One thing that would easily explain what's going on is if that talkgroup is encrypted (the RR database would show it having a Mode of "E"). The Pro-197 will mute the audio for encrypted talkgroups so you don't have to listen to the digital noise. I believe that the Pro-96 also mutes encrypted talkgroups.
Of the GRE made radios, only the PSR800 will mute encrypted talk.
That is my biggest gripe with the GRE made radios is that they do not mute the encryption noise.
The Unidens are the only ones that truly mute an encrypted comm and also skip over it when detected. The PSR 800 will mute the audio if you selected that option but it will still stop scanning and hang on that channel (or talkgroup) until the carrier drops. It works but can cause you to miss comms on other channels or talkgroups. The way Uniden does it is the proper way as it skips right over it and keeps on scanning.
I think maybe what you are seeing is that some of the programming software (maybe all) will simply not program talkgroups with the E flag set as they are encrypted all the time so no sense in including them.
A P25 system here uses encryption on any of its talkgroups but it is only assigned to certain radios.
When you monitor that system with the Pro-106, 197 or GRE PSR500 or 600, you WILL hear the encryption sound as there is no way of turning it off or skipping over it. This makes for some very annoying monitoring of this system so I will not use the GRE made radios for this very reason even though they do a better job at decoding the system over the Unidens as it is also a simulcat system.
If someone mistakenly set the E flag here in the database for this system, you would never hear anything as it would simply not program the talkgroup when using a software app. I think some if not all do allow you to still select the E flagged talkgroups so they are programmed.
On the Unidens, all you need to do is sit on a talkgroup in the Hold mode and it will show ENC in the display when it is receiving an encrypted comm.
Not true on the GRE made radios, they will stop scanning and pass the encrypted audio out to the speaker. The GRE made PSR 800 or whatever the radioshack version is are the only exceptions for GRE made radios.
Those can be set to simply mute the encrypted audio, sound a tone and one other sound maybe like a busy signal I think but the scanner still stops scanning until the signal is dropped or you hit a button to force it to scan again.
Being as the PSR800 can detect and mute encryption really makes me wonder why they did not also add in a setting to allow the radio to also continue scanning is beyond me.
Now with all that said, if you have a way to make the PRO106, 197 or PSR500, 600 mute encryption when it sees it, please tell me how!
I really think your software simply did not even program those talkgroups and that is why you do not hear it. Ot it did but it also locked them out for you. Neither would work here as then I'd hear nothing. Most of the talk on this system is in the clear with maybe 5% being encrypted but that 5% will cause you to turn the radio off after hearing it for just a few minutes.
edit: the Pro-96 also passes the encryption sound to the speaker just like the 106, 197 and 500, 600 do.
