Need someone smart!!!

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mpdonala

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I have been working on a military 400 mHz trunking system.(Ft Carson CO. The database is wrong) I have run unitrunker and gathered the following info if someone could help me get this info into Base Step Offset it would be a great help. Hopefully the info will be enough to get this info. Thanks for any and all HELP.
407.7625 CC Red
1C9 BROWN
1D1 BROWN
200 RED
204 BROWN
208 GREY
210 BROWN
21D GREY
265 GREY
280 GREY
296 GREY
29A GREY
29B GREY
2A0 GREY
2A8 GREY
2B6 GREY

407.9625 CC Red
1B1 BROWN
200 BROWN
210 RED
235 GREY
265 GREY
26D GREY
2C8 GREY

This is all the info unitrunker gave. I get alot of VC's and TG's during scanning but no audio. Thanks again for the HELP! Mark
 
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SCPD

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Hi Mark;

The information you posted above is taken from the activity display so I can't see what channel number is behind each of the active control channels. From the main menu ... select [V]iew -> [C]hannels. That will display all channels for all sites. This will display the frequency and channel numbers in separate columns.

To make the job even easier (less typing), you can post your HZ file here.

If you can confirm two channels on each site ... someone here can help with suggesting a bandplan (base frequency, channel offset, and step size). You've got multiple brown channels - those are alternate control channels. If the system rotates control channels each night ... just wait a day and you'll have a second channel.

Once you do have a band plan, you'll need to confirm each channel. The system may require multiple table entries.

-rick
 

mpdonala

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????

I have tried to view the channels and all it shows is zeros am I doing something wrong?? This is getting frustrating.Thanks Mark
 

SCPD

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mpdonala said:
I have tried to view the channels and all it shows is zeros am I doing something wrong?? This is getting frustrating.Thanks Mark
Let's try this ...

With the program running and tuned to the above system ...

1. back out to the main menu (if not already there) by pressing the [Esc]ape key.
2. Type [F]ind -> [C]hannel to get the channel finder menu.
3. Type in the LCN of the active control channel (the one highlighted in red) and press Return (or Enter).
4. Press the tab key until the frequency field is selected inside brackets [ like this ].
5. Type in the frequency of the control channel (should match your radio).
6. Type Alt-S to save.

You're now half-way there.
 

SCPD

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mpdonala said:
ok i did that and it is not saving I tried alt +s and ctrl + s and nothing.
Were you able to enter a frequency?
Does it appear in red in place of the control channel number?
-rick
 

SCPD

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mpdonala said:
I can put in all the info at the bottom but it is not saving it!!
*scrathes head*

The menu bar should look something like ...

Channel: ave [A]pply nsert [D]elete [Esc]ape

So ... AFTER typing in the frequency ... press the TAB key. Repeat pressing TAB until one of the menu items listed above is highlight. You can backup by pressing shift-TAB. Pressing ALT is supposed to kick the cursor directly to the menu bar. Once one of the menu items is highlighted - type the letter of the menu item you want (in this case, an "S").

-rick
 

SCPD

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mpdonala said:
All I get is Find a Channel: [Esc]ape!
That explains it. The next step would be to fill in the channel # of the active control channel in the "by LCN" field. That would have taken you to the channel entry for this system. Insert will work but you have to be careful that you don't insert junk into your list of channels. Speaking of junk, you've got a duplicate channel. I see channel 210 listed twice - once it each site. Use the find ... channel steps described above and select the [D]elete menu option to remove the unwanted channel.

By your subsequent post, you've got it filled in - good.

Next step is to figure out the frequency for at least one of the other channels.
 

SCPD

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mpdonala said:
How do you do that?
Good question. Here are some ways to do that ...

1. wait for the system to roll over to one of the alternate control channels.
2. scan for the voice channels with a separate radio. During low periods of activity when there's at most one call active at a time - you can scan for the one active voice channel. If there are other systems in the area on the same band, you'll have to figure out how to distinguish the channels from this system and the rest of the world.

Some systems might rotate control channels a few times per year. Other systems do so several times per day. #2 above will take some effort. It's really two steps ...

2a. scan for voice channels. Write them down. Use the person's voice to distinguish channels. If you hear the same person's voice on two channels - those channels probably belong to the same system.

2b. program your list of channels into a second radio. When you see a call appear on the Unitrunker activity display, press "scan" on the second radio. Try to correllate the channel number with the frequency "hit" on the second radio.

Once you've matched channel # "X" with frequency "Y", edit the channel entry in UniTrunker, lock the channel out from your second radio, and watch for new calls that pop up on the remaining channels. Once you've gotten all the channels down ... go back and verify each one. Eventually you'll recognize some of the voices and associate them to a particular talkgroup or radio id. That will help speed up the process of confirming channels.

This is roughly how EDACS, LTR and UHF/VHF systems are mapped out in the database.

-rick
 
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mpdonala

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More info PLEASE help!!!

