SDS100/SDS200: SDS100 ignoring all private calls?

[ve3tuk]

Hi Group,

I am seeing frequent private calls on a (Harris?) P25 system by way of DSD but the SDS100 seems to totally ignore these. As recommended previously in the forum, I have added the wildcard talkgroup "i0" to the scan list, and also made sure it is not in avoided state and that the service type is enabled for scan. I have enabled ID search mode. Still the radio does nothing when private calls occur. In manual mode I can tune the radio to one system frequency and wait for a private call to occur there, and then the radio will play the call and report the transmitting unit id as the TGID. So I tried adding some frequently seen unit ids to the scan list, both as units ("i12345") and tgids ("12345") and yet, calls with those units are ignored by the radio in scan mode. Any idea what I could be missing?
(Maybe the system frequencies must be scanned as conventional P25 in order to find these calls on this kind of system...?)

Thanks,
Russ

 

[Ubbe]

(Maybe the system frequencies must be scanned as conventional P25 in order to find these calls on this kind of system...?)

Yes, that's it.

When a private call take place in a trunked system of any kind the information are sent out on the control channel for the receiving party to respond to it and the private call then take place on a voice channel. It doesn't send any more info about it on the control channel as there's no longer anyone that needs that info, except scanners. So you will have to decode the control channel data just when that private call are started.

If you scan the voice channels, as you do in a conventional system, you will hit that voice channel and decode it as a private call as long as it is active.

/Ubbe

 

[ve3tuk]

There's the rub. Even with only this one system in scan, when there is no voice activity currently in progress and then a private call begins, the radio ignores it. In this circumstance I would assume the radio is constantly monitoring the control channel and should catch a call start. I ran a discovery session on this system for a couple of hours today and it didn't log any private calls, although many occurred.

 

[Ubbe]

Discovery uses the settings from the programmed system. If normal scan doesn't catch any private calls then neither will Discovery.

Check that you have at least one Unit ID programmed as leaving either TG or Unit ID blank will probably generate a known bug.

/Ubbe

 

[bearcat]

I do not know how old your Harris system is, but some older ones used Implict trunking. Upman had the firmware updated so the radios would at least track the system properly. If memory serves me correctly he stated private calls would not work. EFJohnson used implicit also. On those systems radios other than EFJ could not make private calls. This took place around the time of the 396xt.

At one time I monitored an EFJ implicit system just fine but the private calls would not come through. This is not the fault of the Uniden radio EFJ was not following the APCO P25 guidelines to tee. The same may apply to Harris
Just a thought.

 

[bearcat]

I should add at the time Procomm96 was showing a private call in the data stream just like you are seeing with DSD. We did not have DSD back then.