AAR Narrowband Migration

[dispatcher812]

Originally Posted by johnnymitch74

as for me, i notice no difference between the wide and narrow transmissions.

Same here. I am using a BC350A to host a feed and I think its BETTER sounding and more clear. (probably just me). I also noticed that I was able to pick up the hotbox better then before.

[TelcomJunkie]

You shouldn't have noticed a difference from Dec 31 2012 to Jan 01 2013, it wasn't like a narrowband switch was flipped. The railroads made the transition over the last two years. On the local BNSF subdivision the dispatcher radios converted to narrowband back in mid-2011 and the crews slowly migrated over the end of 2011/beginning of 2012.

[PJH]

Ha. I was waiting for someone to post that. It's always neat to see how the human brain process specific information and timelines.

[dispatcher812]

Originally Posted by TelcomJunkie

You shouldn't have noticed a difference from Dec 31 2012 to Jan 01 2013, it wasn't like a narrowband switch was flipped. The railroads made the transition over the last two years. On the local BNSF subdivision the dispatcher radios converted to narrowband back in mid-2011 and the crews slowly migrated over the end of 2011/beginning of 2012.

Maybe that is the way for the BNSF, but not here. At the end of December, I heard the dispatcher talking to the crew about it. The trains themselves were Narrow while the Dispatcher was still wide.

[PJH]

It's not like there is a button to push between wide/narrow. Someone has to physically go to the base station and reprogram it. No railroad is going to pay overtime to bring in maintainers (times x amount of maintainers) on New Years Eve to do this.

Once they get the emissions on the license and do a site visit, it's pretty much done for that reason.

Generally what railroads do it pick a section at a time, put out a track bulletin stating the radio change in progress and to use 27 or 027 as the case may be if one channel doesn't work as well as the other.

[dispatcher812]

Originally Posted by PJH

It's not like there is a button to push between wide/narrow. Someone has to physically go to the base station and reprogram it. No railroad is going to pay overtime to bring in maintainers (times x amount of maintainers) on New Years Eve to do this.

Once they get the emissions on the license and do a site visit, it's pretty much done for that reason.

Generally what railroads do it pick a section at a time, put out a track bulletin stating the radio change in progress and to use 27 or 027 as the case may be if one channel doesn't work as well as the other.

I know its not just a flick of a switch. I work in an Emergency dispatch center and we had to do ours as well. All I am saying is that, the railroad I listen to, sounds better, and the info I heard in December is what is is. maybe they sent out crew a few days before the holiday.

[radioman2001]

Hate to pop your bubble but you don't need a technician to come and do the switch at midnight 12-31-12. Any RR using Icoms (maybe Kenwood too, don't know) has the option of doing just that, pushing one button, one time and the radio reverts to all narrow band all at once.Good pre-planing is the key, and a lot of RR's have done well in doing just that.

You will always have mainly users that don't want their radios found out since they probably wern't issued that radio to start with, so those don't get done. It's amazing how many closet and lower desk drawer queen radios I have seen in the last 6 weeks. 15 to18 year old brand new radios some still in their original boxes, others are 25 to 30 year old radios that obviously havn't worked in years showing up for replacement no questions asked. Don't agree with the policy, but that's what were are doing.

On the technical side, any good radio receiver will show very little difference in quality or audio volume. Scanners will just have lower volume.

This issue in my opinion is a dead horse, all that could have been done up to now is done. Eventually all the WB radios will be found and replaced or reprogrammed and or retired. Just like the one I found in 1973 that was still a 50khz radio, that was supposed to have been changed out in 1959.

Now on to other bigger issues, like PTC. That's looming for completion by 2015.

[TelcomJunkie]

Originally Posted by radioman2001

Hate to pop your bubble but you don't need a technician to come and do the switch at midnight 12-31-12. Any RR using Icoms (maybe Kenwood too, don't know) has the option of doing just that, pushing one button, one time and the radio reverts to all narrow band all at once.Good pre-planing is the key, and a lot of RR's have done well in doing just that.

<snip>

This issue in my opinion is a dead horse, all that could have been done up to now is done. Eventually all the WB radios will be found and replaced or reprogrammed and or retired. Just like the one I found in 1973 that was still a 50khz radio, that was supposed to have been changed out in 1959.

Now on to other bigger issues, like PTC. That's looming for completion by 2015.

I have seen portables and mobiles with that capability but not the base stations and even then it only applied to radios that had a specific firmware in them that supported it.

Your last statement is more likely why people have heard better audio in the last year. During the narrowband migration a lot of older equipment, especially base stations, got swapped out for brand new gear.

[JASII]

DPD Productions - Railroad Frequencies: New 12.5 kHz / 6.25 kHz AAR Radio Plan

I am sort of playing catch up here because I haven't really monitored railroad for a long time. I looked at the website above and saw that there are additional channels. What I am wondering is if many of the "new" channels are in use yet or have most areas continued using their existing channels? Also, are msot analog channels still running carrier squelch or is PL/DPL becoming any more popular? I know years ago the MRAS system was in use on BNSF and probably other railroads, as well. Is that pretty much long gone from all railroads around the US or are there still radio-telephone inter-connects in some places?

