Railroad radio repeater networks QUESTION

[1977addis]

I have a question regarding listening to train crews from afar. So I’ve been a railfan for years now, I have good commercial/ ham gear to listen and I understand that dispatchers talk to the crews on the rails via Microwave but I’ve always wondered why I can’t hear the train crews from long distances in the same way that I can hear the NS dispatchers talking from Georgia to Pennsylvania on a microwave frequency. Is there some kind of Microwave (900Mhz) frequency I can tune to so I can hear farther out? With my current setup I can get about 20 miles of coverage. Hope this made sence. Thanks all. KC3MZX

 

[alabamarailfan]

Hello,
Well, you need to consider that dispatcher transmitters are located along the line you are listening to and are often located on tall towers or mountains (or both) and operate with considerably higher power than locomotives do. It would be nothing for a dispatcher location to transmit 100 watts, while locomotives are typically limited to about 50 watts and hand-helds are about 4 watts.

To clarify, the microwave, etc, would only be used to link dispatch sites together and/or back to the dispatching center. The microwave itself is not used to talk to the train crews, that is strictly on the 160 MHz VHF. The dispatcher sites may be linked via microwave or telephone line, DSL or fiber optics. If you can visualize these high power, high altitude (compared to track level), sites being placed every 20 - 50 miles apart depending on terrain, you will better understand why you can hear the dispatcher and not always the train. The dispatcher has the ability to choose which site they want to use when communicating with the train for best communications. So as a train moves along the line, the dispatcher will change to the nearest site when communicating with the train.

Actually, 20 miles is pretty typical for being able to pick up locomotive communications unless you are very high up on a mountain or other means of getting altitude. I can draw up a picture to illustrate but I think you can get the idea from this!

Hope this makes sense and 73!

 

[kayn1n32008]

I have a question regarding listening to train crews from afar. So I’ve been a railfan for years now, I have good commercial/ ham gear to listen and I understand that dispatchers talk to the crews on the rails via Microwave but I’ve always wondered why I can’t hear the train crews from long distances in the same way that I can hear the NS dispatchers talking from Georgia to Pennsylvania on a microwave frequency. Is there some kind of Microwave (900Mhz) frequency I can tune to so I can hear farther out? With my current setup I can get about 20 miles of coverage. Hope this made sence. Thanks all. KC3MZX

At least where I live, the train to control centre comms occur on simplex frequencies, so there is no repeaters involved. It is a radio site that transmits and listens on the same frequency. You are likely close to one of these sites and can hear it better than you can hear the trains.


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[Kitn1mcc]

The NS dispatch may be covering a wide area and brings up all the base stations when he comms with the trains. also some RR the dispatcher does not answer unless they are dialed up

 

[INDY72]

Most rail transmitters have around 100 foot tall towers, though there are some on top of buildings, or on hills and mountains putting them at higher elevations, with a few as tall as 300/400 foot. These are usually spaced at 20 to 40 miles apart along the tracks (varies with terrain, etc). Most are running simplex or duplex depending on SOP for the rail company, in the 160 MHz range. The Base stations run about 100 Watts output, and as stated mobiles in trains and rail vehicles running 40 to 60 Watts, and HT's running 4 to 10 Watts. Depending on your location in respect to the trackage, and facilities, you can usually get the mobiles and HT's at 10 to 30 miles max, and the Base's at 10 miles and up. Your more likely to get the tone up and Dispatch replies at further ranges than the HT's and Mobiles. Defect Detectors fall in the Mobile's ranges and have the same 40 to 60 Watt output and have usually tiny antennas compared to the primary dispatch, and PBX sites.

 

[kayn1n32008]

Most rail transmitters have around 100 foot tall towers, though there are some on top of buildings, or on hills and mountains putting them at higher elevations, with a few as tall as 300/400 foot. These are usually spaced at 20 to 40 miles apart along the tracks (varies with terrain, etc). Most are running simplex or duplex depending on SOP for the rail company, in the 160 MHz range. The Base stations run about 100 Watts output, and as stated mobiles in trains and rail vehicles running 40 to 60 Watts, and HT's running 4 to 10 Watts. Depending on your location in respect to the trackage, and facilities, you can usually get the mobiles and HT's at 10 to 30 miles max, and the Base's at 10 miles and up. Your more likely to get the tone up and Dispatch replies at further ranges than the HT's and Mobiles. Defect Detectors fall in the Mobile's ranges and have the same 40 to 60 Watt output and have usually tiny antennas compared to the primary dispatch, and PBX sites.

