A few Questions about DAT & Signal Strength

[Ishmole]

I am scanning an P25 phase 2 system from outside my area on my BCD536HP. The signal strength varies from 0 to 3 bars. The DAT indicator flashes off and on. My question is does the DAT have to be on in order to receive a signal? Is if fluctuating because of signal strength changes? What does DAT mean? Does the squelch control affect what is received?

Also, when it is receiving a signal it reads PT0 and PT1. What does that indicate?

Thanks!
Mike

 

[troymail]

I am scanning an P25 phase 2 system from outside my area on my BCD536HP. The signal strength varies from 0 to 3 bars. The DAT indicator flashes off and on. My question is does the DAT have to be on in order to receive a signal? Is if fluctuating because of signal strength changes? What does DAT mean? Does the squelch control affect what is received?

Also, when it is receiving a signal it reads PT0 and PT1. What does that indicate?

Thanks!
Mike

DAT should be fairly steady in order to receive the system. From what I understand, if you are getting good reception and decoding, DAT may still "blink" at a regular interval in nearly all situations to do "housekeeping functions" inside the radio. However, with good reception, you should be able to see a very distinct and consistent pattern of the "DAT" symbol blinking on on and off.

Note: I believe if there are no priorities or other functions turned on in your radio and you either "HOLD" on a specific talkgroup or set the system/site hold time to something higher than the default 0, DAT should remain solidly lit with good reception and decoding. If it blinks under these conditions, you have fairly poor reception.

 

[Ishmole]

Thank You Troymail. I never adjusted the set the system/site hold time. Can that be adjusted to slow down the DAT blinking? The system I am monitoring is in the next county and is simulcast. I am using a 700-800 mhz directional as an antenna
Thanks
Mike

 

[scan-pa]

The site/system hold time, only effects how long before the scanner moves on to the next site/system to scan.

Sent from my SM-G935V using Tapatalk

 

[troymail]

Thank You Troymail. I never adjusted the set the system/site hold time. Can that be adjusted to slow down the DAT blinking? The system I am monitoring is in the next county and is simulcast. I am using a 700-800 mhz directional as an antenna
Thanks
Mike

Adjusting the hold time basic simply tells the scanner "find and monitor this system's control channel for <this> long" vs. the normal "check it and move on".

The hold time won't do much for you in terms of solving reception problems other than to stay on that system longer. If you're trying to scan other systems or channels, changing that setting will interfere with scanning of other programmed systems.

 

[ofd8001]

From the manual:

DAT Displays when data is received on a control channel in Receive/Hold Modes. (That means your scanner is receiving the control channel and is awaiting a channel grant. It may blink owing to that "internal housekeeping". Nothing can be done by the user to change that as it is an indicator of what the scanner is "doing".)

P25 Displays if the channel is receiving digitalized voice in Receive/Hold Modes. (You'll see this if your scanner is actively receiving digital voice communications.)

LNK Displays when data is received on a voice channel in Receive/Hold Modes. (This is not unlike a repeater's "hang time" where there is still modulation on the frequency. When that "hang time" expires, your scanner will probably jump back to monitoring the control channel and you then see DAT.)

 

[IAmSixNine]

To answer the PT0 and PT1 question, on Phase 2 systems it can use 2 talk paths per frequency. LIke in DMR its slot one or slot two.
So if your on frequency 764.0000 that one frequency can carry two simultaneous talk paths with Phase 2 so one can be on PT0 and the other on PT1.

 

[Ishmole]

Thanks you all for clearing this up!
Mike

 

[RFI-EMI-GUY]

When I scan my local City, Oviedo, which has pretty low traffic compared to the county simulcast system Seminole Florida that it belongs to, I have toggling between DAT and LNK on a steady basis.

This is when not in hold and not receiving.

I have "5 bars" but that signal icon flickers off at about same rate as the DAT/LNK flashing.

Should all that be happening?