RFSS:1 SITE:1 CHAN:0-1790/0-1 SERVICE OPTIONS:[BACKUP CONTROL CHANNEL]

20201127 163842,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163842,PASSED,NAC:000 TSBK1 GRP_VCH_GRNT_UPX TALKGROUP:57516 CHAN:0-1685/0-3284 PRI4 CIRCUIT

20201127 163842,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163842,PASSED,NAC:000 AMBTC RFSS_STATUS_BCST SYSTEM:000 SITE:1 ACTIVE NETWORK CONNECTION RFSS:1 LRA:1 CHAN:0-1676/0-1264

20201127 163842,PASSED,NAC:000 AMBTC NET_STATUS_BCAST WACN:599849 SYSTEM:000 CHAN:0-1676/0-1264 SERVICES:[DATA, VOICE, REGISTRATION]

20201127 163842,PASSED,NAC:000 TSBK1 IDEN_UPDATE_VUHF ID:0 OFFSET:0 SPACING:2500 BASE:150775000 FDMA BW:12500

20201127 163842,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163842,PASSED,NAC:000 TSBK1 SYS_SVC_BCAST    AVAILABLE SERVICES [GROUP_VOICE, INDIVIDUAL_VOICE, INDIVIDUAL_DATA, UNIT_REGISTRATION, GROUP_AFFILIATION, AUTHENTICATION, USER_STATUS, USER_MESSAGE, UNIT_STATUS, USER_STATUS_QUERY, UNIT_STATUS_QUERY, UNIT_PAGE, EMERGENCY_ALARM] SUPPORTED SERVICES [GROUP_VOICE, INDIVIDUAL_VOICE, INDIVIDUAL_DATA, UNIT_REGISTRATION, GROUP_AFFILIATION, AUTHENTICATION, USER_STATUS, USER_MESSAGE, UNIT_STATUS, USER_STATUS_QUERY, UNIT_STATUS_QUERY, UNIT_PAGE, EMERGENCY_ALARM]

20201127 163842,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163842,PASSED,NAC:000 TSBK1 ADJ SITE STATUS  SYSTEM:000 RFSS:14 SITE:14 CHANNEL:1-285 LRA:14 FLAGS [VALID INFORMATION, ACTIVE RFSS CONNECTION] SERVICES [DATA, VOICE, REGISTRATION]

20201127 163842,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163842,PASSED,NAC:000 TSBK1 SCCB_CCH_BCST_EX RFSS:1 SITE:1 CHAN:0-1904/0-1 SERVICE OPTIONS:[BACKUP CONTROL CHANNEL]

20201127 163842,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163842,PASSED,NAC:000 AMBTC RFSS_STATUS_BCST SYSTEM:000 SITE:1 ACTIVE NETWORK CONNECTION RFSS:1 LRA:1 CHAN:0-1676/0-1264

20201127 163842,PASSED,NAC:000 AMBTC NET_STATUS_BCAST WACN:599849 SYSTEM:000 CHAN:0-1676/0-1264 SERVICES:[DATA, VOICE, REGISTRATION]

20201127 163842,PASSED,NAC:000 TSBK1 IDEN_UPDATE      ID:1 OFFSET:30000000 SPACING:6250 BASE:770000000 FDMA BW:12500

20201127 163842,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163842,PASSED,NAC:000 TSBK1 SYS_SVC_BCAST    AVAILABLE SERVICES [GROUP_VOICE, INDIVIDUAL_VOICE, INDIVIDUAL_DATA, UNIT_REGISTRATION, GROUP_AFFILIATION, AUTHENTICATION, USER_STATUS, USER_MESSAGE, UNIT_STATUS, USER_STATUS_QUERY, UNIT_STATUS_QUERY, UNIT_PAGE, EMERGENCY_ALARM] SUPPORTED SERVICES [GROUP_VOICE, INDIVIDUAL_VOICE, INDIVIDUAL_DATA, UNIT_REGISTRATION, GROUP_AFFILIATION, AUTHENTICATION, USER_STATUS, USER_MESSAGE, UNIT_STATUS, USER_STATUS_QUERY, UNIT_STATUS_QUERY, UNIT_PAGE, EMERGENCY_ALARM]

20201127 163842,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163842,PASSED,NAC:000 TSBK1 ADJ SITE STATUS  SYSTEM:000 RFSS:14 SITE:14 CHANNEL:1-285 LRA:14 FLAGS [VALID INFORMATION, ACTIVE RFSS CONNECTION] SERVICES [DATA, VOICE, REGISTRATION]

