• Effective immediately we will be deleting, without notice, any negative threads or posts that deal with the use of encryption and streaming of scanner audio.

    We've noticed a huge increase in rants and negative posts that revolve around agencies going to encryption due to the broadcasting of scanner audio on the internet. It's now worn out and continues to be the same recycled rants. These rants hijack the threads and derail the conversation. They no longer have a place anywhere on this forum other than in the designated threads in the Rants forum in the Tavern.

    If you violate these guidelines your post will be deleted without notice and an infraction will be issued. We are not against discussion of this issue. You just need to do it in the right place. For example:
    https://forums.radioreference.com/rants/224104-official-thread-live-audio-feeds-scanners-wait-encryption.html

167.925 MHz & 170.750 MHz Trunked System

Status
Not open for further replies.

ScannerSK

Member
Joined
Mar 6, 2005
Messages
1,120
Location
Gilcrest, CO
All,

I came across two trunked frequencies today however have yet to determine what system they are part of. The frequencies (167.925 & 170.750) are both in the govt. band and can be decoded with the Pro-96 in FM mode.

I just located them today and have heard some conversation however nothing to identify their location yet. I cannot locate any control channels at all in the 162-174 MHz band.

My location is 40 miles north of Denver (Gilcrest, CO).

In a separate thread I'm also trying to determine what trunked systems 407.725 & 419.900 are part of and also what trunked system 415.850 & 416.000 are part of? <http://www.radioreference.com/forums/showthread.php?t=98634>

Thx all,

Shawn
 
Last edited:

jeffreyinberthoud

Completely Banned for the Greater Good
Banned
Joined
Oct 18, 2001
Messages
1,870
Location
BERTHOUD COLORADO
Ive seen 170.750 and several athers in that range pop up on close call as I drive by the federal building in the lakewood area ,Never tried to track them just logged them
there is also a 138. something..... data freq from same
 

ChrisP

Member
Premium Subscriber
Joined
May 20, 2002
Messages
1,065
Location
Portland, OR
ScannerSK said:
All,

I came across two trunked frequencies today however have yet to determine what system they are part of. The frequencies (167.925 & 170.750) are both in the govt. band and can be decoded with the Pro-96 in FM mode.

I just located them today and have heard some conversation however nothing to identify their location yet. I cannot locate any control channels at all in the 162-174 MHz band.

My location is 40 miles north of Denver (Gilcrest, CO).

In a separate thread I'm also trying to determine what trunked systems 407.725 & 419.900 are part of and also what trunked system 415.850 & 416.000 are part of? <http://www.radioreference.com/forums/showthread.php?t=98634>

Thx all,

Shawn
Shawn, I am confused. You say you found some trunked frequencies, but you haven't found any control channels. How have you decided these two frequencies are trunked if you haven't found any control channel? Of are you saying you found 2 P-25 digital channels?

In order for these VHF frequencies to be part of a trunked system, there has to be a control channel associated with them.

BTW, 170.7500 MHz is used quite often by the US Marshals at federal courthouses.

- Chris
 

rfburns

Member
Joined
Nov 19, 2002
Messages
1,024
167.925

It seems like 167.925 should be WAPA or BOR, but I don't have my data with me to look it up. I could be wrong. What do they talk about on those two frequencies?
 

ScannerSK

Member
Joined
Mar 6, 2005
Messages
1,120
Location
Gilcrest, CO
Chris,

They are P-25 digital channels. I guess now that I think about it they would not have to be trunked. Would there even be a need for a control channel? Possibly they are stand alone P-25 channels then?

There may be an associated control channel that I'm not capable of receiving in this area?

Thanks for the heads up!

I'll try to catch some conversation on the freq's.

Shawn
 
Last edited:

ChrisP

Member
Premium Subscriber
Joined
May 20, 2002
Messages
1,065
Location
Portland, OR
ScannerSK said:
Chris,

They are P-25 digital channels. I guess now that I think about it they would not have to be trunked. Would there even be a need for a control channel? Possibly they are stand alone P-25 channels then?

There may be an associated control channel that I'm not capable of receiving in this area?

Thanks for the heads up!

I'll try to catch some conversation on the freq's.

Shawn
Hi Shawn...

Yes, if they were part of a trunked system, then there would be an obvious control channel transmitting a continuous data stream. (There are exceptions, such as LTR, but that would not apply to a system with P-25 voice channels) The transmitter for the data channel would located with the voice channel repeaters, so you would be able to receive it with the same signal strength as the voice channels you are hearing. The radios using the trunked system would have to receive that data channel in order to work with the trunked system, so it's not likely that you could hear the voice channels but not the control channel.

Once you find that control channel, you can look at the information being transmitted in that data stream using software such as Trunker, Unitrunker or PRO96COM. That would let you know what the associated voice channels are supposed to be.

VHF trunking in the federal bands is rare, but not unheard of. I guessed from your original posts that you assumed that if you found some digital voice traffic, it must be trunked. Not true...

Keep listening and see what you find out!

- Chris
 
Status
Not open for further replies.
Top