P-25 Digital Heard In The Detroit Area

[Thunderbolt]

Over heard three radios talking in P-25 digital mode, conducting range tests on 160.545 MHz in the Wayne County/Detroit area several minutes ago. The users were comparing the range of P-25 to that of analog.

My question is, who uses 160.545 MHz in the Detroit area? I suspect that it was NS, but could not confirm it, as they did not ID themselves over the air. However, they did mention Wayne Jct.

73's

Ron

[MacombMonitor]

Wow...didn't know railroads were going to digital!

[ac7xc]

Here in Portland Oregon the RR is P25 and trunked.

[Thunderbolt]

Originally Posted by MacombMonitor

Wow...didn't know railroads were going to digital!

NS and UP have been experimenting with P-25 technology for data and voice transmissions, since the mid-1990s. Moreover, the latter of the two plans on switching over to complete conventional P-25 operations, with trunking being used in the large cities. However, I would not hold my breath for this to happen anytime soon, especially with the economy in a down-turn the way it is. Likewise, the pressure to make the switchover to P-25 has subsided for a while since the mandatory "narrowbanding" process has been delayed for a few years.

73's

Ron

[jpryor]

NS Railroad PD use that frequency down here in Toledo. Possibly it's NS PD and they're playing with some new radios. I have not heard any P25 Railroad in my area though.

[DPD1]

I was under the impression that they were only looking at using it on secondary systems, like car dept., PD, Maint., and so on. If they actually do use it on the road channels someday, it would be a huge and very expensive undertaking... And frankly, I can't see any logical reason to do it. Of course that never stopped a company from doing something.

Dave
-DPD Productions - Featuring the TrainTenna LP Gain RR Scanner Antenna-
http://eje.railfan.net/dpdp/

[wa8pyr]

Originally Posted by DPD1

I was under the impression that they were only looking at using it on secondary systems, like car dept., PD, Maint., and so on. If they actually do use it on the road channels someday, it would be a huge and very expensive undertaking... And frankly, I can't see any logical reason to do it. Of course that never stopped a company from doing something.

Huge and expensive not only because of all the new radios they would have to buy, but also because of all the new wayside base radios that would have to be installed. To get the same effective (ie, usable) coverage with digital, I guesstimate that they would have to add 25% more wayside bases, and relocate the ones that are already out there.

Tom WA8PYR

[DPD1]

A few days ago, I saw an FCC document posted, that apparently shows that AAR "devised a plan to transition to 12.5 kHz technology by the Commission-required date (January 1, 2013)"

So apparently this is another wonderful commission driven switch... By their own admission, the AAR says: "Managing this conversion will be an enormously complex and difficult task".

I guess Motorola wined and dinned the right FCC members.

Dave
-DPD Productions - Featuring the TrainTenna LP Gain RR Scanner Antenna-
http://eje.railfan.net/dpdp/

[Josh]

Right now, the radio base stations are set up close enouhg (if not everywhere, but my area) that they wouldn't need any more bases to keep up on digital.

Digital works great anyhow, the differences in usuable signal in analog is about the same as digital- just that in digital you don't have to listen through all the static....

railroads keep the squelch on their radios tight, and overbuild their infrastructure enough so that if one radio site goes down communications still goes uninterrupted. From my house, with an antenna on a 20' pole, I can RX trains from several dispatch bases away. I don't think portable coverage is what they were expected to provide in their build-outs either.

-Josh

[Thunderbolt]

Originally Posted by DPD1

A few days ago, I saw an FCC document posted, that apparently shows that AAR "devised a plan to transition to 12.5 kHz technology by the Commission-required date (January 1, 2013)"

So apparently this is another wonderful commission driven switch... By their own admission, the AAR says: "Managing this conversion will be an enormously complex and difficult task".

I guess Motorola wined and dinned the right FCC members.

Dave
-DPD Productions - Featuring the TrainTenna LP Gain RR Scanner Antenna-
http://eje.railfan.net/dpdp/

I do know that NS is now buying radios that can be easily converted to the new narrowband standards and are fully P-25 compliant. According to the director of communications at NS, they want to be ready for the changeover when it comes and all new equipment will be fully compliant with future FCC Regulations. That said, this is going to really change the way we listen to railroads in the future.

73's

Ron

[DPD1]

Apparently the plan involves trunking as well... Not sure how that's going to work.

Dave
-DPD Productions - Featuring the TrainTenna LP Gain RR Scanner Antenna-
http://eje.railfan.net/dpdp/