20201127 163842,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163842,PASSED,NAC:000 TSBK1 SCCB_CCH_BCST_EX RFSS:1 SITE:1 CHAN:0-1685/0-1 SERVICE OPTIONS:[BACKUP CONTROL CHANNEL]

20201127 163842,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163843,PASSED,NAC:000 AMBTC RFSS_STATUS_BCST SYSTEM:000 SITE:1 ACTIVE NETWORK CONNECTION RFSS:1 LRA:1 CHAN:0-1676/0-1264

20201127 163843,PASSED,NAC:000 AMBTC NET_STATUS_BCAST WACN:599849 SYSTEM:000 CHAN:0-1676/0-1264 SERVICES:[DATA, VOICE, REGISTRATION]

20201127 163843,PASSED,NAC:000 TSBK1 IDEN_UPDATE_VUHF ID:0 OFFSET:0 SPACING:2500 BASE:150775000 FDMA BW:12500

20201127 163843,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163843,PASSED,NAC:000 TSBK1 SYS_SVC_BCAST    AVAILABLE SERVICES [GROUP_VOICE, INDIVIDUAL_VOICE, INDIVIDUAL_DATA, UNIT_REGISTRATION, GROUP_AFFILIATION, AUTHENTICATION, USER_STATUS, USER_MESSAGE, UNIT_STATUS, USER_STATUS_QUERY, UNIT_STATUS_QUERY, UNIT_PAGE, EMERGENCY_ALARM] SUPPORTED SERVICES [GROUP_VOICE, INDIVIDUAL_VOICE, INDIVIDUAL_DATA, UNIT_REGISTRATION, GROUP_AFFILIATION, AUTHENTICATION, USER_STATUS, USER_MESSAGE, UNIT_STATUS, USER_STATUS_QUERY, UNIT_STATUS_QUERY, UNIT_PAGE, EMERGENCY_ALARM]

20201127 163843,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163843,PASSED,NAC:000 TSBK1 ADJ SITE STATUS  SYSTEM:000 RFSS:14 SITE:14 CHANNEL:1-285 LRA:14 FLAGS [VALID INFORMATION, ACTIVE RFSS CONNECTION] SERVICES [DATA, VOICE, REGISTRATION]

20201127 163843,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163843,PASSED,NAC:000 TSBK1 SCCB_CCH_BCST_EX RFSS:1 SITE:1 CHAN:0-1790/0-1 SERVICE OPTIONS:[BACKUP CONTROL CHANNEL]

20201127 163843,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163843,PASSED,NAC:000 AMBTC RFSS_STATUS_BCST SYSTEM:000 SITE:1 ACTIVE NETWORK CONNECTION RFSS:1 LRA:1 CHAN:0-1676/0-1264

20201127 163843,PASSED,NAC:000 AMBTC NET_STATUS_BCAST WACN:599849 SYSTEM:000 CHAN:0-1676/0-1264 SERVICES:[DATA, VOICE, REGISTRATION]

20201127 163843,PASSED,NAC:000 TSBK1 IDEN_UPDATE      ID:1 OFFSET:30000000 SPACING:6250 BASE:770000000 FDMA BW:12500

20201127 163843,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163843,PASSED,NAC:000 TSBK1 SYS_SVC_BCAST    AVAILABLE SERVICES [GROUP_VOICE, INDIVIDUAL_VOICE, INDIVIDUAL_DATA, UNIT_REGISTRATION, GROUP_AFFILIATION, AUTHENTICATION, USER_STATUS, USER_MESSAGE, UNIT_STATUS, USER_STATUS_QUERY, UNIT_STATUS_QUERY, UNIT_PAGE, EMERGENCY_ALARM] SUPPORTED SERVICES [GROUP_VOICE, INDIVIDUAL_VOICE, INDIVIDUAL_DATA, UNIT_REGISTRATION, GROUP_AFFILIATION, AUTHENTICATION, USER_STATUS, USER_MESSAGE, UNIT_STATUS, USER_STATUS_QUERY, UNIT_STATUS_QUERY, UNIT_PAGE, EMERGENCY_ALARM]

20201127 163843,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

20201127 163843,PASSED,NAC:000 TSBK1 ADJ SITE STATUS  SYSTEM:000 RFSS:14 SITE:14 CHANNEL:1-285 LRA:14 FLAGS [VALID INFORMATION, ACTIVE RFSS CONNECTION] SERVICES [DATA, VOICE, REGISTRATION]

20201127 163843,PASSED,<-> TAIL/STUFF BITS PROCESSED [42]

[Terry Van Sickle]

Well, I can't offer much from the inner working perspective, but I can offer another viewpoint... of the 3 systems I mentioned previously, all 3 are absolutely known to be simulcast. 1 is Harris (3-site), 2 are Moto (both 2-site). All 3 are pure 700. All 3 don't decode worth a crap when set to LSM... but decode great (with the aforementioned sync loss when the tuner hops around) when set to C4FM. I found that odd as well.

