How if find Setting Band Plan for Trunking VHF

[Voyager]

Way Chi-hi 725?

CH Hi has to be high enough to cover all the channels used. You know it's at least 721 since you have a channel 721. But, for the HI I just used the original hi since I saw no need to change it. You can make it higher if you want (if there is only the one bandplan). Actually, I just noticed you have a 736, so make it 736 or higher - even 800 would be OK to start.

Generally you want the low and hi to be as wide as possible in case there are channels higher or lower than the ones you know. That said, based on the info you have the lo/hi I posted should work as a starting point (with changing the high to 800)

 

[BorisG]

Now i scan new Channels...
On Control 146.4000
listen to any Chanel...
radioshack listen to: 146.08500 (no good!)
uniden listen to: 146.08750 (good!)

 

[Voyager]

The Radio Shack likely has the wrong bandplan values set.

 

[BorisG]

I think some information is missing
Sometimes hear only one side talks
Maybe I'm missing more Seting BandPlan
How to test?

radioshack=
ch-lo 380
ch-hi 725
base 141.3125
step 12.500

uniden=
base -> lower 141.3125 -> upper 150.8000
offset 0
step 12.50khz

radioshack the background noise of Trunking, end no put same chanel listen

Now i scan new Channels...
On Control 146.4000
listen to any Chanel...
radioshack listen to: 146.08500 (no good!)
uniden listen to: 146.08750 (good!)

 

[BorisG]

DELETE

 

[Voyager]

Could the other side be encrypted? If it is, you won't hear it.

Also, I ran the formula for the frequencies you didn't have LCNs for and came up with these:

Orig Fr / LCN / Calculated Frequency

146.165 388 146.1625
146.650 427 146.6500
146.900 447 146.9000
147.060 460 147.0625
147.065 460 147.0625
147.090 462 147.0875
147.500 495 147.5000



Something else to try: They might be using something called "transmission trunking" where each transmission is assigned a different channel. Try changing the CHANNEL DELAY setting to 0 and see if you hear the reply on a different channel.

 

[BorisG]

no encrypted some time yes listen
i think problem in BandPlan setting

 

[Voyager]

As each LCN you've provided matches up with the bandplan I posted, I'm not sure if there might be a second bandplan missing or not. It would not appear so, but are all the frequencies limited to the segment 146-148 MHz?

Here is the complete list so far: (LCN / Freq) [Note: Some of the LCNs are interpolated.]

380 146.0625
388 146.1625
407 146.4000
427 146.6500
447 146.9000
460 147.0625
462 147.0875
479 147.3000
487 147.4000
495 147.5000
503 147.6000



I wonder if the 380 is not low enough for the CH-LO.

Are both scanners hearing the same thing? But, at least you're making progress.

 

[BorisG]

As each LCN you've provided matches up with the bandplan I posted, I'm not sure if there might be a second bandplan missing or not. It would not appear so, but are all the frequencies limited to the segment 146-148 MHz?

Here is the complete list so far: (LCN / Freq) [Note: Some of the LCNs are interpolated.]

380 146.0625
388 146.1625
407 146.4000
427 146.6500
447 146.9000
460 147.0625
462 147.0875
479 147.3000
487 147.4000
495 147.5000
503 147.6000



I wonder if the 380 is not low enough for the CH-LO.

i scan only 146-148
you whant to give me new chlow?

 

[Voyager]

i scan only 146-148
you whant to give me new chlow?

You can try setting it to 0 if there is only the one known bandplan and see if anything new pops up.

 

[BorisG]

Radio Shack Sometime when listen Frequency Sound Background have Trunking sound ...

Sometimes I see in UniTrunker "Call" ...
BUT the scanner can not hear....

THX 4 ALL

 

[Voyager]

What is Unitrunker showing as the frequency? In the mean time, I'm going to review your past posts again.

OK. I think there is another table involved, as you posted frequencies of:
726 169.7125
??? 169.7375
??? 169.8625

But, we need at least one LCN (other than 726) for some of those "160" frequencies.

Likely on the 146-148 table the CH LO is 380, and CH HI is something between 487 and 725 (to be determined - it MIGHT be 535 if the top end is 148.000 MHz)

Can you give some more LCN info for the higher frequencies?

I'm already working on an initial second table for you to test.

 

[BorisG]

Yes, I'll try tomorrow

 

[Voyager]

OK. Try this as a second table... (in addition to the first - not in place of the first)

ch-lo 536
chi-hi 760
offset 0
BaseFreq 160.6375
step 12.5

And make sure the first table CH-HI is set to 535

I had to make some guesses as to the table since I only have one LCN to go on, but if the step is the same this may be pretty accurate.

BTW, IF this is correct, the other LCNs you gave without a corresponding frequency would be:

619 168.3750
647 168.7250
672 169.0375
704 169.4375
726 169.7125 (the one known LCN/Freq)

 

[BorisG]

As each LCN you've provided matches up with the bandplan I posted, I'm not sure if there might be a second bandplan missing or not. It would not appear so, but are all the frequencies limited to the segment 146-148 MHz?

Here is the complete list so far: (LCN / Freq) [Note: Some of the LCNs are interpolated.]

380 146.0625
388 146.1625
407 146.4000
427 146.6500
447 146.9000
460 147.0625
462 147.0875
479 147.3000
487 147.4000
495 147.5000
503 147.6000



I wonder if the 380 is not low enough for the CH-LO.

Are both scanners hearing the same thing? But, at least you're making progress.

OK. Try this as a second table... (in addition to the first - not in place of the first)

ch-lo 536
chi-hi 760
offset 0
BaseFreq 160.6375
step 12.5

And make sure the first table CH-HI is set to 535

I had to make some guesses as to the table since I only have one LCN to go on, but if the step is the same this may be pretty accurate.

BTW, IF this is correct, the other LCNs you gave without a corresponding frequency would be:

619 168.3750
647 168.7250
672 169.0375
704 169.4375
726 169.7125 (the one known LCN/Freq)

table 0 chlo 0 chhi 535 offset 0 base 141.4125 step 12.15
table 1 chlo 536 chhi 760 offset 0 base 160.6375 step 12.15

I TRY THIS
NO GOOD

 

[BorisG]

What information do I need to check to fix Band Plan 100%

 

[talkpair]

With one of your radios, monitor 168.99

With the other radio running Unitrunker, try to match an LCN with that frequency when you hear activity on 168.99

Repeat the process for 169.035, 169.09, 169.15 and 170.04

Listen several times on each frequency to be sure your matches are correct.

Make sure the control channel you run Unitrunker on belongs to the same site as those voice frequencies. Make sure all of the voice frequencies are on the same site as well.
This is very important. If you get these mixed up, nobody can help you.

 

[Voyager]

table 0 chlo 0 chhi 535 offset 0 base 141.4125 step 12.15
table 1 chlo 536 chhi 760 offset 0 base 160.6375 step 12.15

I TRY THIS
NO GOOD

The step may not be the same on the 160s, but I will need more than one 160 LCN to figure out what it is.

You still should be hearing the transmissions you heard that use table 0.

 

[BorisG]

If find more sites its help?

 

[talkpair]

See what this does:

------------------------------------------------------
           Low     High             Base
Table     Chan     Chan   Offset    Frequency    Step
------------------------------------------------------
  0        380      [COLOR=Red]559[/COLOR]      0      141.31250    12.50
  1        [COLOR=Red]560[/COLOR]      759      0      160.63750    12.50

Enter both tables.

The numbers in red may require some adjustments.

If there are transmissions you are missing, the scanner should still flash an invalid frequency. Write down any frequencies that flash but nothing was heard.