SA GRN trunked scanning on the BC780 XLT

The South Australian (SA) Government Radio Network (GRN) uses Motorola trunked UHF radio communications for public services including Country Fire Service (CFS) control communications, SA Police Force (SAPOL), and the SA Ambulance Service (SAAS).

 

Conventional scanners provide only frustrating snippets of conversations.

 

The Uniden Bearcat BC  780 XLT is a fairly cheap trunk tracking scanner and readily obtained second hand that is compatible with the SA GRN.

 

The trunked scanning programming process is not very intuitive.

 

 

Stage 1: a worked example using bank 1 for SA GRN scanning:

 

The first thing to do is delete the frequencies in a bank you will dedicate to trunked SA GRN scanning
 

A bank on the BC780XLT is a set of 50 frequencies, i.e. stored frequencies

 

bank 1: 1-50,

bank 2: 51-100

bank 3: 101-150, etc...

in the case of bank 1:

pressing "1" on the keypad and "E" takes you to stored frequency number 1

if you then press "0" and then "E", it will delete the frequency in stored frequency number 1

if you then hit the "MAN" = manual key, it will step you to frequency number 2

if you then press "0" and then "E", it will delete the frequency in stored frequency number 2

and you can do this until you get up to and including stored frequency number 50, if you want to delete bank 1
 

Stage 2: configuring bank 1 for motorola compatible trunked scanning

the next step is to set up bank 1 (in the case of this example) as a motorola trunking bank (I have drawn on and added to the sascan instructions here):

Step 1:  Press MENU

Step 2:  Select TRUNK DATA and press E

Step 3:  Press the UP or DOWN arrows to select the trunk bank you want to program the channels into ( you can also use the VFO knob to scroll through the banks as well). When you have you bank selected (in the case of this example, we will choose bank 1), press E

Step 4:  Press the UP or DOWN arrows to select TRUNK TYPE and press E

Step 5:  Choose the Type 2 UHF trunk type. This is type no 2 and the screen should show it as TYPE 2 UHF. When this is done, press E

Step 6: Press the UP or DOWN arrows to display "BASE CONFIG 1" and press E.

Step 7:  Enter the first GRN base frequency of 412.475 and again press E

 Step 8:  The display will change so as to ask you for the spacing frequency. Enter 12.5 and press E

Step 9:  The display changes once again to ask for the offset value. Enter 380 and press E.

Step 10:  The scanner will prompt you now for the second base. Enter 415.125 and press E.

Step 11:  The scanner will now ask for the spacing and offset, the same as steps 8 and 9. Enter 12.5 for the spacing and 460 for the offset. repeater as steps 8 and 9 above.

Step 12:  Press the menu button repeatedly to exit from this mode. Then select the first channel in the bank you selected as the trunk bank by using the manual and numbers keys as you normally would.

Stage 3: find details for your local SA GRN tower

Assuming you live in the vicinity of goolwa, your local SA GRN site is the Port Elliot tower:

SA GRN Site - Pt Elliot
Location - GRN SITE BROWN HILL CROWSNEST RD PT ELLIOT 
Lat/Long  -35 30 22 / +138 38 44

Data Channel
413.125

Voice Channels
415.125
415.625
416.125
416.625
417.125
417.625

Stage 4: program the GRN channels into the bank selected for SA GRN scanning

so, you then need to program your local GRN site, in this case, we are doing it in bank 1, which starts at stored frequency number 1:

pressing "1" on the keypad and "E" takes you to stored frequency number 1

enter

413.125

 

then press "E" to store it, then press and hold the TRUNK key for 2 seconds. A tone will sound and the display will show the M icon

hit the manual ("MAN") key to step to frequency slot number 2

pressing "1" on the keypad and "E" takes you to stored frequency number 1

enter

415.125

 

then press "E" to store it, then press and hold the TRUNK key for 2 seconds. A tone will sound and the display will show the M icon just above the most significant digit of the frequency readout

hit the manual ("MAN") key to step to frequency slot number 3.... and so on

continue doing this for the remaining frequencies for the SA GRN site


Stage 5: Try some trunked scanning

having stored the Port Elliot SA GRN frequencies, the next step is to start scanning.

Press the "SCAN" button

make sure bank 1 is selected for scanning. The row of numbers 1-10 on the LCD under the word "BANK" show you which banks have been selected for scanning. In this case, make sure "1" is selected. The other banks can be excluded from the scanning.

then press the "TRUNK" button

then press the "SRCH" button

this will start the scanner reception of the data channel, and identification of trunked "conversation IDs"

You will see things something like "MOT ID: 17584" displayed on the screen below the frequency readout during overheard conversations or data bursts.

If you hear data coming through you can press the "L/O" = lockout button while the data burst is still coming through to lock out that particular trunked conversation ID. The data bursts are likely pagers or encrypted SAPOL and the scanner can be told to ignore them in this way. After listening for a while, and locking out trunked data IDs, you'll only be left with in the clear voice traffic (See also page 48 of the bearcat manual, which pretty much says the same thing).

If you have accidentally locked out some IDs by pressing the "L/O" button during voice traffic you can clear all of the locked out IDs at once (see also page 41 of the manual if you (unlikely) want to undo a lockout of a particular ID):

To unlock all locked out IDs in a bank at once:

1. Press MENU.
2. Select TRUNK DATA - BANK NO. - L/O ID REVIEW
using L, M or VFO and pressing E, SELECT or VFO.
3. Select the locked out ID you want to unlock using L or M.
4. Press E instead of L/O in step 4 above.
5. To exit from this mode, press MENU repeatedly.


The above shouldn't take more than 10-20 minutes while sitting in front of the TV.

 

If you screw something up, you just start again.