SDS100/SDS200: SDS100 Bandplan isnt correct...or is it?

Status
Not open for further replies.

hruskacha

Member
Premium Subscriber
Joined
Nov 9, 2020
Messages
314
Location
Muskegon
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.

1689898222996.png

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.....
 

dave3825

* * * * * * * * * * * *
Premium Subscriber
Joined
Feb 17, 2003
Messages
8,997
Location
Suffolk County NY
Your scanner will get the bandplan when scanning the active control channel on the system.
 

GTR8000

NY/NJ Database Guy
Database Admin
Joined
Oct 4, 2007
Messages
16,158
Location
BEE00
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.
 
Status
Not open for further replies.
Top