Lancaster County Dumping Low Band Paging

[GTR8000]

To clarify, the Unication G4 and G5 (and presumably the upcoming G2 and G3) will decode QCII tones over P25 conventional or trunking (FDMA or TDMA). There is no special signaling involved, no control channel data (other than the voice channel grant), and dedicated individual talkgroups are no longer required. They function the same way a Motorola APX would with QA09000 Digital Tone Signaling, by decoding the tone frequencies themselves as an analog radio would.

From the Motorola APX Radio Software catalog:

DIGITAL TONE SIGNALING
Reduces response time by alerting entire groups of responders
simultaneously. Commonly used in Fire Rescue to alert first responders
to an incident by broadcasting a series of distinct, recognizable
tones followed by a voice transmission from dispatch. This allows an
entire fire department to be simultaneously alerted to an emergency
situation, as opposed to unit-to-unit dispatch (Call Alert). Responders
can keep their radios in a quiet or silent mode until an alarm is raised.
This feature works on P25 conventional or trunked systems, providing
digital Quik-Call II operation (identical in operation to the legacy analog
version). The feature supports encode from an APX portable or mobile
with a DTMF keypad from release 7.17.5.

 

[GTR8000]

One last clip. This was recorded from the same TDMA talkgroup using a 536HP (so as not to favor the APX), and also includes some DTMF tones.

Vocaroo | Voice message

 

[gfisher]

Thankfully very few tones need to be changed and they are only being changed because the fall within the same tone freq group that unication uses

 

[phillydjdan]

Bucks County also uses 2-Tone over P25 and it sounds very crisp and clear, although some lower frequencies do exhibit a bit of warble. The Unication pagers actually dont use the EXACT 2-tone frequencies, but rather a small range of frequencies for each tone. So (as an example) instead of programming your A tone to 623.7 you choose range 614.8-648.1 and for your B tone instead of 1492.8 you choose range 1478.5 to 1501.7. I have had my G5 programmed this way for 2 years and 16 different tone sets and it trips every time. Keep in mind though, that the dispatch center needs to have a good quality talkgroup setup. Bucks uses a console patch. Folks like New Castle County, Delaware use a different kind of patch that sounds like utter garbage and I imagine tones won't trip on that one.

 

[ocguard]

I'm not trolling or breaking balls, but am genuinely curious why you consider talkgroup voice dispatch the "correct" way. I assume you're referring to the original method the Unication pagers required, which was a dedicated talkgroup for each agency/alert? Or are you talking about conventional P25 vs trunking?

I think the real reason that group calling is the "correct way" over two-tone is air time and speed. Airtime on a P25 system can be valuable. To be able to multi-select appropriate dispatch groups and send the message. With the integral, high-speed data and signaling capacities of a P25 system, the concept of sending analog signals over voice channels seems borderline ludicrous.

 

[Twister_2]

I think the real reason that group calling is the "correct way" over two-tone is air time and speed. Airtime on a P25 system can be valuable. To be able to multi-select appropriate dispatch groups and send the message. With the integral, high-speed data and signaling capacities of a P25 system, the concept of sending analog signals over voice channels seems borderline ludicrous.

I think there are multiple better ways to do paging than QC in 2019.

 

[jim202]

A major problem with many agencies that are sending paging tones out over a p25 system is that the audio levels are too high and causing the problems due to distortion. This was a common problem on analog systems, but is critical with p25 paging. Most radio techs either just don't give a hoot or don't know any better on setting the page tone level.

Jim