Are you making this **** up as you go? Portables being used by the rail road companies are 5w, maybe 6w depending on the radio they are using. Not 4-10w.

I seriously doubt you will hear a portable reliably at 10 miles, never mind even 5 miles, unless your receiving antenna is 30m or more up, fed with high quality hard line.

Quit making **** up.


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[radioman2001]

Quote"
Portables being used by the rail road companies are 5w, maybe 6w depending on the radio they are using. Not 4-10w.

While not that common today Packset Portables were in the 10 watt range. Today's portable, at least at my agency who turns the power DOWN to 4 watts to save the battery life. Couple that with heliflex antenna's and you are luck to get 1 watt ERP. YMMV

 

[RRR]

I haven't seen a "Packset" in use in about 25 years. They wouldn't be legal after about 2013, as they are not narrowband-able.

DED/HBD's do not run 40 watts either. More like 20~ watts.

And RR freqs. are in the 160 and 161 range

 

[wa8pyr]

Are you making this **** up as you go? Portables being used by the rail road companies are 5w, maybe 6w depending on the radio they are using. Not 4-10w.

I seriously doubt you will hear a portable reliably at 10 miles, never mind even 5 miles, unless your receiving antenna is 30m or more up, fed with high quality hard line. Quit making **** up.

While I concur that one isn't going to hear a portable much more than a few miles away, what he said may be true where he is, so it's really not fair to accuse him of making things up.

There are locations where the antenna might be close to 100 feet in the air but those were often installed many years ago when radio wasn't as heavily used as it is today, everything road and dispatcher-related was on one channel, and the base station was intended to cover a very wide area.

Today, it's different. While some railroads might still use antennas 100 feet or more in the air, with railroads using a common channel plan and nearly everything on carrier squelch, most installations are a lot closer to the ground. Around here, most dispatcher wayside base station antennas are mounted on poles next to the track about every 10-20 miles or so, and are around 30 feet high. Antennas used in yards are even lower, typically only 10-20 feet from the ground so as to limit reception of transmissions from a great distance.

 

[radioman2001]

Quote"
Around here, most dispatcher wayside base station antennas are mounted on poles next to the track about every 10-20 miles or so, and are around 30 feet high.

As is ours, most are 10-15ft up a telephone pole along ROW. Most bases operate with 40-60 watts into anything from unity, Yagi, double Yagi or 4.5db omni antenna, trains run 10 watts with 5 watt ERP (FCC limited) to 40 watts max depending on location and frequency into RR blade antenna, again not the best antenna which effectively cuts the ERP in half. So unless you are next to ROW or at elevation reception at 20 miles is very good.

BTW I am not sure if pack sets are still made by the big name manufacturers, but we have made some of our own in house Post Radios for special projects (Train to Giants Stadium, Fire Brigade) using low power CDM's and APX-7000 mobiles with a LION battery in a Pelican case, and they run 10-15 watts. If I can find the pictures of it I will post them.

 

[DaveNF2G]

The OP seemed to be asking why dispatchers can be heard from several states away but trains cannot.

Wide area repeaters would serve no purpose on the rail lines. The trains need to be heard by the dispatchers wherever they are (like CSX in Jacksonville), but not everywhere else. Trains operating on the same lines can generally hear whoever is on the air close enough to them to be of concern, but they are also kept fully aware of track occupancy by the signals and by the dispatchers if necessary. Train-to-train chit-chat could become a safety hazard.

 

[RRR]

Train-to-train chit-chat could become a safety hazard.

That's a negative, except under excessive circumstances. There is plenty of "Train to train chit chat", as you call it. Anywhere from "hey boss, I thought you was retired?" to "Man, there's a lot of folks up on the hill a mile back", and it's perfectly acceptable.

"Road channels" that these are called, are typically used by Engineers, Conductors, Track guys, signalmen, and that's what they "talk around" on. The dispatcher can also call up the trains, etc. on them as well.

A lot of RR's sometimes will use another channel to go to, to copy track warrants and such. (Sometimes a split pair)

As far as "chit chat" goes, Railroads are a place where plain-talk is very prevalent. I am sure excessive radio usage for BS would be addressed, but it is very unlikely passing trains communicating how each other have been, Conductors wanting the engineer to throw down a sammitch and a coke, etc. would be considered a violation.

