What Do You Listen To In the 450-470 MHz Part Of The UHF Band In Minnesota?

[JASII]

Probably many people around Minnesota don't monitor anything from 450-470 MHz. I know many folks are interested exclusively to public safety and focus on ARMER and, possibly, the page outs on VHF high band. Other are interested in just aviation, railroad, marine, amateur or other services. I am interested in having a general understanding of who is using what on various parts of the spectrum.

Lately, I have been doing some monitoring, both attended and unattended, in the 450-454.9875 and 460-464.9875. I have done it in the past, from time to time, over the years just to see what I can hear. Much of it in the past was analog, of course, and I would even log the PL/DPLs being used and determine who the user was in many cases. There was some LTR trunking in the past, too, often on systems that end users rented air time from.

The biggest change I have noticed lately, not unexpectedly either, I might add, is how much digital modulation there is in the Twin Cities on 450-470. Don't get me wrong, there is still some analog on 450-470, but the vast majority that I have monitored is digital modulation of one types or another. I have heard XPT, Capacity Plus, Connect Plus, etc. I have heard very little APCO P25 or NXDN. Great River Energey and Xcel come to mind, locally, as a UHF APCO P25 usaer. The database shows Action Radio and Mobile Radio Engineering as having NXDN. That matches what I have heard along with some U of M NXDN activity.

I will have to look a bit closer at all of the LTR systems shown in the database. Does anybody happen to know which are still using LTR vs, switching to a digital mode?

 

[bearcatrp]

Using my R30, I periodically scan those frequencies. Seems allot of data being transmitted. Have checked different modes on some of those frequencies with no luck. Only thing my R30 doesn’t cover is DMR so it’s possible those frequencies are DMR.

 

[citiot]

Did some searching with DV1. Mostly DMR (trunked), normal FM and a little NXDN

 

[stmills]

The LTR systems that rent air time are still in use. Many of the frequencies have transitioned to Digital as subscribers have moved to digital. The biggest fleet users - large bus companies, couriers are the big users still on analog. The analog systems aren’t even mentioned much on the sales websites of many of the Network providers.

 

[JASII]

The LTR systems that rent air time are still in use. Many of the frequencies have transitioned to Digital as subscribers have moved to digital. The biggest fleet users - large bus companies, couriers are the big users still on analog. The analog systems aren’t even mentioned much on the sales websites of many of the Network providers.

Which analog frequencies are still in use on LTR? I want to listen to one just for old times sake.

 

[stmills]

Just had traffic from some of the buses on the MRE Minneapolis System.

 

[JASII]

Just had traffic from some of the buses on the MRE Minneapolis System.

Was it analog on their LTR system?

 

[stmills]

Yes analog LTR uhf

 

[JASII]

Good to know, thank you!

 

[bearcatrp]

Can someone post a frequency that has some traffic? Want to see if my R30 can listen once I find the right setting (NDXN, etc). Is their 2 versions of NDXN? R30 has NDXN-N and NDXN-VN. Still learning these other modes.

 

[stmills]

If you are looking for an NXDN channel U of M Hospital Security is using NXDN on 453.1000. NXDN is N- narrow I believe 12.5 kHz and VN 6.25 kHz.

 

[bearcatrp]

Thanks. Will give it a try. Since getting my D220R antenna, have been able to listen more of the twin cities.

 

[fwfdengine2]

Rochester 460.625 used for fire station alerting.

 

[stmills]

Afternoon of monitoring Uhf LTR systems and found the following active:
Ancom
Action Radio 1 & 2
MRE MPLS & St. Paul
PWC.

 

[JASII]

Interesting. Thank you for posting that.

A couple of tidbits here:

855.4125 Xcel Energy, It sounds to me like it is a control channel.

856.7875 I don't see it listed on the Delta license, but it is using Color Code 1, just like the other Delta frequencies.

Stmills, are you able to listen to these two and see how your experience compares to mine?

 

[stmills]

855.4125 is in the Xcel system, this systems still rotates the control channel among the frequencies- so today it is on 860.3375

 

[kayn1n32008]

NXDN is N- narrow I believe 12.5 kHz and VN 6.25 kHz.

This is correct. They are also not compatible.

You can not decode a 6.25Khz channel using a radio set to 12.5KHz mode, and vise-versa.


Sent from my iPhone using Tapatalk

 

[wogggieee]

I was going through that portion of the band with SDR several months ago trying to figure out whos using what. I didn't get super far as I got busy with some other stuff and didn't get back to it yet. But what I did find echos most of what every one is saying. It's mostly digital of various flavors with DMR seemingly being the most common.

 

[JASII]

855.4125 is in the Xcel system, this systems still rotates the control channel among the frequencies- so today it is on 860.3375

Thank you for the reply. Now that you refresh my memory, I do recall that analog trunking works that way. I think I simply looked at the database and saw the control channel and alternates listed and took it at face value, which I know better than to do.

It is one of the "risks" so-to-speak of this hobby. Just because something is done one way on one system or in a specific area, does NOT mean it is done that way in other area.

Fire paging might be an example, the typical way of doing business around Minnesota is to use VHF high band with two-tone sequential signalling. Well, until recently, Eden Prairies was on low band. I also seem to recall somebody using DTMF for fire alerting, but I don't recall where at the moment.

 

[stmills]

DTMF - Brooklyn Park, Minnetonka, I think Burnsville, - I recall hearing at one time this was for in station alerting - such as turning on lights etc which made sense since the ones it was referring to was either a ft or duty crew staffing model