[TelcomJunkie]

Originally Posted by JASII

DPD Productions - Railroad Frequencies: New 12.5 kHz / 6.25 kHz AAR Radio Plan

I am sort of playing catch up here because I haven't really monitored railroad for a long time. I looked at the website above and saw that there are additional channels. What I am wondering is if many of the "new" channels are in use yet or have most areas continued using their existing channels? Also, are msot analog channels still running carrier squelch or is PL/DPL becoming any more popular? I know years ago the MRAS system was in use on BNSF and probably other railroads, as well. Is that pretty much long gone from all railroads around the US or are there still radio-telephone inter-connects in some places?

The 6.25khz frequencies are in use, just not very widespread at this time. You'll see them get put into service at the bigger yards and cities first as those are the locations where the railroads have essentially run out of room frequency wise. I know BNSF is already running NXDN in several larger yards.

Most RR's around here are still CSQ, except for a shortline that is on a leased community repeater.

The MRAS is still going strong on BNSF, though not in use as much anymore as the track and signal personnel can request track and time via the computer now versus phone/radio.

[downsrep]

I've noticed picking up transmissions from farther away now, and clearer. I have an old Radio Shack Pro 96 I thought the narrowband would affect it, but apparently not.

[RRR]

I work for a Railroad, and we have noticed that we can't pick up other locomotives from nowhere as near as far away as we could before going to narrowband.

[burner50]

Originally Posted by RRR

I work for a Railroad, and we have noticed that we can't pick up other locomotives from nowhere as near as far away as we could before going to narrowband.

That is largely dependent on band conditions

[RRR]

Originally Posted by burner50

That is largely dependent on band conditions

"Band conditions"?

The same frequencies, some same radios (the ones that could be narrowbanded) some new, the same antennas, same terrain day after day, and we aren't able to hear nearly as far as we were before

[burner50]

Originally Posted by RRR

"Band conditions"?

The same frequencies, some same radios (the ones that could be narrowbanded) some new, the same antennas, same terrain day after day, and we aren't able to hear nearly as far as we were before

The way that the atmosphere affects the radio waves.

Some days, I can hear engines 50 miles away. Some days, I'm lucky to hear them 5 miles.

Also, are you aware that using radios that couldn't be narrowbanded is against federal telecommunications law?

[DrWhoVa]

Originally Posted by downsrep

I've noticed picking up transmissions from farther away now, and clearer. I have an old Radio Shack Pro 96 I thought the narrowband would affect it, but apparently not.

That's the opposite of what I've heard from friends. They were able to pick up transmissions 100 miles away easily on WB and now barely hear a yard four miles away. Nor can they hear the DD nearby either.

Perhaps in the country it might go further (which I doubt since the transmit power is much lower than on WB) then it is in the city.

[RRR]

Originally Posted by burner50

Also, are you aware that using radios that couldn't be narrowbanded is against federal telecommunications law?

....My statement was intended to convey that we kept the radios that could be narrowbanded, then ditched and replaced the ones that could not.

Better?

And no matter rain, shine, heat of summer or cold of winter, the range is not what it once was. When you have a specific route you travel each day, and talk with a tower and/or another user at about the same distance as well, you have a good idea of where you once could talk, and where you now can't after the narrowbanding has taken place.

[burner50]

Originally Posted by DrWhoVa

Perhaps in the country it might go further (which I doubt since the transmit power is much lower than on WB) then it is in the city.

Incorrect.

A 50 watt radio transmits 50 watts no matter if the transmission is wideband or narrowband..

Transmission range is not affected by a wide / narrow signal. Transmission range is largely dependent on any number of other things including the atmosphere, installation quality, location, etc.

[burner50]

Originally Posted by RRR

....My statement was intended to convey that we kept the radios that could be narrowbanded, then ditched and replaced the ones that could not.

Better?

And no matter rain, shine, heat of summer or cold of winter, the range is not what it once was. When you have a specific route you travel each day, and talk with a tower and/or another user at about the same distance as well, you have a good idea of where you once could talk, and where you now can't after the narrowbanding has taken place.

Ah, sorry.

I misread your previous post.

[W9BU]

The issue is power density. If the output of the transmitter's power amplifier is spread over a wide bandwidth, the power density is lower which reduces the range. A narrow bandwidth concentrates the power which increases the power density and the range.

In the amateur radio service, CW (Morse code) transmissions have an extremely narrow bandwidth (less than 500 Hz) and are intelligible over much greater distances than SSB (about 3 kHz wide), AM (about 6 kHz wide), or FM (about 15 kHz wide).

The broadcast services provide an even better example. Broadcast AM is less than 10kHz wide. Given the right conditions, a 50,000 watt broadcast AM signal can travel hundreds of miles. On the other hand, broadcast TV is 6 MHz wide and it takes hundreds of thousands of watts to cover a 100-mile radius from the transmitter.

Theoretically, a narrowband FM signal should travel farther than a wideband signal. That said, the difference between a 16 or 20 kHz "wideband" FM signal and an 11 kHz "narrowband" FM signal is not really significant.