HELP!!!400MHz System

[KB8UYC]

Hi all,

We have just found a new system that has came online sometime within the last week. It is in Milan Michigan. We need someone in the Ann Arbor or Ypsilanti area that has TRUNKER to get a hold of us and help us out. So far what we have is this:

406.225-CC and is a 3600baud system(Digital)Motorola(sys ID withheld till we can figure out exactly how this system works!)

407.050
407.650
408.100
408.325
410.525
410.200
414.600

these are the only channels that we have seen pop up. There could be more but I have not seen them yet. I can here the digital voice in conventional mode but when I trunk track the CC it pops up with the Talkgroup id and frequency but no audio! So, if anyone can help us we would greatly appriciate it!

Please either contact me by email or Thunderbolt by email. Thanks

Eric-KB8UYC

 

[gpp10x]

Help!!! 400mhz system

Thunderbolt & Eric Carlson have the system identified as the Federal Prison in Milan in the database with some of the freqs you listed.

 

[KB8UYC]

gpp10x

I am currently aware that it is listed here. Thunderbolt put it there a little bit ago. What we are trying to figure out is why we cannot trunktrack it. In Conventional Mode we hear the Digital Audio just fine, but in trunktracking mode we get the ID's but no audio. BTW, Eric did not help with the system. It has only been a few of us around the Ypsilanti area to get all the info

 

[Thunderbolt]

So far the only system traffic I am hearing is on:

406.225cc
407.050
408.100
408.325 (CC last night)
410.525

I have tried numerous base frequencies, offsets, etc., and no luck at all with this system. :roll: Anyone who might happen to have TRUNKER software, this would provide an interesting challenge for you, and I think we would appreciate your assistance. :wink:

73's

Ron

 

[gpp10x]

Help!!! 400mhz system

Ok, I saw Eric's name listed in the "Last Updated" box with a time stamp of 20:00. Thats why I credited him in addition to Thunderbolt. I think your 1st message was time stamped 8:25pm. Sorry I can't help out since I'm probably too far away to try & help with monitoring.

 

[KB8UYC]

Today's CC is 407.0500.........still recieving it just fine in conventional mode, however when I switch over to trunk track the CC it pops up with a few talkgroups...00112 or 00096 etc but no audio, we must have the settings wrong, and I am just not up to par on these darn UHF Trunked Radio Systems. I am learning new things with this system! WOW

Still need help though

 

[detroit780]

Milan

Since it's a UHF trunked system and it's a federal UHF system I assume it's like the rest in the country and you'll need the offset. It shouldn't be too difficult to setup. Take a look elsewhere like in Ohio for the Wright Patterson System.

 

[detroit780]

Milan UHF

A quick search of the web will find many sites with the military/federal trunked sites. Below is an example of just one. As you can see you'll need the base frequency and the offset. I'd look at as many as possible and see if there is a common offset Thei one looks like the lowest frequency is the base.

406.3500 407.9500 409.7500 Base Frequency: 406.35
406.5500 408.7500 409.9500 Offset: 50KHz
407.1500 408.9500
407.3500 409.5500

 

[mikey60]

If you can get someone to do a trunker run on it calculating the base, offset and spacing is quite easy. I did that for a system out in Vegas when I was there in Feb.

Without the trunker run, it's gonna be lucky guesses to find it.

Based on the frequencies it looks like the spacing of 25 Khz is probably correct. Offset will likely be 380, so it's probably just a matter of trying different base frequencies until you find the one that works.

Start at 406.0000 and increment it by 25Khz until you find one that works. If you get to the first frequency in the system and you haven't found one that works, drop back to 12.5Khz steps, and start over at 406.0000, incrementing bu 12.5 Khz this time.

If I had known about it on Wednesday when I was passing through the area, I'd have stopped and set up trunker on it for you.


Mike

 

[DaveH]

You might get lucky with the trial and error method, but it may be a multi-range (base/offset) system,
which would compound the problem. Best to get somebody with Trunker, Treport etc.

The step looks like it would be 25KHz, or possibly 12.5kHz

Dave

 

[Thunderbolt]

On the Uniden radios, they don't seem to like 25 KHz., and prefer 12.5 KHz., spacing on this system. However, no matter what combination I use, 410.5250 MHz., will not track properly.

73's

Ron

 

[mikey60]

It's probably a multi-table system then.

Mike

 

[GlacierClipper]

They are updating alot of the federal prison radio systems. The new trunked systems are more relaible than the old 170 mhz radios.

 

[Thunderbolt]

They are updating alot of the federal prison radio systems. The new trunked systems are more relaible than the old 170 mhz radios.

That is correct, the old VHF-High band portables they had were ancient, and would not work that well from some areas deep inside the prison. However, so far the new 400 MHz., radios are have no dead spots at all and the coverage is fantastic.

73's

Ron

 

[WayneH]

I've never seen an ASTRO system use a spacing of 25kHz. Typically 12.5 or less..

Open the squelch to see what freq the scanner is going to since it switches back so fast with the squelch closed.

Sometimes the freq defs for Fed Prisons can be basic and sometimes strange. One near me has the highest freq using a second range.

-Wayne