I am trying to get Base Step Offset. Here is the info I have at this time.

CC 407.7625
1C9 BROWN
1D1 BROWN
200 407.7625 RED
204 BROWN
208 410.4625 GREY
210 BROWN
21D 410.7250 GREY
265 411.6250 GREY
280 411.9625 GREY
296 412.2375 GREY
29A 412.2875 GREY
29B 412.3000 GREY
2A0 412.3625 GREY
2A8 412.4625 GREY
2B6 412.6375 GREY
2C8 GREY

CC 407.9625
1B1 BROWN
200 BROWN
210 407.9625 RED
235 411.0250 GREY
265 GREY
26D 411.7250 GREY
2C8 412.8625 GREY

If more info is needed please let me know what is needed. Thanks for all HELP!!!!
 

SCPD

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mpdonala said:
Come on someone knows how to decod this. PLEASE help or tell me how to figure it out. Thanks Mark
Hi Mark. How did you get those frequencies (the ones above 410 mhz) ? Did you type those in or were those the result of attempting to set a bandplan?

Try this ... (I'm guessing both sites use the same plan - which may be wrong).

Step = 12.5 khz
Offset = 380
Base = 407.7625 - 0.0125 * (512 - 380) = 407.7625 - 1.650 = 406.1125 mhz

The above formula should line up for control channel 200 (decimal 512) and control channel 210 (decimal 528). Note: if you don't like working with hexadecimal numbers, go to the options menu and set the display mode to "Decimal".
 
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mpdonala

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I actully put the scanner in scan with trunker running and when the line lit up on unitrunker I worte down the freq that it showed. I verified it several time when that situation occured and everything was the same each time so I added the freq like you told me thanks I'll give it a try. So are you saying it is the same base step and offset for both sets??? Thanks Mark Could you give a break down on your equation I am trying to figure it out. Thanks
 
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SCPD

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mpdonala said:
I actully put the scanner in scan with trunker running and when the line lit up on unitrunker I worte down the freq that it showed. I verified it several time when that situation occured and everything was the same each time so I added the freq like you told me thanks I'll give it a try. So are you saying it is the same base step and offset for both sets??? Thanks Mark Could you give a break down on your equation I am trying to figure it out. Thanks
Wow ... very impressive.

Oh crud.

That means this is likely a multi-table system. You will need two or three table entries for each system. It also looks like the tables will be different for each site. Sorry Mark, you picked a hard example. Let's deal with one site for now ... there one where CC == 407.7625 mhz.

There's a big jump in frequency from channel 200 to 208. Delete channel 210 from this site. It belongs on the other site.

Keep the other base/offset mentioned above. The LCN Low will be 380 and the LCN hi will be 519. Suppose the second table will start at 520. Here's why: let's use channel 208 as the start of the second table. 208 hex is 512+8=520 decimal. The frequency at this channel happens to be 410.4625. We'll use that as the base. Need a guess for the step size. The next channel after 208 (520 decimal) is 20D (512+13 = 525 decimal) at 410.7250 mhz.

The distance in megahertz between these two channels is 410.725 - 410.4625 = 0.2525 mhz which is the same as 252.5 hz. The distance in channel #s between these two channels is 525 - 520 = 5. That would suggest a step size of 252.5 / 5 = 50.5 khz - which is a very unlikely step size. We're looking for something like 12.5 or 25 khz. We'll set aside this channel for now and look further down.

The formula for a bandplan table entry ... takes the channel # from the control channel to calculate a frequency.

The formula is Freq = Base + (channel # - offset) * step.

There's more info on the Wiki (I'm too lazy to type out more).

I'm guessing channel 525 is suspect (perhaps not the correct frequency). Looking further down though ... look at channels 29A and 29B. Those are right next to each other and with a difference of 12.5 khz. That suggests a rational step size for at least these two channels.

Look at channels 2A0 and 2A8. These have a channel distance of 8 and a frequency distance of 0.1 mhz. Divide 0.1 mhz by 8 gives you 0.0125 mhz - or 12.5 khz. Another good sign.

We know they have the same step but are channels 29A, 29B, 2A0 and 2A8 in the same table (have the same base/offset)? Plug in some numbers to see if it works. Use channel 29A as your base and offset.

Base = 412.2875
Offset = 666 (aka 29A in hexadecimal)
Step = 12.5 khz

Plug channel 29B into the above formula ...

Freq = 412.2875 + (667 - 666) * 0.0125 = 412.2875 + 0.0125 = 412.3000 mhz.

Does that match 29B ?

Plug channel 2A0 into the formula ...

Freq = 412.2875 + (672 - 666) * 0.0125 = 412.2875 + 6* 0.0125 = 412.3625 mhz.

Does that match 2A0 ?

You may want to play around with using 280 or 265 as the base / offset. It may include all of the above channels plus lowered number channels. This isn't definitive but should put you closer (give or take a channel).

-rick
 
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