Need help figuring UHF TRS Settings

[darrendotcom]

I just got a BC298D last week and I need some help figuring the Base, Spacing , and Offset for a UHF Miltary Astro APCO 25 TRS.

The frequencies are:
407.3000
407.4250
407.5750
407.9625
408.1625
408.5625
408.7500
409.9500
410.1625
410.5625

The control channel is almost always on 408.7500

The settings I am using are:
Base: 406.000
Spaceing: 12.5
Offset: 380

I can pickup all freqs except the 3 highest :409.9500, 410.1625, 410.5625
I am wondering if there is a second set of settings for theese freqs.
Can anyone help me figure out the Base, space, and Offset for this system?

 

[DaveH]

The settings I am using are:
Base: 406.000
Spaceing: 12.5
Offset: 380

I can pickup all freqs except the 3 highest :409.9500, 410.1625, 410.5625
I am wondering if there is a second set of settings for theese freqs.
Can anyone help me figure out the Base, space, and Offset for this system?

I think you're right, there appears to be another range in use, that requires its own base/offset/spacing. There might even be a 3rd one, but not necessarily.

If you could figure out the channel number of the lowest frequency, you could use that as the 2nd offset, use the frequency as the 2nd base, and the spacing would be the same (12.5kHz). Someone would need to run Trunker or Treport software on the control channel to get the channel numbers. Otherwise, it would be a long case of trial and error with the offset.

Dave

 

[kikito]

I just got a BC298D last week and I need some help figuring the Base, Spacing , and Offset for a UHF Miltary Astro APCO 25 TRS.

I assume you meant the BC296D.

If it's a "fully" digital 9600 CC system AND you have the lastest firmware upgrades on it, you shouldn't need to have to enter any Base/Offset tables. Just enter the control channel and watch it trunktrack!

 

[darrendotcom]

Yes I ment the BC296D. That function doesn't work on UHF systems

 

[ericcarlson]

Someone needs to run Trunker on it determine anything for sure. At 12.5 kHz spacing, a system with one base/offset pair can address 4.75 MHz, which means only one base/offset pair is needed to address the frequencies you listed (but they could use more than one anyway).

-Eric

 

[darrendotcom]

If you could figure out the channel number of the lowest frequency, you could use that as the 2nd offset, use the frequency as the 2nd base, and the spacing would be the same (12.5kHz). Someone would need to run Trunker or Treport software on the control channel to get the channel numbers. Otherwise, it would be a long case of trial and error with the offset.

Dave

Ok, Thanks for the info

 

[kikito]

That function doesn't work on UHF systems

Not to get off-topic but it does work on VHF/UHF systems that are P25 9600 CC. I'm doing it as I type this!

P.S. If it's Camp Shelby the system you're talking about then, I can see in the database that it's a 3600, so it wouldn't work on that one.

 

[INDY72]

It is Camp Shelby- Motorola ASTRO UHF- 3600 KBPS using pure digital mode, with apparently multitable settings for a subsytem.

 

[BANDIT]

Try just listining to those three in conventional mode
for a while and see if there is any activity on those at all. Could be they just are not using them at this time.

 

[darrendotcom]

I have and there is activity on all the frequencies.

 

[loumaag]

I have and there is activity on all the frequencies.

Okay, then you need to run trunker and get the channel numbers. If you don't have a slicer setup, use the MTrunker32 port which you can down load from a link supplied in this thread. If you don't have a tapped radio, try it with speaker output. It won't work great, but if you are getting a fairly clear signal, you probably will get the channels since they are repeated so often. Once you get the channels associated with a frequency, you can calculate the base/space/offset numbers.

 

[INDY72]

He has a PRO-2052 *Untapped* and a new 296D..... So if he chooses to tap one.. I suggest the 2052.... Don't screw with the new toy guts yet lol.