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Astro base frequency-how do you go about finding one

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psummerhawk

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Morning all, Is there a way to find the base frequency for programming an astro trunking system? I am sorry if I am overstepping my bounds on this list. I want to be able to find the base frequency for a few systems around me and get them programmed in but to do that In need the base frequency for the systems. Can a BCD996Xt do this or is there another way to do this?


Thank you in advance.
 

CQDX

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That data is transmitted over the air for a P25 trunking system. I don't think you can extract it from a 996. However, a program such as Unitrunker will let you decode the control channel and it will display everything you need. What systems are you looking for? They've likely already been figured out.
 
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psummerhawk

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Need base frequencies for WYOlink and Colorado DTRS if possible, thanks in advance.
 

cyrus

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Durchschnitt said:
That data is transmitted over the air for a P25 trunking system. I don't think you can extract it from a 996.

Let the 996 scan the system a few times and then go into Site menu, select the site and then Ediit Bandplan.

The system will have populated the bandplans *if* the system transmits the bandplans over the control channel.
 

cyrus

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psummerhawk said:
Morning all, Is there a way to find the base frequency for programming an astro trunking system?

Are you talking about an older Motorola system or a newer 9k6 system? What bands?

See my other post for info on using a 996 on a 9k6 system.

If you're trying to do it in a Motorola system, you'll need to get a control channel decoding program. My personal favourite is Trunk88. I've tried Unitrunker several times but always come back to Trunk88.

Once you've got that, you'll need to correlate channel numbers with frequencies and then use that data to figure out the base channel and spacing.

A spreadsheet program will come in handy.
 
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psummerhawk

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I have the control channels and found a excel sheet that would tell me the base frequencies, so do I just punch in all the control channels into the spreadsheet and it gives me the base frequencies? RR has the base frequencies for the Pro-96 but when I punch them into the XTS2500 it tells me they are invalid. I am programming for the XTS2500 as well as an APX7000 VHF/800 to be able to monitor both systems when I am traveling into Colorado. I was told by Zelda that is on this list that I need to base frequencies for this programming or the scanning will not work.

Hope this helps explain what I am trying to do.
 

Magnus

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On a Motorola format trunking radio (Smartnet,Smartzone,Astro,P25) all you need to enter is the control channels in the control channel list, the radio gets the voice channel frequencies over the air. Base frequencies are only needed for OBT (vhf,uhf) trunking systems.
 

cyrus

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If its an 800Mhz system, you don't need base frequencies.
 
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psummerhawk

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The one I am using for the XTS2500 is VHF so I will need the base frequencies for this project. Thanks for all the help guys on this project.
 

cyrus

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psummerhawk said:
The one I am using for the XTS2500 is VHF so I will need the base frequencies for this project. Thanks for all the help guys on this project.

Isn't Wyolink a 9k6 system?

It probably broadcasts the bandplans over the control channel so you won't have to enter them at all.

Seriously, if you're this lost then perhaps you would be better off using a scanner.
 
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psummerhawk

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Like I said I am still learning trunked systems and part of this project is programming for several that want to be able to scan conventional and trunked without having to switch systems. This is why I am asking all the questions to make this project work.

Sorry to be a pain in asking questions.
 
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immelmen

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Isn't Wyolink a 9k6 system?

It probably broadcasts the bandplans over the control channel so you won't have to enter them at all.

Seriously, if you're this lost then perhaps you would be better off using a scanner.

Im interested to hear if anyone has ever successfully programed a Astro25 subscriber to trunk a VHF 9600 system without entering a base and spacing channel plan? I have experimented with an XTL5000 on a VHF P25 system that I KNOW is transmitting Explicit IDEN_UP_VU trunking data (ie broadcasting the channel plan on the CC). The radio will not trunk the system correctly without the correct base and spacing plan in the code plug. When the correct channel plan was in the codeplug, it trunked like a champ, but when the base/spacing where left at the default values for the one assignment row that is active by default the radio would not trunk. Also, as an interesting sidebar...the channel plan that is listed in the radio reference database for the system I was experimenting with is NOT correct. So how ever they are derived, they may work on a scanner, but when I put those values in the XTL it would see the channel grant but land on the wrong frequency for the qso.
 