 

[Dispatcher308]

I have a question regarding listening to train crews from afar. So I’ve been a railfan for years now, I have good commercial/ ham gear to listen and I understand that dispatchers talk to the crews on the rails via Microwave but I’ve always wondered why I can’t hear the train crews from long distances in the same way that I can hear the NS dispatchers talking from Georgia to Pennsylvania on a microwave frequency. Is there some kind of Microwave (900Mhz) frequency I can tune to so I can hear farther out? With my current setup I can get about 20 miles of coverage. Hope this made sence. Thanks all. KC3MZX

Unfornately no, As others have stated, some use satellite, fiber, DSL, microwave, Copper (ie T-1's to DS0's) If you are indeed in Havre De Grace as your location says it is then you are probably listening to CSX, Amtrak and NS. CSX uses satellite in this area, Amtrak has fiber running up the North East Corridor in this area, and I am not really sure what NS uses, but through Havre De Grace they run on Amtrak track so they would be using Amtrak's fiber.

Most Microwave is 4,6, 11Ghz and higher frequencies. which usually uses digital modulation unmonitorable via a scanner and is most likely also encrypted.

I hope this answer your questions and doesn't go off on some long tangent.

Thanks
Nathan

 

[Kitn1mcc]

at the Valley we are legal to 125watts mobile and base. we used to have some screaming 100watt motorola mitreks . one on the base,one in the motor car,and one in the coal truck. 2013 comes and boom they went with NXDN and lost most of the coverage (some one sold them 25watt mobiles) i come back get 45watt mobiles 45watt base and analog get decent coverage back

 

[kayn1n32008]

at the Valley we are legal to 125watts mobile and base. we used to have some screaming 100watt motorola mitreks . one on the base,one in the motor car,and one in the coal truck. 2013 comes and boom they went with NXDN and lost most of the coverage (some one sold them 25watt mobiles) i come back get 45watt mobiles 45watt base and analog get decent coverage back

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[AK9R]

That's a negative, except under excessive circumstances. There is plenty of "Train to train chit chat", as you call it. Anywhere from "hey boss, I thought you was retired?" to "Man, there's a lot of folks up on the hill a mile back", and it's perfectly acceptable.

Acceptable, but, in my experience, those conversations are short. Back and forth a couple of times. Rarely do I hear a long conversation.

 

[radioman2001]

I loved the 130 watt Micor bases from years ago, but unless you are running bases 50 miles apart or up a very tall tower you don't that kind of power. Due to self interference on some of our lines we have turned most bases down to 10-40 watts. We keep the gain antenna's to pick up portables, but I would like to see the power down to less than 10 watts in some locations.

 

[RRR]

I absolutely agree, that pre-2013, coverage almost everywhere was much better, with "long" antennas on the mobiles, 100+ watt radios, running 25khz wide.

Then the "Narrowband" ruling came into effect, and where we could once talk from a loco to a yard job or tower, we could not. I heard all the B.S. about "You can talk farther on Narrowband" ...Pure baloney. The only statement the radio providers would give is; "Do you really need to talk as far as you did before?"

......Really?

 

[radioman2001]

Quote"
"Do you really need to talk as far as you did before?"

While Railroad and bussiness license users are treated differently the rails are becoming more crowded with increased radio traffic, so lowering the power output cuts range and self interference.
Ever since narrow banding was proposed in the late 80's part of that proposal was to also cut down "area of operation" range with power limitations. One of the school bus companies I maintained saw their license upon renewal go from 110watts 720 ERP down to 22 watts. That happened because as part of the renewal at that time the FCC wanted to know how far from you base/repeater you operated. Foolishly they replied with about 12 miles, causing the FCC to drop their power. After that debacle all my customers licenses had operating ranges at the maximum allowed, and or what the co-ordinator originally allowed.
This was the FCC's first attempt to try and squeeze more users in a given area. Next was narrow banding, which to me is not necessary, but in the 80's we didn't have the cell phone coverage or services that go with it to siphone off about 80% of radio traffic.
Most bussiness license user today are large fleets making it too difficult to use cell or NextHell like services for voice.

 

[nickwilson159]

Due to self interference on some of our lines we have turned most bases down to 10-40 watts. We keep the gain antenna's to pick up portables, but I would like to see the power down to less than 10 watts in some locations.

And even then, it's still an issue between many adjoining territories. But then again, I put much of the blame on radio procedures, specifically the mentality of "more chatter is safer."