Unitrunker and new P25

[Comint]

A new 165-168 MHz Trunked Radio System is being rolled out in my area (QLD, Australia), and while supposedly P25, the Control Channel doesn't sound quite like others that I have heard.

At present it appears to be only used by the Installation Team, and there is very little traffic, and while UniTrunker (22) has decoded a WACN, System ID, and Channel Plan, the Log shows a lot of discarded messages. UniTrunker sometimes interprets the modulation as C4FM, and sometimes as CQPSK.

The Site is putting in quite a strong signal, as I am only about 2.5 miles away, line-of-sight, but UniTrunker does not see it that way - see attached image. I get the same results with two different scanners - Disc Taps on a UBCT9 and a PRO-2004.

A UBCD996T appears to trunk-tracks the Site, but as the usage is so low I haven't managed to catch any Talkgroups yet.

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Comint

 

[SCPD]

Hi Comint,

Is that coming off the Middle Ridge site?

I can't get new cc's from where I am for the Ergon system as yet (in the MPT coverage area) but will keep searching for them...

 

[Comint]

Hi Comint,

Is that coming off the Middle Ridge site?

I can't get new cc's from where I am for the Ergon system as yet (in the MPT coverage area) but will keep searching for them...

The Site has only had a signal on it since 2011 Dec 21, and I believe it is the first Site, so there is not much to search for at this stage.

The System is supposed to eventually have close on 200 Sites, so there is a long way to go.

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Comint

 

[SCPD]

There are two issues here.

1. Unitrunker is optimized for the Motorola flavor of P25.

2. When C4FM and CQPSK decoders perform at roughly the same level, the program thrashes between the two. This causes the site window to pop up unnecessarily. The health bar may also blink.

The C4FM decoder was greatly improved last year so #2 is a relatively new problem. The waveform looks very much C4FM. For #1, Motorola was the only player for a long time. Other vendors added their own interpretive twist to the standard. I'm still learning the subtleties.

Comint - please make a WAV file (or even MP3) recording of the discriminator audio and email to me. Who is the vendor?

 

[Comint]

When C4FM and CQPSK decoders perform at roughly the same level, the program thrashes between the two. This causes the site window to pop up unnecessarily. The health bar may also blink.

Unfortunately, I'm not always sitting in front of the screen, so I don't know how often it is happening. Most times when I start the program it comes up as C4FM, but I have seen the modulation showing CQPSK a few times.

Comint - please make a WAV file recording of the discriminator audio and email to me.

20 second clip sent.

Who is the vendor?

Tait Radio Communications. Don't know what models.

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Comint

 

[andras11]

Hey guys, am extremely impressed with the UniTrunker software....looks like this has been a labour of love !!