Hi Frank,
Well, if you'd like to see it, I guess we would have to meet, unless you know another UP employee that can show you. A Superintendant's Notice issued earlier this year advises that narrowbanding will be occurring throughout the Service Unit, & that as each Subdivision is changed over, a Subdivision General Order will be issued notifying employees to change from selecting radio channels on the locomotives by entering, for example, 38 38, to entering 038 038. All locomotive radios now are programmed with both wideband (##-##) as well as narrowband (0##-0##) designated frequencies. This does NOT mean the actual center frequency has changed, they haven't. This simply means that that individual radio will now transmit a narrowband emission instead of the old wideband one.
All the notice did was advises us that the radios that the dispatchers transmit & receive on at various locations for those individual Subdivisions have been changed to narrowband. As already noted, very few of my fellow employees have a clue, no do they really care, about narrowbanding and how it affects their job each day.
So if you have a scanner or receiver that can display what type of emission it is receiving, I can absolutely assure you that when you hear the dispatcher radio transmitting on the Subdivision frequencies I referenced in my original post, you will see it is most definitely narrowband.
As for individual locomotives, I can only guarantee that MY locomotive will be on narrowband where it is required, because I am one of the very few out here hauling freight around Northern California who actually understands the concept and is complying with the companies instructions.
In addition, very few of the handheld radios carried by crews have been properly programmed yet for narrowband. So you will rarely hear a conductor or switchman on the ground transmitting narrowband.
Perhaps the reason for your disbelief in my saying that narrowbanding is upon us here locally is because you may not understand exactly what narrowbanding is, and how it will effect your ability to receive it on your scanner or radio?
All narrowbanding has done is to reduce the literal width of the carrier required to transmit the radio's emission. The effect of this is that there can now be more available frequencies for use in the particular piece or radio spectrum being used.
For example. Before I drove around train engines for a living, I drove around fire engines for a living. The State of California has three radio frequencies it has reserved for use as interoperability between fire agencies called the White channels. White one, two, & three. California has recently issued a directive to agencies using the White channels to change their programming to reflect narrowbanding & the new frequencies that are made available by doing so. White One has been for over 20 years that I used and/or monitored it set at 154.2800. White Two 154.2650, and White Three at 154.2950. The 15 kilohertz jump between these frequencies (265 + 15 equals 280 + 15 equals 295) was simply a nessasary requirement due to the limitations of radio transmitters from decades ago. They simply needed that 15 kilohertz space (bandwidth) to have a legible enough ANALOG carrier to carry my voice from my radio to the receivers radio without 'bleeding over' and interfering with the next closest frequency. With the improvment of transmitter technology over the years, a transmitter can now do the exact same job in HALF the space. Now between 154.2650 and 154.2950, you can stuff FIVE different frequencies for ANALOG use (154.2650, 154.2725, 154.2800, 154.2875, & 154.2950) and still not interfere with the adjacent frequency.
To create even more room on the radio spectrum, transmitters today can go even narrower! The 15 kilohertz space that was reduced to 7.5 kilohertz, can be split a second time into 3.75 kilohertz spacing! BUT there is a problem. ANALOG transmitters just can't shove their transmissions into that small a space. Just can't do it. BUT, a DIGITAL signal will fit in there just fine. In fact more than one would fit easily! Hence the ability of digital cell phone networks to have several subscribers talking, texting, & downloading simultaniously on their networks.
How does all of this effect you listening on a scanner? The short answer is, an older scanner or radio that was designed strictly for old wideband signals will still receive narrowband signals on the same original frequency. The audio it picks up may be a little low compared to before, but it wil still hear it. An older scanner might also have a hard time being programmed with the newer freqencies as many of them weren't designed for that fourth number (154.280 vs 154.2800).
Newer scanners can be programmed with the fourth number, as well as can decode the difference between wideband and narrowband.
As far as digital reception goes, in the railroad realm, the digital protocol of choice (and there are several to choose from) is the NXDN one that Kenwood & Icom support. As of today, no scanner available to us user types can decode NXDN transmissions. Only an actual NXDN radio can. Thankfully, due to the cost & the current lack of an official requirement to go to super narrowband digital transmissions, I seriously doubt the railroads will be digital, at least on mainline frequencies, any time soon.
Hope that explained it a little!
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