Last Friday, June 12, 2009, was the final day for analog TV broadcasting; however, some may not be aware of two future conversion dates that will affect the railroads radio operations.
According to Railcom’s web site – www.railcom.net - the Federal Communications Commission (FCC) has mandated the separation between radio transmission frequencies in the 154 -174 MHz VHF commercial radio frequency band must be reduced from 25 KHz to 12.5 KHz effective January 1, 2013; the reduced separation between the transmission frequencies is called narrow-band channel spacing. The railroads’ radio frequencies occupy the 160.215 – 161.565 MHz part of the VHF commercial radio frequency band, and the spacing between their channels is 15 KHz. Moreover the Federal Railroad Administration has mandated locomotives in run-through and interchange service must be equipped with radios that are capable of operating with narrow-band channel spacing effective January 1, 2010.
The change to narrow-band channel spacing is dictated by the increasing demand for radio communications frequencies. If I interpret the changeover to narrow-band channel spacing correctly it includes the railroads’ radio operations along with other radio users in the 154 -174 MHz VHF commercial radio frequency band so the railroads will have to change their radio frequencies to correspond to the narrow-band channel spacing frequencies.
Just a small clairification, the only thing converting to digital is FULL POWER television broadcasts. There are still pleanty of analog translators and low power stations still analog.
Thanks for posting that, Larry–I like the numbering system they chose for the new intermediate frequencies. What interests me is, will railroads really get twice as many channels, or will they be restricted to an even smaller portion of the band?
I caught that, Larry–what I’m wondering, though, is whether the FCC or whatever other powers that be will tell the railroads that they should still only need 80 or 90 channels, and restrict them to, say, channels 6-50 and 106-150, causing a lot of channel reassignments (and meaning that the reprogrammed radios will still need only 100 channels instead of 200).
I’m guessing that more frequencies will allow a re-distribution of the channels. Right now I can listen to NS or CSX or Amtrak or who-knows-who on the same channel, depending on where I am - a legacy of numerous mergers, etc.
It might also allow some railroads to pick up some needed channels.
I haven’t heard any rumors to the effect that channels will be lost.
There is a lot of other rebanding going on - part of the reason for the move to digital TV - much of the old spectrum is headed for use in the public safety arena.
Is there a way to check this on scanners now? I bought a scanner from Radio Shack about…16 months ago or so and sometimes it receives ‘bleed over’ from other frequencies…usually when I’m trying to hear something I really want to. Is there a filter or something that will help this?
I assume the bleedover you are talking about is interference from another channel. I don’t know of any filter that can be applied to wipe out the interference
There are actually a couple of issues working here with current scanners. One is tuning, i.e. can the scanner tune to the new frequencies. This is probably true and easy to check out.
The other issue which is more problematic is something called “adjacent channel rejection” (preventing what was called “bleedover”) which is a function of the IF (intermediate frequency) bandwidth of the receiver. This is probably going to be an issue with scanners and legacy radios as well, requiring some additional frequency coordination efforts in the user community. In general, though, if this communications engineering work is done properly, the scanner users shouldn’t be impacted by the new frequency scheme in most cases, so long as their scanners can tune the new frequencies OK.
One could spend a lot of internet bandwidth going into the communications engineering details, but it would bore the crud out of almost everybody. I’ll spend a little of that bandwidth to say that there is no external filter one can reasonably use to help the adjacent channel rejection capability of a scanning receiver.
Some of those UHF 452/457 MHz bands are the Locontrol frequencies. I’ve only ever heard them described as being in the UHF 400 MHZ band. DPU fanatics take note.[wow]
There’s a reason why some folks espouse the wonders of using Ham radios as railroad scanners - they are a better quality radio than your average scanner. That will include adjacent channel rejection as well as general overall sensitivity.
The problem is that a ham radio can be set up to transmit on those frequencies as well, something that is at once dangerous and illegal.
And not all bleedover comes from railroad sources. The local taxicab company (to pick a random example) could cause you no end of grief is their antenna is close enough to you and carries enough power.
A handy frequency to listen to is the EOT channel (457.9375 or 452.9375). It’s relatively short range as compared to the VHF-High railroad radios, but those little data bursts (you won’t hear any voice there) will tell you a train is within 3-5 miles in most cases. It might not be as useful if there are several lines in the area within radio range but not visual range, but if you’re watching the only game in town, it could help you get your camera ready.
Larry, most, if not all ham radio equipment cannot be used for transmitting outside of the ham bands. 20 or more years ago, if you could hear something, you could call it, no matter where, but not any more. For instance, I can listen to CSX on my 2 meter transceiver, but cannot transmit there. FWIW, my ham transceiver runs rings round my scvanner…
'Xactly. For that matter, commercial grade two-way radios can be had very easily. Just don’t get caught transmitting on frequencies you aren’t licensed for (which for the average citizen is any of them).
I’ve also seen discussions about the railroads going digital, digital P25, and even encrypted, none of which bode well for the scanning community - at least until digital scanners become more widely available (and cheaper).
Sounds like my old Radio Shack/ Uniden 16 channel scanner is gonna be just a fancy weather radio someday![|(]
Is there a website with the latest RR frequencies? My Compendium of Railroad Frequencies book is somewhat out of date…was the 1st edition right after the BNSF merger! Actually I think it was the last edition printed - I’ve never seen it since.[sigh]
Why would they use encrypted? And why not agree on some digital format now? I don’t see how it would be so hard to decide on a standard in the near future…
Encryption is up to the user - perhaps they feel that it would be better if unknown persons weren’t able to listen in. The unfortunate side effect is that railfans are unknown persons as far as they are concerned. (Cue the “they’re not there to entertain us” point of view.)
I know of a sheriff who selected a trunking technology specifically because it’s not scannable at present. He really wants to keep his comms to himself. Add encryption to that logic and you’ll never know when you local cops are headed for the doughnut shop again.
There are digital standards - the best known is P25, which is not proprietary. The scanners are still a bit pricey, but I’m sure they’ll come down as production ramps up.