[Chance Lindsey]

Terry, I recognize you from the DFW area. I feed Sachse to Broadcastify from SDR Trunk from the GRMS simulcast system from a dedicated PC with an Airspy. On my regular workstation I listen to the rest of what's unencrypted on GMRS and also to PAWM.  All setup as LSM. A mix of an AirSpy and RTL dongles. No issues. If those aren't one or two of the three you mentioned, what are you listening to? I am happy to give it a shot. I work in Irving a few days a week and can try there as well.  --Chance

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[wemana...@gmail.com]

On Sunday, November 29, 2020 at 3:36:24 PM UTC-5 Jeff Thompson wrote:

Actually, this topic could probably be widened a bit and be more general, as I'm seeing some odd behavior here and there on select systems. 

Overall, if a system is straight C4FM (non-simulcast, trunked or conventional), things seem fine for the most part. Some exceptions exist but I'm trying to chase down whether that's on the RF side or on the SDR side. 

If listening to a Motorola LSM system, and selecting LSM in SDRT, really nice performance in general. 

But... things break down a bit around the edges. 

For example (logs below), when I was passing through a Harris VHF P25 trunked system recently, I originally set it for LSM. I knew it was a simulcast system, and I knew it was Harris, and I know Harris has CQPSK/LSM, although they call it other things. 

Harris "LSM" is slightly tweaked WCQPSK and HDQPSK as you list later. "tweaked"

 

But I got no decode at all when I got into the coverage area. 

Huh. I can see the spikes in the waterfall, they look great, but nothing. 

Out of "why not" I set it to C4FM and got decode right away. 

Huh. 

So Harris has "WCQPSK" (9K70D1W) and "HDQPSK" (9K80D7W) for simulcast modes. They also have other modes, but  the FCC emission for this license is 11K3F1D - which is a 11.3 KHz wide modulation. A mistake in the FCC filing? Perhaps.

These are Harris's "tweeks" to CQPSK aka LSM mainly for marketing and some technical. I am noting going to get into which is which here, not the place. In general these 3 should be "compatible" else you don't meet the P25 approval tests. Again "should." Now "should' and real world don't always meet. :)

 

Normally, I'll see the TAIL/STUFF BITS message now and again on Motorola LSM systems. But to see it every second, third or fourth message seems a tad excessive.

To be clear - the setup seemed to be working OK. Not great, but it would be hard to pin the reason for that down. 

The TAIL/STUFF bits are from BOTH Motorola and Harris playing with the P25 protocol to extend it in ways which are not part of the standard that THEIR RADIOS can deal with for added functions or their take on the standard. In 99% of cases for those radios ie: Motorola on Harris or vice versa it shouldn't affect things. Same with adding Tait or some other manufactures radios.

Remember that Moto pushed their "X2" as the bleeding edge of the PII standard BEFORE it was completed. It was pretty close, and some things were made part of it.

As a lot of the tweeks to P25 PII Harris code likely came from the system in my area its highly tuned to 700Mhz. versus the VHF stuff like PA and some other areas have.

In my area the systems in question are all LSM be they Moto or Harris. The Harris one is 700Mhz. And like you show in your logs I get the same level of TAIL/STUFF bits logging.

I have zero issues in receiving these on SDRT or OP25, most assuredly the Harris system. As OP25 was the first foray into putting an eye on this fiasco. Things hum along just fine in both. OP25 is the production side for now. SDRT will take over when the complete conversion comes, which is probably first of the year after 1.5-2 years delay. OT here.... any way.

Not having any issues on Harris 700Mhz here.

The TAIL/STUFF level is about norm for Harris till some one leaks what those bits are really for! :) ;)

I have no VHF Harris stuff. The only P25 VHF is feds and its encrypted, and Moto,  and I don't even think I have sites close enough, because alot of their stuff is ISSI'd onto another system due to the crap coverage. Anyway.. so I can't test that.

But as far as Harris PII 700Mhz goes.. things hum along here. Using LSM in a simulcast is not a requirement, although it will make your life better due to the way simulcast works, but you could use C4FM and still be setup as simulcast. The interference caused just like in analog for simulcast is what CQPSK is designed to deal with so the radios work in the "mush" zones better. In alot of case with VHF that overlap may be non existant so C4FM is used.

The other wacky emissions designators are for OpenSky, EDACS ProVoice -EOL