SDS100: SDS100 Bandplan isnt correct...or is it?


Premium Subscriber
Nov 9, 2020
My SDS100 was programmed from Sentinel and has the following bandplans:
851.00625MHz / 6.25KHz
762.00625MHz / 6.25KHz

SDRTrunk reports the following band plans for the same site, shown in the image.


here's the technical question... Should I add the 12.5KHz FDMA bandplan in addition to the 6.25KHz TDMA one? Its strange because my county doesnt even use P25 Phase 2 yet, only phase 1. The control channel started broadcasting the TDMA bandplan about a year ago. But since the 12.5 is 2x 6.25, shouldn't it not matter becuase the 6.25KHz Channels will overlap the 12.5KHz channels? And with that all said, how does the SDS100 even utilize the bandplan? It knows the CC and Trunked frequencies, so whats the use for bandplan? (This is P25 Specific)

Edit: Now that I look closer at the SDRTrunk image, im kinda confused myself on why band 2 and 3 anre TDMA when the bandwidth is 12.5KHz and so is the spacing.....


Reverted to False Posting Guy
Database Admin
Oct 4, 2007
In 99.99999% of the cases, you do not need to mess with the band plan in any modern Uniden scanners for P25 systems. Leave it blank and let the scanner figure it out based on the control channel messaging.

As for the last part of your question, the scanner uses the band plan to determine the traffic (voice) frequencies. The fact that all site frequencies are programmed is irrelevant, it doesn't use those at all. If you were to create a new P25 system in the scanner, the only thing you would need to enter is the active control channel, and put the scanner in ID Search, and it would start decoding immediately.