Help , newbie !!!!

[aidob]

Hello everyone , this question might have been answered already (I had a look through some of the message but , they didn't fully answer my query) but I am having trouble with Trukito sending me to the wrong frequency .

I am here in Dublin , and Dublin Airport , along with Dublin Bus operate MPT 1327 systems . The frequencies allocated for these systems in Ireland are 425.775 - 428.9875 , but when monitoring the control channel on 428.425 (Dublin Bus control channel) , it was sending me to frequencies in the 171 mhz range, and in the 436 mhz range .

I think my main problem is , how do I edit the .ini file , for my needs .

I know one of the frequencies it sent me to (436.675) was supposed to be 426.050 . So any tips on how to edit the .idi file (especially using the offsets , I don't understand them ) .

Oh yeah , I'm using the windows version of Trunkito ,

Help please ...

[Jay911]

You need to figure out which is the right base/offset/etc for your system. I'm no expert in that field, but I'll try to help you based on what I got for the system I monitor.

The system I monitor has frequencies of 424.1625, 424.2625, and 424.5125, and reports them as GTC's 333, 341, and 361 (decimal), which equals 14D, 155, and 169 hex.

My trunkito.ini looks like this:

[MPT1327]
BASE=4168750
OFFSET=252
STEP=125

What this means is that the frequency we'll start counting at is 416.8750. Each frequency, or channel, is 0.0125mhz apart (so the next one is 416.8875, and then 416.9000 after that), and channel 'zero' in the system is actually 252 channels "above" 416.8750.

(I suppose the values could also be BASE=4200000 and OFFSET=0 - but as I said, I'm not exactly intimately familiar with this form of trunking.)

In any case, using the file as outlined above provides me with the right frequencies and GTC's in Trunkito.

Having said that, I'd have to know what GTC channel IDs you're getting, and all the frequencies you have for your system, and then I should be able to figure out the right base and offset for you.

You probably did what I did when I first got Trunkito - you put the lowest frequency of the system you're monitoring in as the BASE. For whatever reason, that's not the way these trunk systems work.

Yup. From the information you've provided, I can see that the base is 10.625 mhz off. So if it says BASE=4257750, make it BASE=4151500 instead. You should then get 426.050 when you expect 426.050.

I'm willing to bet you originally got 172.9625 on the same channel.. the default ini file starts with a base of 162.0625.

That should clear up your frequency issues. However, if seeing the right Go To Channel is important, it will take more work. You'll have to figure out what exactly the channel number is for, for example, 426.050, and then count backwards until you reach 415.000. At least, I think..

[morfis]

From an earlier thread

<-----Quoted Text----->

Frequency = Base + (Channel + Offset - 2) x Step

The Offset default value (used when it isn't defined in the INI file) is 2, so putting it at 2 or not putting it at all is the same and in this case the above calculation simplifies to:

Frequency = Base + Channel x Step

<-----Quoted Text----->

Make a note of the channel numbers and confirm the real frequency that each relates to.
The step size for your nets is 12.5KHz so:
known freq-(known channel number*0.0125) = base freq in MHz

Use the calculated base freq (without decimal point) in the ini file in a section using the relevant sysid. You will end up with something like:


[0x1e09]
Beginofband=1708000
Offset=2
Step=125
CChFrequency=1773125
Name="St Helen's Council"

Actual wording will depend on the version of the software you are using.

add a second ini entry for your other networks by calculating things the same way.

Bear in mind that this will only work for systems with a logical channel plan.

Tigger

RADIO REFERENCE IS A SHIT HOLE!