Notarola

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Even if you have the correct control channel loaded no VHF/UHF trunked system will work correctly without the proper bandplan entered into the radio. It dosnt matter if the radio is a scanner, a motorola, a tait , kenwood or Icom. If you look at the OSW you will see the channel number sent. If you dont have the correct base freq/step the radio has no idea on where to go.

here is an example.

Turn right off of Howard Avenue, go 2 blocks and turn left. You want the third store on the right from the corner.

Questions
What street are you on?
What is the store you are in front of?
What city are you in?
What country.

I think you get what I mean now.
 
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immelmen

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Even if you have the correct control channel loaded no VHF/UHF trunked system will work correctly without the proper bandplan entered into the radio.

exactly what I thought. I think the scanner crowd confuses the issue because the scanners these days will self populate the channel plan based on the Explicit IDEN messages. Motorola gear does not, so the OP will need the correct base and spacing for the systems in question...and radioreff is not a reliable source for that. OP, you will need to see a code plug from a radio operating on that system.
 

cyrus

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Notarola said:
Even if you have the correct control channel loaded no VHF/UHF trunked system will work correctly without the proper bandplan entered into the radio. It dosnt matter if the radio is a scanner, a motorola, a tait , kenwood or Icom.

I'll have to disagree with you at least on the basis of a scanner

To take your analogy, imagine the control channel is the mayor of the city.

You arrive at the city and the mayor greets you once he confirms your identity.

Once that's done, he hands you a map to the city with all the streets labelled.

All a newer scanner needs are the control channels for the system. It will download the bandplans from the control channel automatically if they're broadcast.

A local P25 transit system stopped broadcasting the bandplans for a while and everybody's scanners went silent until the bandplans were entered manually m

I'll be close enough to a p25 system tomorrow to see if an xtl or APX will pick up the bandplans automatically.
 

cyrus

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immelmen said:
OP, you will need to see a code plug from a radio operating on that system.

Or use a utility like Pro96com or Unitrunker to see the bandplans broadcast over the control channel.

Much easier than getting a control channel.
 
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immelmen

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I'll have to disagree with you at least on the basis of a scanner ....

...I'll be close enough to a p25 system tomorrow to see if an xtl or APX will pick up the bandplans automatically.

Or use a utility like Pro96com or Unitrunker to see the bandplans broadcast over the control channel.

Much easier than getting a control channel.

I have first hand experience working with this. The Motorola radios I was working with did not populate the channel plan like the scanner does. I can also tell you that the channel plans listed at radiorefference, which were derived with the methods you mention, for at least two major VHF/UHF trunking systems in the DC metro are not the correct channel plans as programed into system infrastructure and subscriber units. The Radioreff plans may work in a scanner, but if you plug them into a motorola radio, its gonna be as useless as my ex wife in the kitchen.

Edit to add: the radios in my experience were XTL5000s with host R12
 
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cyrus

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I didn't say use the Radioreference bandplans. I said use a control channel utility like Pro96Com

The local P25 transit system shows up in Pro96Com as having one bandplan table entry which is number 2. The base is 380.000mhz and the spacing is 12.5khz. The transmit offset is +5Mhz and there's one slot.

My XTL has the following in table entry 3: bandwidth 12.5khz, + transmit offset sign, 5.000Mhz transmit offset and a base frequency of 380.000Mhz.

A 996XT has automatically populated Slot 2 of its bandplan with 380.000mhz as the base and a spacing of 12.5khz.

The only difference I can see is Motorola numbers the tables starting at 1 while Pro96Com and the 996XT starts with 0.

The other UHF P25 system matches perfectly as well.

I can only assume the bandplans at RR have been mangled for the GRE line of scanners or something else.

If he can pull the info from the control channel, he should be able to program his radio without jumping threw too many hoops.
 

Notarola

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I use trunk88 myself.

My analogy was assuming a non transmitted control channel system. Oh well thats the danger of being too general. LOL
 
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